fm radio handbook in
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fm radio handbook inTRANSCRIPT
FM Radio DxingNandakumarHobby home publications, Cochin - 22Phone : 9349287808
Price Rs: 100
4
IzmUv B‚n\
Hcp Sn.hn. B‚n\sb°pdn®v ]dbptºmƒ \ΩpsS
a\ nseØp∂Xv bmKn B‚n\bpsS NnXamWv. ssUt]mfw
dn vfIvSdpw UbdIvtSgvkpsa√map≈ bmKn B‚n\bn¬ \n∂pw
hyXykvXamb Hcp B‚n\bmWv IzmUv B‚n\. bmKn B‚n\sb
At]£n®v sNehv Ipdhpw IqSpX¬ ^ehp (better result)ap≈XmWnXv. IzmUv B≥cn\m \n¿ΩmWw hnhcn°p∂Xn\p
ap≥]mbn bmKn B‚n\sb°pdn®v kw£n]vXambn hnhcn°mw.
bmKn B‚n\
P∏m≥Imc\mbncp∂ bmKn F∂ F©n\ob¿ cq]I¬∏\
sNbvX B‚n\bmWv bmKn B‚n\ Hcp dns^vfIvS¿ Hcp
t^mƒUUv ssUt]mƒ, Ht∂m AXne[nItam UbdIvSdpIƒ
F∂nh tN¿∂XmWv Hcp bmKn B‚n\. ChbpsS
Hmtcm∂ns‚bpw \ofhpw Ch XΩnep≈ AIehpw Hmtcm Sn.hn.
kwt]jW ^oIz≥kn°\pkcn®mWv Xocpam\n°s∏Sp∂Xv.
AXmXp ÿesØ Sn.hn. kwt]jW ]oIz≥kn°\pkcn®v
bmKn B‚n\bmbncnI°pw B ÿesØ ISIfn¬ \n∂pw
hmßphm≥ In´p∂Xv.
dn^vsfIvS¿ (Reflector)
bmKn B‚n\bpsS dn vsfIvSdn\mbncn°pw G‰hpw \ofw
IqSpX¬. CXv Aeqan\nbw IpgepIƒ sImt≠m sNºp
IpgepIƒ sImt≠m \n¿Ωn°p∂p. Sn.hn. ]kcWnsb
e£yam°n h®ncn°p∂ bmKn B‚n\bn¬ G‰hpw AIeØn¬
Ccn°p∂Xv dn vsfIvSdmbncn°pw.
2 3
apJ-hpc
inesbt∏mepw Aenbn°m≥ Ignhp≈ kwKoXsØ
CjvSan√mØXv inemlrZb≥am¿ amXambncn°pat√m !
tdUntbmbpsS Imew Ign™p F∂ [mcWbn¬ tdUntbm
X´n≥]pdØv Dt]£n®hcpw, BInISbn¬ hn‰hcpw Ct∏mƒ
F v.Fw. tdUntbm At\zjn®v XpSßnbncn°pIbmWv. kzImcy
taJebn¬ ]pXnb ]pXnb F^v.Fw. tdUntbm tÃj\pIƒ
tIcfØn¬ Bcw`n®v XpSßnbtXmsS hn‰gnbp∂ samss_¬
t^mWpIfn¬ 60 iXam\Ønepw F^v.Fw. tdUntbm
D≈hbmsW∂v I®hS°m¿ km£ys∏SpØp∂p.
F∂m¬ tIcfØns‚ q]IrXnbpsS ]tXyIXaqehpw,
F^v.Fw. tdUntbm XcwKßfpsS t\¿tcJm k©mcKXn
aqehpw, \ΩpsS \m´nse P\kmam\yØn\v Cu ]pXnb
tdUntbm tÃj\pIfn¬ \n∂p≈ ]cn]mSnIƒ
BkzZn°m\mImsX h∂ncn°pIbmWv. CXns\mcp
]cnlmcsa∂ \nebn¬ F^v.Fw. kwKoX t]anIfpw, hnZqc
F v.Fw. tÃj\pIƒ ihn°pI F∂Xv PohnXhrXw t]mep≈
tlm_nbmbn sIm≠p\S°p∂ \nch[n sSIv\ojy≥amcpsS
klmbtØmsS Xømdm°nbncn°p∂ Cu ]pkvXIw, kwKoX
t]anIfmb F^v.Fw. timXm°ƒ°v XßepsS t^hdn‰v
tÃj\pIƒ hy‡ambn e`n°m≥ Bhiyamb kmt¶XnI
⁄m\w e`yam°pw.
5
UbdIvSdpIƒ (Directors)
Hcp bmKn B‚n\bn¬ Ht∂m AXne[nItam
UbdIvSdpIƒ D≠mImw. dn vfIvSdnt\bpw ssUt]mfnt\bpw
Imƒ \ofw Ipd™ UbdIvSdpIfpsS ÿm\w Ch c≠pw
Ign™mWv. UbdIvSdpIfpw Aeqan\nbw As√¶n¬
sNºpIpgepIƒ sIm≠mWv \n¿Ωn°s∏Sp∂Xv.
UbdIvSdpIfpsS FÆw IqSp∂Xn\\pkcn®v B‚n\m sKbn\pw
IqSpsas∂mcp [mcWbp≠v. IqSpX¬ UbdIvSdpIfp≈ \ofw
IqSnb B‚n\ Hcp A¥ mbn Nnesc¶nepw IcpXp∂p≠v.
t^mƒUvUv ssUt]mƒ (Folded Dipole)
dn vfIvSdn\pw UbdIvSdn\pw CS°p hcp∂ Fensa‚mWv
t^mƒUUv ssUt]mƒ. CXpw Aeqan\nbw As√¶n¬ sNºp
Ipg¬ sIm≠mWv \n¿Ωn®ncn°p∂Xv. t^mƒUUv
ssUt]mfns\°pdn®v A¬∏w IqSn a\ nem°p∂Xv
\∂mbncn°pw. lm^v thhv sUt]mfn (Half Wave Dipole) ¬\n∂pamWv t^mƒUUv ssUt]mƒ D≠mbXv.
kwt]jWw sNøs∏Sp∂ CeIvtSm ams·‰nIv
F\¿PnbpsS XcwKcq]w NnXw 4˛¬ sImSpØncn°p∂p. Cu
XcwKØns‚ F\¿Pn Fanj≥ XeØn\v ssd‰v BwKnfmbn
ÿm]n®ncn°p∂ Hcp B‚n\bmWv CXv kzoIcn°phm≥
G‰hpw A\ptbmPyw. Cu XcwKØns‚ IÃv As√¶n¬ S^v
(t]mkn‰ohv As√¶n¬ s\K‰ohv) mKw kzoIcn°p∂Xn\mbn
BsI thhv sewKvXv F∂ Ko°v A£cw sIm≠v
kqNn∏n°ptºmƒ B‚n\bpsS \ofw 1/2 s‚ ]IpXn \ofap≈
B‚n\ D]tbmKn®m¬ AXv \√ Hcp Syq¨Uv k¿Iyq´mbncn°pw.
lm v ssUt]mƒ B‚n\bn¬ AXns\ Xpey\ofap≈
c≠p IjWßfmbn apdn®v Hcp C≥kpte‰n¬, t\cnb
8
ASp-Ø-Xmbn Aep-an-\nbw Ipg¬ aS-°p-hm≥ XpSßmw.
BZyw AS-bm-f--s∏-Sp-Øn-bXv (35 sk.ao.) aS°msX AXn\SpØ
70 sk.ao. ASbmfØn¬ BZyw aS°pI. XpS¿∂v ASpØ 70
sk.ao. ASbmfØnepw aS°pI. At∏mƒ CXv c≠p ImepIƒ°v
\ofw IqSnb (NnXw 6) BIrXnbnembncn°pw. XpS¿∂v BZyw
ASbmfs∏SpØnb (16.75) mKØpw \memasØ ASbmfØn\pw
(16.75) aS°pI. Ct∏mƒ B‚n\ kaNXpcmIrXnbn¬
Bbncn°pw. HcphiØv \Sp`mKØmbn Ipgens‚ AK߃
XΩn¬ t\cnb AIeØn¬ Ccn°p∂XpImWmw. CXp ]ckv]cw
kv]¿in®n´ps≠lvIn¬ Aƒ∏w ]pdtIm´v hf®v AIØWw.
Cu `mKamWv ^oUv t]mbn‚ v. ChnsS\n∂pw thWw ^oU¿
hb¿ AYhm tI_nƒ IWIvSv sNøm≥.
Aeqan\nbw Ipg¬ hfbv°ptºmƒ A¬∏w i≤n°Ww.
tai∏pdtØm, HcpXSn°´bntem h®v AXns‚ AcnIn¬
ASbmfs∏SpØnb`mKw tN¿Øv h®v kmh[m\w hf®m¬
Aeqan\nbw Ipg¬ s]m´nt∏mImsX \∂mbn hfbpw. hf™
`mKw ]c∂ncn°psa∂p amXw. hfbv°phm≥ ]bmkamsW¶n¬
Ipgen\p≈n¬ aW¬ \nd®n´p hf®m¬ H´pw Xs∂
s]m´mXncn°pIbpw sNøpw.
B‚n\bpsS ^oUv t]mbn‚ n¬, ASpØncn°p∂
AK߃ c≠pw Np‰nIbp]tbmKn®v ASnØp ]cØpI. Ch
XΩn¬ t\cnb AIew (Hcp 3 mm) D≠mbncp∂m¬ aXn. ]cØnb
`mKØv Un¬ D]tbmKn®v sNdnb Zzmc߃ CSpI.
Cu Zzmcßfn¬ ]n®f (Brass) \´pw t_mƒ´pap]tbmKn®v
Hmtcm SmKpIƒ Dd∏n°Ww. (SmKv As√¶n¬ seKv
sNºpsIm≠p≠m°nbn´p≈Xpw hen∏w IqSnb AKw
\´pwt_mƒ´pw D]tbmKn®v Dd∏n°p∂Xn\pw hen∏w Ipd™
6
AIeØn¬ (1/4 skao.) Øn¬ Dd∏n®ncn°p∂p. t\csØ
kqNn∏n®ncn°p∂Xpt]mse Aeqan\nbw/sNºp IpgemWnXn\p
]tbmKn°p∂Xv.
CØcsamcp lm^v thhv ssUt]mfns‚ sk≥S¬
Cw]U≥kv GItZiw 72 Hmwkv Bbncn°pw. t]mtbmKnIambn
CXv 75 Hmwkv F∂v IcpXnt∏mcp∂p.
c≠v lm^v thhv ssUt]mƒ B‚n\Iƒ tN¿Øv
\n¿Ωn°p∂XmWv t^mƒUUv ssUt]mƒ. t^mƒUUv
ssUt]mfns‚ sk≥S¬ Cw]U≥kv 288 Hmwkv AYhm
]mtbmKnIambn 300 Hmwkv Bbncn°pw.
IzmUv B‚n\
bmKn B‚n-\-bpsS ][m\ \yq\-X-bmb Cw]-U≥kv ankv
am®nwKv ]cn-l-cn-®p-sIm-≠p≈ Hcp B‚n-\-bmWv IzmUv B‚n-
\. F∂o ta≥a-Ifpw CXn-\p-≠v. B‚n-\bpw dn^vf-IvSp-amXw
D]-tbm-Kn-®m¬ ^n©v Gcn-bm-bn¬ t]mepw \∂mbn FM kwt]-
jWw kzoI-cn-°m≥ Ign-bp-∂p-≠v. IzmUv B‚n-\-bpsS sk≥S¬
Cw]-U≥kv 75 Bbn-cn-°pw. ]e ]T-\-ß-fn¬ \n∂pw a\- n-em-
°p-∂Xv IzmUv B‚n-\°v bmKn B‚n-\-sb-°mƒ 2dB sKbn≥
IqSp-X¬ Ds≠-∂m-Wv.
bmKn B‚n-\-bpsS \n¿Ωm-W-Øn-se-∂-t]mse CXnepw
Aep-an-\nbw As√-¶n¬ sNºv Ipgp-ep-I-fmWv D]-tbm-Kn-°p-∂-
Xv. sNºv Ipg-ep-Iƒ BsW-¶n¬ Xn≥ hmƒ ssS∏v (Thinwall type)aXn-bmIpw.
sNºp Ipg-ep-Iƒ Ce-IvtSm-tπ‰v sNøp-∂Xv \∂mbncn-°pw.
sNºp-Ip-g-ep-Iƒ°v Xmc-X-tay\ hne IqSp-X-em-bn-cn-°p-sa-∂-Xn-
\m¬ Aeq-an-\nbw Ipg-ep-Iƒ D]-tbm-Kn-°mw. Aeq-an-\nbw Ipg-
7
ep-Iƒ 9mm (3/8
”) hen-∏-ap-≈-h-bmWv D]-tbm-Kn-°p-∂-Xv. B‚n-
t\bpw XΩn¬ _‘n-∏n-°p-∂-Xn\v 1/2
” ]nhnkn ss]∏p-I-fmWv
D]-tbm-Kn-°p-∂-Xv.
\n¿ΩmWw
sIm®n≥ F^v.Fw. Sm≥kvan-‰-dn¬ \n∂p-ap≈ kn·-ep-
Iƒ kzoI-cn-°m-\p≈ Hcp IzmUv B‚n-\-sb-°p-dn®v BZy-ambn
hnh-cn-°mw. BImihmWn 102.3 ¬ kwt]-jWw sNøp∂
BImihmWn sIm®n, ^n©v Gcn-bm-bn¬ t]mepw, e`n-°p-
hm≥ Cu B‚n-\bpw dn^vf-IvS-dp-w amXw aXn-bm-Ipw.
B‚n\
IrXyw 280 sk. an. \of-ap≈ 9 mm As√-¶n¬ 3b8 C©v
Aeq-an-\nbw Ipg¬ sIm≠mWv CXn-\p-th-≠n-bp≈ B‚n\m
\n¿Ωn-t°-≠-Xv. Cu Ipg-ens\ ka-N-Xp-cm-Ir-Xn-bn¬ aS-°-Ww.
At∏mƒ Hmtcm hihpw 70 sk.-an. \ofw hcp-sa∂p ImWmw.
F∂m¬ B‚n-\-bpsS oUv t]mbn‚ v (^oU¿ hb¿ IW-IvSv
sNtø≠ ÿew) Hcp hi-Øns‚ a≤y- m-K-Ømbn htc-≠-Xp-
≠v. AXn-\m¬ Xmsg-s°m-Sp-Øn-cn-°p∂ Af-hp-Iƒ Aep-an-\nbw
Ipg-en¬ am¿°¿ sIm≠v AS-bm-f-s∏-Sp-Øn-bn v hf-bv°p-∂-XmWv
\√-Xv.
Hc-KØv \n∂pw 35 sk. an. AS-bm-f-s∏-Sp-Øp-I. AhnsS
\n∂pw 70 sk. an AS-bm-f-s∏-Sp-Øp-I. XpS¿∂v c≠v 70 sk. an.
AS-bm-f-s∏-Sp-Øp-I. _m°n-bp≈ `mK-Øn\v 35 sk. an. Bbn-
cn°pw \ofw.
9
AKw tkmƒU¿ sNøp∂Xn\pw, ]‰p∂XcØnep≈XmWv.
Sm≥kvt^m¿adpIfn¬ \n∂pw tNkn nte°v IWIvSv
sNøp∂Xn\pw Hmt´msamss_epIfnepw CXv
D]tbmKn°p∂p≠v.) Chbn¬ H∂ns‚ AKØn¬
tIm˛BIvknb¬ tI_nfns‚ tImdpw at‰Xns‚ AKØn¬
jo¬Upw tkmƒU¿ sNbøWw. bmKn B‚n\mbnset∏mse
\´pw t_mƒ´pw D]tbmKn®v oU¿ hb¿ IWIvSp sNbvXm¬
t]mcm. tkmƒU¿ sNøpI Xs∂ thWw. tIm˛BIvknb¬
tI_nfns‚ at‰ A‰Øv Snhn, B‚ n\ tkm°‰n¬
IpØp∂Xn\mbn Hcp ]n∂n¬ IWIvSp sNøWw.
IzmUv B‚n\m kwt]£Ww sNøp∂ tÃjs‚
B‚n\mbv°v A`napJambn thWw ^n©v Gcnbbn¬ 10 ao‰¿
DbcØnse¶nepw Cu B‚n\ ^n‰v sNøm≥ ian°pI. Cu
B‚n\tbmsSm∏w _qÿ D]tbmKnt°≠ Bhiyan√.
D]tbmKnt°≠ Bhiyan√. D]tbmKn°pIbmsW¶nev 75
Hmwkv C≥]p´v/Hu´v]p´v Cw]U≥kp≈ _qÿ Xs∂
D]tbmKn°Ww. DZmlcWw more FM Ãocntbm _qÿ.
F^v.Fw. kn·epIfpsS k©mc]Yw
t\¿tcJbn¬ amXta k©cn°pIbp≈q F∂ F v.Fw.
tdUntbm XcwKßfpsS ]tXyIX ImcWw FXi‡nIqSnb
Sm≥kvan‰¿ D]tbmKn®mepw `qanbpsS I¿th®¿aqew 50
Intemao‰¿ ZqcØnepw A∏pdtØ°v Hcp F v.Fw. tÃj\nse
]t£]Ww FØpI F∂Xv Xnbdn‰n°embn ]mtbmKnIa√.
kkyeXmZnIƒ F^v.Fw. kn·epIsf \∂mbn BKncWw
sNøpw F∂Xpw, Ip∂pw, aebpw, Xmgvhmcßfpw \nd™
tIcfØns‚ q]IrXnbpw Cu 50 Intemao‰¿ F∂ Zqc]cn[nsb
ho≠pw Ipdbv°p∂p. Aßs\ hcptºmƒ Hcp F^v.Fw.
tdUntbm kvt‰j\n¬ \n∂pap≈ ]t£]Ww km[mcW
12
AdnbmØXv F∂pw. At∏mƒ Dxing \v AdnbmØ Zqcw F∂
A¿∞w e`n°p∂p.
F^v. Fw. tdUntbm Dxing efnXamb am¿§ßƒ
1. sk≥kn‰nhn‰n IqSnb dnkohdpIƒ D]tbmKn°pI
F∂XmWv G‰hpw efnXamb am¿§w, Im¿
ÃocntbmIfmWv G‰hpw sk≥kn‰nhn‰n D≈ F v.Fw.
tdUntbm sk£\pIƒ ASßnbncn°p∂Xv AXn\m¬
Im¿ÃocntbmIƒ ho´n¬ D]tbmKn®m¬ sa®s∏´
coXnbn¬ F v.Fw. ihn°mw.
2. Kmßv I¨≥k¿ F∂ SyqWnwKv kwhn[m\ap≈
tdUntbmIƒ D]tbmKn°pI. kvIm\nwKv tdUntbmIƒ°v
km[mcWKXnbn¬ sk≥kn‰nhn‰n Ipdhmbncn°pw.
3. ho´n¬ \nehn¬ sSenhnj≥ B‚n\Iƒ
D]tbmKn°p∂ps≠¶n¬ AXn¬ \n∂v Hcp hb¿ IWIvSv
sNbvXv tdUntbmbpsS Gcnbepambn _‘n∏n°pI.
4. sa‰¬ t_mIvkn¬ Akw_nƒ sNbvXv Hmt´mdn£Iƒ,
_kpIƒ XpSßnb hml\ßfn¬ n‰v sNøp∂Xn \mbn
e`n°p∂ Xcw sU¬ln tdUntbmIƒ D]tbmKn°pI.
CØcw tdUntbm hmßptºmƒ tkmWn, ^nen]vkv,
XpSßnb Iº\n IC D≈h hmßcpXv, ssN\m IC D≈h
Xs∂ thWsa∂v IS°mct\mSv ]tXyIw ]d™v
hmßWw. \njn° CeIvtSmWnIvkv sU¬ln CØcw
sslsk≥kn‰n hn‰n dnkohdpIƒ \n¿Ωn°p∂p≠v.
5. ]gbXcw F v.Fw. tdUntbmIƒ D]tbmKn°pI.
Ct∏mƒ hcp∂ F^v.Fw. tdUntbmIfn¬ IF sk£≥
F∂ SyqWnwKv hn`mKw IC IfmWv ssIImcyw sNøp∂Xv.
10
B‚n\Iƒ D]tbmKn®v kzoIcn°mhp∂ ]cn[n 25˛30
Intemao‰dpIƒ amXambn Npcpßp∂p.
NnXw 1 t\m°pI F^v.Fw. tdUntbm tÃj\n¬ \n∂v
50 Intemao‰¿ Ign™m¬ F v.Fw. kn·epIƒ e`yamsW¶n¬
t]mepw AXv iq\ymImiØnte°v \jvSamhpIbmsW∂v
ImWmw. At∏mƒ NnXw 1 se hoSv F.bn¬ F^v.Fw. tÃj≥
e`yamhWsa¶n¬ hoSn\v apIfn¬ Hcp B‚n\ ÿm]n®m¬
aXnbmIp∂XmWv.
11
aeIfpw, Ip∂pIfpw, ^vfm‰v kap®bßfpw F^v.Fw.
kn·epIsf XS s∏SpØp∂p. hoSv F˛bnepw _n˛bnepw
D≈h¿°v F^v.Fw. tdUntbm ihWw _p≤napt´dnbXmbn
amdnbnbncn°p∂p. NnXw 3 t\m°pI. hoS v F, _n.
F∂nhSßfnse Xmak°m¿°v \√coXnbn¬ \n¿Ωn® F v.Fw.
B‚n\ D]tbmKnt°≠nhcpw.
F^v.Fw. tdUntbm Dxing
hnZqcXbn¬ \n∂p≈ F v.Fw. tÃj\pIƒ tIƒ°pI
F∂Xv Hcp hyXykvXamb tlm_nbmWv.temIØns‚
hnhn[`mKßfn¬ CXpt]mep≈hcpsS Iq´mbva ¢∫pIƒ
]h¿Øn°p∂p. hmcm¥yßfn¬ GsX¶nepw aeapIfn¬ HØv
IqSn X߃ \n¿Ωn® D]IcW߃ D]tbmKn®v hfsc
hnZqcXbn¬ \n∂p≈ F v.Fw. tÃj\pIƒ ihn®v IqSpX¬
tÃj\pIƒ°mbn XßfpsS D]IcW߃ Syq¨
sNbvXpsIm≠ncn°pw CØc°m¿.
hnZqcXbn¬ \n∂p≈ tdUntbm ]t£]W߃
kzoIcn°p∂Xns\bmWv tdUntbm Dxing F∂v ]dbp∂Xv.
CXnse D F∂Xv Distance F∂Xns‚ Npcp°amWv X F∂m¬
13
CXv \ap°v ]pdØv \n∂v Syq¨ sNøm≥ km[n°n√.
]gb F v.Fw. tdUntbmIfnse IF sk£\pIƒ \ap°v
Hcp Asse≥sa‚ v kvIq ssUh¿ D]tbmKn®v \∂mbn
Syq¨ sNøm≥ km[n°pw. CXpaqew ho°mbn e`n°p∂
tdUntbm tÃjs‚ dnk]v£≥ \ap°v sa®s∏SpØm≥
km[n°pw.
6. dm_n‰v Cb¿ B‚n\ D]tbmKn°pI.
t]m¿´_nƒ sSenhnj\pIfn¬ D]tbmKn°p∂Xcw
dm_n‰v Cb¿ sSenkvtIm∏nIv B‚n\ D]tbmKn°pI.
CØcw B‚n\Iƒ AXns‚ BapIƒ Db¿Ønbpw
XmgvØnbpw, s]mknj≥ am‰nbpw h®m¬ \√ dnk]v£≥
e`n°pw. sslsk≥kn‰hn‰n dnkohdpIƒs°m∏w
D]tbmKn®m¬ \√ dnkƒ´v e`n°pw.
7. vfm‰v hb¿ D]tbmKn°pI
B‚n\bn¬ \n∂v tdUntbmbnte°v IW£≥
sImSp°m≥, ]gbIme ªm°v & ssh‰v sSenhnj≥
B‚n\ IWIvSv sNøm≥ D]tbmKn®ncp∂ dn_¨
tI_nƒ ( vfm‰v hb¿) D]tbmKn°pI. CXn\p]tbmKn
°p∂ tI_nƒ \√ KpWta≥abp≈Xmbncn°Ww.
hg°ap≈Xmbncn°Ww. (hfsc Ãn^mbncn°p∂h
tamiw tIm∏¿ D]tbmKn®Xmbncn°pw)
8. \ofw BhiyØn\v amXw
F^v.Fw. B‚n\bn¬ \n∂v tdUntbmbnte°p≈
hbdns‚ \ofw BhiyØn\v amXta BImhq. Cu hb¿
Npcp´n hbv°pItbm, \neØnSpItbm sNøp∂Xv
dnk]v£≥ Izmfn‰n tamiam°pw.
16
tIƒhn-bpsS BtLm-j-ambn C\n
F^v Fw XcwKw
\jvS-s∏´ ]uUn-bn-te°v ]pXnb F^v Fw Xcw-K-Øn-
eqsS Xncn®p \S-°p-I-bmWv tdUn-tbm. kmt¶-XnI IpXn-
∏n¬ CSbv°v Fhn-sStbm ssItamiw h∂ knwlm-k\w
Xncn-®p-]n-Sn-°m-\p≈ Ah-k-camWv tdUn-tbm°v Hcp-ßn-
bn-cn-°p-∂-Xv.
ap≥X-e-ap-d-bpsS Krlm-Xpc kvac-W-I-fn¬ \nd™p \n¬°p-
Ibpw B[p-\n-IbpK-Øn¬ \ndw aßn-t∏m-Ip-Ibpw sNbvX tdUn-
tbm-bpsS AXn-i-‡-amb Xncn-®p-h-c-hn\v km£yw hln-°m-s\m-cp-
ßp-I-bmWv ]pXnb Imew. \jvS-s∏´ ]uUn-bn-te°v ]pXnb F^v
Fw Xcw-K-Øn-eqsS Xncn®p \S-°p-I-bmWv tdUn-tbm. kmt¶-Xn-I-
Ip-Xn-∏n¬ CSbv°v Fhn-sStbm sh®v \jvS-amb knwlm-k\w Xncn-
®p-]n-Sn-°m-\p≈ Ah-k-c-amWv tdUn-tbm°v Hcp-ßn-bn-cn-°p-∂-Xv.
tIc-f-Ønse BZy kzmImcy F v Fw tÃj-\mb tdUntbm
amwtKm 91.9 ]t£-]Ww XpSßn-b-tXmsS F^v. Fw tdUntbm
cwKØv hnπ-h-I-c-amb am‰-Øn\pw a’-c-Øn\pw Ac-sßm-cp-ßp-I
-bm-Wv. ae-bmf at\m-c-a-bpsS Cu F^v. Fw kwcw`w tImgn-t°mSv
\K-c-Øn\v 50 Intem-ao-‰¿ Np‰-f-hn-ep≈ timXm-°ƒ°v e`y-am-hpw.
tIc-f-Øn¬ ]h¿Ø-\m-\p-aXn e`n® 17 kzImcy F v Fw tdUntbm
tÃj-\p-I-fn¬ BZy-tØ-XmWv tdUntbm amwtKm.
k¨ s\‰vh¿°ns‚ tdUntbm _m≥Umb 93.5 Fkv F^v
Fw tImgn-t°m-Sp-\n∂v Unwkw-_¿ Ggv apX¬ ]t£-]Ww XpSßn-
°-gn-™p. sslZ-cm-_m-Zv, _mw•q¿, Pbv]q¿, qh-t\-iz¿, I´-°v, Xncp-
∏-Xn, eIv\u, t`m∏m¬ XpS-ßnb \K-c-ß-fn¬ XcwKw Xo¿Ø
_m≥UmWv 93.5 Fkv F^v Fw. C¥y-bnetßm-f-an-tßm-f-ap≈ 31
14
9. kn.Un., Un.hn.Un, Sn.hn. , Iºyq´¿ apXembh
]h¿Øn°ptºmƒ F^v.Fw. dnk]v£≥
tamiambncn°pw. BbXn\m¬ C‚¿^nbd≥kv
D≠m°p∂ D]IcW߃ Hm v sNbvXnSpI.
10. sshZypXn sse\pIfpsS ASnbn¬ B‚n\ n‰v sNøcpXv.
sshZypXn sse\pIfpambn kpc£nXamb AIew
]men°pI.
F^v.Fw. ssUt]mƒ B‚n\
G‰hpw efnXamb Hcp hn`mKw B‚n\IfmWv ssUt]mƒ
B‚n\Iƒ. 9 mm (3/8) Aepan\nbw ss]∏v D]tbmKn®v Ch
\n¿Ωn°mw. (km[mcW FIvtÃW¬ Snhn B‚n\Ifn¬ hf™
BIrXnbn¬ ImWp∂XmWv ssUt]mƒ)
F^v.Fw. eq∏v B‚n\
3/20 CeIvSn°¬ hb¿ D]tbmKn®v hfsc efnXambn
\n¿Ωn°mhp∂ Hcn\w B‚n\bmWv eq∏v B‚n\. 88 apX¬ 108
MHz hscbp≈ F√m ^oIz≥knbpw H∂n®v e`yamIp∂ Hcp
sshUv _m≥Uv B‚n\bmWnXv. AXn\m¬ \nßfpsS ]tZiØv
e`yamIp∂ GXv tÃj\pw Cu B‚n\ D]tbmKn®v hyIyambn
kzoIcn°mw.
70 sk.ao. \ofap≈ c≠v ]´nI IjW߃ Cu B‚n\
\n¿Ωn°m≥ BhiyamWv. Ch NnXØn¬ ImWp∂ coXnbn¬
tImkv tPmbn‚ v sNbvXv Dd∏n°pI. CXns\ amÃv F∂v
hnfn°pw. Cßs\ \n¿Ωns®Sp°p∂ B‚n\ amÃn¬ H∂c
C©ns‚ BWnIƒ Xdbv°pI. B‚n\ \n¿Ωn°m≥
D]tbmKn°p∂ hb¿ ssKUv sNøp∂Xn\v th≠nbmWv BWn
Xdbv°p∂Xv. NnXØn¬ hb¿ ^n‰v sNbvXncn°p∂ coXn
15
\∂mbn t\m°n a\ nem°nbXn\v tijw Ãm¿´v F∂
t]mbn‚nse BWnbn¬ sIm≠v h∂v Ahkm\n∏n°pI. Ãm¿ v
F∂ t]mbn‚n¬ hb¿ n‰v sNøm≥ \Ωƒ D]tbmKn°p∂ 3/
20 CeIvSn°¬ hbdns‚ A¬∏w C≥kptej≥ If™v
BWnbn¬ \∂mbn ]ncn®v Dd∏n°mw. End t]mbn‚nepw Cßs\
sNøWw. B‚n\ \n¿ΩmWØn\v tijw Cu t]mbn‚pIƒ,
B‚n\ tI_nfpambn tkmƒU¿ sNbvXv Dd∏n°mw. As√¶n¬
\∂mbn C≥kptej≥ tS∏v H´n®mepw aXn. sh≈w Cdßn eqkv
tIm¨SmIvSv D≠mImXncn°m≥ th≠nbmWnXv. amÃnse hb¿
IS∂v t]mIp∂ a‰v ssKUnwKv BWnIfn¬ hb¿ sNºv Iºn
D]tbmKn®v sI´n Dd∏n®m¬ aXnbmIp∂XmWv.
B‚n\ \n¿Ωn°m\mbn GItZiw 31/2 ao‰¿ 3/20 hb¿
\ap°v BhiyamWv. BZyambn Cu hb¿ \√ shbneØv c≠v
aq∂v aWn°q¿ hen®v sI´nbnSpI. NqSmIptºmƒ hb¿ henbpw.
Cu hb¿ FSpØv DS≥Xs∂ amÃn¬ eq∏v sNøpI. Endt]mbn‚n¬ FØnbXn\v tijw _m°nbp≈ hb¿ apdn®v
IfbpI. shbneØn´v kok¨ sNømØ hb¿ D]tbmKn®v
B‚n\ \n¿Ωn®m¬ shbnte¬°ptºmƒ B‚n\ hb¿ eqkmbn
dnk]v£≥ tamiamIm≥ CSbp≠v.
eq∏v B‚n\ amÃn¬ \∂mbn hpUv ss]adpw
s]bn‚paSn°p∂Xv Zo¿LIme CuSv \n¬∏n\v BhiyamWv.
Cu B‚n\bpsS X ASbmfØn\v ]n∂nembn GI ¢mºpIƒ Xd®v
B‚n\ ss]∏n¬ Db¿Øn DbcØn¬ LSn∏n°mw.
17
\K-c-ß-fn¬°qSn ]t£-]Ww hym]n-∏n-°m≥ Hcp-ßp-I-bmWv Fkv.
F^v Fw.
Gjy-s\-‰ns‚ s_Ãv F^v Fw 95 Xriq-cnepw IÆq-cnepw
]t£-]Ww Bcw- n-®p. Kƒ v \mSp-I-fn¬ kzmIcy tdUntbm ]t£-
]-W-hn-π-h-Øn\v t\XrXzw \¬In Ct∏mƒ Xs∂ Gjy-s\‰v
tdUntbm ]t£-]-W-Øn¬ kPo-h-am-Wv.
kzImcy F^v. Fw tdUntbm tÃj-\p-I-fpsS hc-thmsS
timXm-°ƒ°v tdUntbm ]pXnb A\p- -h-ambn amdp-sa-∂mWv hne-
bn-cp-Ø-s∏-Sp-∂-Xv. Hcp ImeØv F√m hoSp-I-fn-tebpw km∂n-≤y-am-
bn-cp∂ tdUntbm AXn¬ Ihn™ kzm[o\w kao] `mhn-bn¬
t\Sp-sa-∂mWv ]pXnb sS‚ v kqNn-∏n-°p-∂-Xv. bph-Xz-Øns‚ apJ-
ap-Z-bmbn amdnb samss_¬ t^mWn¬ F v.Fw e`y-am-hp∂p F∂-
Xv CXns‚ ]nbw Db¿Øpw. bmXm-th-f-I-fn¬ timXm-hns\ ]n≥Xp-
S-cp∂ km∂n-≤y-ambn hml-\-ß-fnepw F^v Fw ÿm\w t\Sn-°-
gn™p.
^oIz≥kn tamUp-te-j≥ kmt¶-Xn-I-hn-Zy-bn-emWv ]pØ≥
tdUntbm A\p-`-h-Øns‚ \nZm-\w. tdUntbm \ne-b-Øn¬ \n∂v
40 apX¬ 100 hsc Intem-ao-‰¿ Np‰-f-hn¬ Cu coXn-bn¬ ]t£-
]Ww km[y-am-hpw. 87.5 MHz \pw 108 MHz \pw CS-bn-ep≈
^oIz≥knbmWv F v Fw ]t£-]Ww kzoI-cn-°m\mhpI. XcwK-
ssZ¿Lyw Ipd-hm-b-Xn-\m¬ a‰p XS- -߃ i_vZsØ kmc-ambn
_m[n-°m-dn-√. AXp-sIm-≠pXs∂ F^v Fw ]t£-]Ww UnPn-
‰¬ hy‡-X-tbmsS e`y-am-hp-∂Xv.
tdUntbm k¶¬∏-Øns‚ AXn-cp-Isf t`Zn-°p∂ ihym-
\p-`-h-amWv F^v Fw ]I¿∂p \¬Ip-hm≥ Xøm-sd-Sp-°p-∂-Xv.
\hkmt¶-XnI ]n≥_-e-tØm-sS-bmWv tdUn-tbm-bpsS ]pXp-X-cwKw
IS-∂p-h-cp-∂-Xv. ]t£-]W Ie-bn¬ tdUntbm tPm°n-I-fpsS
hmKvNm-Xp-cy-Øns‚ A\p-`-h-X-ehpw C\n bmYm¿∞y-am-hp-I-bmWv.
20
CXn¬ ]m´p-Iƒ, kao-]-ÿ-e-ß-fnse aX-]-chpw cmjvSo-bhpw kmw-
kv°m-cn-I-hp-amb NS-ßp-I-fpsS Adn-bn-∏p-Iƒ, ka-Im-enIw F∂-
t]-cn¬ hm¿Øm hni-I-e\w, B-tcm-Ky-hn-h-c-߃ AS-ßnb
sl¬Øv Sn]vkv, Km-‘n-b≥ Nn¥-Iƒ ]¶p-sh-°p∂ Km‘n-t]m-
Kmw,- Xo-h≠n kabw XpS-ßn-b-h-bm-Wp-≈-Xv.- X-ß-fpsS kz¥w aoUn-
b- F∂ tXm∂¬ P\-߃°n-S-bn¬ hf¿Øn-sb-Sp-°m≥ sIm®n
F^v.-Fw. \p Ign-™p. sImta-gvkvsse-tk-js‚ `mK-ambn h∂
t^m¨ C≥ t]mKm-ap-I-fnse A\u¨k¿amtcmSv kz¥w ]iv\-
߃ IpSpw-_-Ønse H-cw-K-Øn-t\m-sS∂ \ne-bn¬ t]£-I¿ ]¶p-
sh-°m-dp-≠-tX.
kzmImcy F v.-Fw. Nm\-ep-Iƒ h∂mepw P\-߃°v sIm®n-
\n-e-b-tØm-Sp≈ hnizm-kyX AXn\v apX¬°q-´mhpw. CXv Cu
k¿°m¿ tÃj\v hfsc KpWw sNøp-Ibpw sNøpw. ]t£ BIm-
i-hm-Wn-bpsS \yqkv Gsd sa®s∏Sp-tØ-≠-Xp-≠v. C\nbpw AXv
s]m^-j-W¬ Bbn-´n-√. Hcp-k¿°m¿ kYm-]-\-Øn\v kl-P-am-bn-
´p≈ \qem-am-e-I-fm-Wvt]m-Km-ap-Isf k¿§m-fl-I-am-°p-∂-Xn\v
Ch¿°v XS- w. Ct∏gpw hbepw hoSpw, Ihn-Xm-]m-cm-bWw, ¢m-kn-
°¬ kw-KoXw XpS-ßnb ]cºcmKX ]cn-]m-Sn-I-fn¬ IpSp-ßn-°nS°p-
I-bm-Wv. CØcw t]mKm-ap-Isf ssI-søm-gn-b-W-sa-∂-√. AXv \ne-
\n¬s° Xs∂ IqSp-X¬ anI® ]cn-]mSnIƒ \¬Ip∂ hn[-Øn¬
sshhn-[y-h¬°-cn-°Wwhtc-≠-Xp-≠v. km‰-sse‰v tdUntbm
bmYm¿∞yambn-cn -°p∂ C°m-eØv, C¥y-bn¬ CX-b-[nIw
B¿ss°hvkv tcJIƒ kq£n-°p-∂ BIm-i-hm-Wn°v Hcp
tdUntbm Nm\¬ km‰v-sse‰v aptJ\ XpS-ßm-hp-∂-Xm-Wv. Ct∏mƒ
hy‡n-Iƒ apX¬ ÿm]-\-߃ hsc km‰-sse‰v tdUntbm XpS-ßn-
bn-´p-≠v. ]©m-_n-Iƒ°v amX-ambn \S-Øp∂ ]©m_v tdUntbm
CØ-c-Øn-ep-≈-Xm-Wv. amdnb kml-N-cy-Øn¬ BIm-hm-Wn-bpw a’-
c-Øn-\n-d-ßp-tºmƒ AXv ]ªnIv tdUntbm F∂ k¶¬∏sØ A´n-
a-dn-°ptamsb∂v ImØn-cp-∂p-Im-W-Ww.
18
Xncp-h-\-¥-]p-cw, sIm®n, Xriq¿, tImgn-t°m-Sv, IÆq¿ F∂o
A©v \K-c-ß-sf-bmWv tIc-f-Øn¬ 17 F^v Fw ^oIz≥kn-Iƒ
A\p-h-Zn-°-s∏- n- p-≈-Xv. CXn¬ ae-bmf at\m-c-a, amXr- q-an, k¨Kq-
∏ns‚ Im¬ tdUntbm F∂nh \mev ^oIz≥kn-Iƒ hoXhpw Gjym-
s\-‰v, AUvem_vkv F∂nh c≠v ^oIz≥kn-Iƒ hoXhpw tdUntbm
an¿®n Hcp ^oIz≥kn-bp-amWv kz¥-am-°n-bn-´p-≈-Xv. ae-bmf at\m-
ca sIm®n, Xriq¿, tImgn-t°m-Sv, IÆq¿ F∂n-h-S-ß-fnepw amXr`qan
Xncp-h-\-¥-]p-cw, sIm®n, Xriq¿, IÆq¿ F∂n-h-S-ß-fnepw F^v
Fw tÃj-\p-Iƒ°p≈ ssek≥kv t\Sn-bn-´p-≠v. Xncp-h-\¥]p-cw,
Xriq¿, tImgn-t°m-Sv, IÆq¿ F∂n-h-S-ß-fn¬ F^v Fw
tÃj≥ XpS-ßm-\mWv Im¬ tdUntbm ssek≥kv t\Sn-b-Xv. Gjym-
s\-‰n\v Xriq¿, IÆq¿ F∂n-h-S-ß-fnepw F v Fw \ne-b-߃ Bcw-
`n°m\mWv ssek≥kv e`n-®n-´p-≈-Xv. tdUntbm an¿®n°v Xncp-h-\-
¥-]p-c-ØmWv ]h¿Ø-\m-\p-aXn e`n-®-Xv. Ch-sb√mw bmYm¿∞y-
am-bm¬ tIcfw tIƒhn-bpsS BtLm-j-Øn-te°v IS-°p-sa∂v \nkw-
ibw ]d-bmw.
C\n F^v Fw tdUn-tbm-Iƒ kuP-\y-ambpw
kzImcy F^v Fw tÃj-\p-Iƒ C∂v tIcfw Iø-S-°m-\p≈
Hcp-°-Øn-em-Wv. 17-˛-Hmfw ÿm]-\-߃°v k¿∆okv XpS-ßm\p≈
A\p-aXn In´n-°-gn-™p. CXn-\n-S-bn¬ h¿j-ß-fmbn k¿°m-cn-s‚
]cn-an-X-amb hn -h-ß-fn¬ \n∂p-sIm≠v Hcp tÃj≥ AXns‚ hnPbw
]d-bp-∂p-≠v. sIm®n-bnse F^v Fw tdUntbm tÃj≥ 1989 HIvtSm-
_¿ H∂n-\mWv CXv Bcw-`n-°p-∂-Xv. tIc-f-Øn¬ At∏m-gp-≠m-bn-cp-
∂ tdUn-tbm-\n-e-b-ß-sfm-s°bpw aoUnbw thhn-em-bn-cp-∂p. tÃj-
\p-I-sf-Xs∂ aq∂mbn Xncn-®n- p-≠v. tem°¬, t\m -- tem°¬, doPn-
b-W¬. CXn¬ IÆqcpw tZhn-Ip-fhpw t\m¨ ˛ tem°¬ BWv.
tImgn-t°m-Sv, Xncp-h-\-¥-]p-cw, Xriq¿ F∂nh doPn-b-W-epw.
sIm®nsb Hcn-°epw tem°¬ C\-Øn¬s∏Sp-tØ-≠-Xn-√. CXns\
tem°¬ B°n-b-tXmsS Xs∂ AXn-s‚ XpS°w ]m-fn. sIm®n-
bpsS Pntbm- -s]m-fn-‰n-°¬ ]m[m\yw Chn-SpsØ cmjvSob ]h¿Ø-
19
Itcm a‰v A[n-Im-cn-Itfm Xncn-®-dn-bm-Ø-XmWv Imc-Ww. hfsc
Ipd™ ^≠pw Ipd™ Ãm^p-IfpamWv sIm®n-°p-≠m-bn-cp-∂-Xv.
sIm®n tÃj≥ Bcw- n-°p-∂Xv ChnSpsØ ao≥]n-Sp-Ø-°msc D∂w
sh®p-sIm-≠m-Wv. Hcp sNdnb ]cn-[n-°-IsØ Imcy-ß-ƒ amXw
ssIImcyw sNøp-I. doPn-b-W¬, t\m¨˛tem-°¬ tÃj-\p-Iƒ°v
KpW-ta-∑-bp≈ ÃpUn-tbm, a‰v C≥^m-kvS-I-N¿ kuI-cy-߃ \¬Ip-
tºmƒ tIc-f-Øns‚ hmWnPy Xe-ÿm-\-amb sIm®nsb A[n-Ir-
X¿ Ah-K-Wn-®-Xn\vsd ^e-amWv \n m-c-amb hn`-h-ßfpw D]-I-c-
W-ßfpw amXw A\p-h-Zn®v sIm≠v Cu tÃj≥ XpS-ßn-bXpw C∂pw
tem°¬ ]Z-hn-bn¬ Xs∂ XpS-cp-∂-Xpw. BZy-Im-e-ß-fn¬ H‰
Sm≥kvan-js\ D≠m-bn-cp∂p≈p. sshIn v 6 apX¬ 9.30 hsc. ]n∂oSv
cmhnse 6 aX¬ 9 hscbpw Sm≥kvan-j≥ XpS-ßn. tIµ-Ønse
A[n-Im-cn-Iƒ tem°≥ tÃj\v c≠v Sm≥kvan-j≥ th≠ F∂
ImcWw ]d™v cmhn-e-tØXv d±v sNbvXp. ]s£ At∏m-tg°pw
P\-ß-fpsS ssZ\w-Zn\ Imcy-ß-fn¬ AXn-]-[m-\-amb ]¶v Cu
tÃj≥ \n¿h-ln-®p-sIm-≠n-cp-∂p. bmXm-k-abw Adn-bp-∂Xv apX¬
kn\n-am-Km-\-߃ tIƒ°p-∂-Xp-h-sc-bp≈ Hcp taJe. P\-߃ Cu
Xocp-am-\-Øn-s\-Xnsc i‡-amb ]t£m-`-߃ \S-Øn. CXn-s\-
Øp-S¿∂v ]gb ka-b-߃ ho≠pw ÿm]n-°p-Ibpw H∏w a[ym”
]t£-]-Whpw sIm≠p-h-cn-Ibpw sNbvXp. Aßs\ aqs∂-Æ-ambn
S≥kvan-j≥ ˛ ]`mXw, a-[ym-”w, kmbm-”w. tem°¬ Ãm‰kv
D≈ tÃj≥ aq∂v Sm≥kvan-j≥ \S-Øp-∂Xv C¥y-bn¬ Xs∂
A]q¿∆-am-Wv. IqSmsX sIm®n tÃj≥ AXns‚ ]h¿Ø-\-Ønse
]mK¤yw ]e-X-h-W-sX-fn-bn-®n- p-≠v. AJn-e- tI-cf tdUn-tbm- \mSI
a-’-c-Øn¬ ]e XhW tÃj≥ H∂mw ÿm\w \ne\n¿Øn. Ch¿
D≠m-°n-s°m-Sp-°p∂ dh\yq hcp-am\w ]cn-K-Wn-°p-tºmƒ D∂-Xm-
[n-Im-cn-Iƒ°v CXns‚ tem°¬ ]Z-hn-I-f™v IqSp-X¬ Ãm^p-I-
sfbpw C≥^m-kvsS-®dpw kmt¶-XnI anI-hp≈ ÃpUn-tbmbpw A\p-
h-Zn-°m-hp-∂-Xm-Wv. cmhnse 6.55 apX¬ 8.30 aWn-hsc ]t£-]Ww
sNøp∂ F^v.-Fw.-U-b-dn-bmWv Ch-cpsS hcp-am\ tkmX- v.- P-\-
ßsf Chcpambn G‰hpw IqSp-X¬ ASp-∏n-°p-∂-Xp-amb t]mKmw.
21
ae-bmf at\m-ca, k¨ Sn.-hn. _n ]n- F¬ XpS-ßnb am≤ya
`oa≥am-scms° tIc-f-Ønse ]apJ \K-c-ß-fn¬ F^v.- Fw.
tdUntbm ]t£-]Ww Bcw-`n-°p-∂-Xns‚ Hcp-°-߃ Ahkm\-
L-´Ønem-Wv. 2008 XpS-°-tØmsS Ch-cn¬ Nne-cpsS tÃj-\p-
IfpsS ]h¿Ø\w Bcw-`n-°pw.
kz¥w F^v.Fw tdUntbm kt‰-j-\p-I-fpsS ]Nm-c-W-Øn-
\mbn Xß-fpsS tÃj≥amXw e`n-°-Ø-°-hn-[-Øn¬ tÃj≥ tem-
°p- sNbvX(a‰v tÃj-\p-Iƒ Syq¨ sNbvXv e`n-°mØ hn[-Øn¬
tem°v sNb-X) F^v.-Fw. tdUn-tbm-Iƒ kuP-\y-ambn timXm-
°ƒ°v \¬Im≥ Ch-cnse Hcp ]apJ Iº\n Xøm-sd-Sp-°p-∂-Xmbn
clky tIµßfn¬ \n∂v Ce-IvtSm-WnIvkv tlm_o k¿Iyq-´n\v
hnhcw e`n®p. Cu kvIq∏v hmb-\-°m-cp-ambn ]¶p-sh-°p∂-Xn¬
BÀm-Z-ap-≠v. ssN\-bn¬\n∂v Cd-°p-a-Xn-sNbvX UnPn-‰¬ F^v.-
Fw.- td-UntbmIƒ Ct∏mƒXs∂ 30 cq] apX¬ hne°v Fd-Wm-Ip-
fØv e`n-°p-∂-Xn-\m¬ C°mcyw Nncn®v Xt≈≠ Imcy-an-√t√m!
FM Loop Antenna
24
lm^v thhv ssUt]mƒ aXn-bm-Ip-sa-∂-Xn-\m¬ 3.1 = ao‰¿
2
Cu \ofw hcp∂ Hcp 3/8 Aeq-an-\nbw ss]∏v FSpØv D≈n¬
aW¬ \nd®v km-h[m-\-Øn¬ hf-s®-Sp-°-Ww.
As√-¶n¬ Hcp ]´nI IjW-Øn¬ NnXØn¬ ImWp∂Xp
t]mse sSen-hn-j≥ B‚o\ IWIvSv sNøm≥ D]-tbm-Kn-°p∂
dn_¨ tI_nƒ ap≥]-d-™-\o-f-Øn¬ apdn®v BWn-b-Sn-®p-w Dd-∏n°mw.
IW-£≥ t]mbn-‚ v XmgvhiØv hcp∂ hn[-Øn¬ thWw
B‚n\ GI ss]∏v D]-tbm-Kn®v Db-c-Øn¬ Dd-∏n-t°-≠-Xm-Wv. CXn-
\mbn B‚n\ amkv‰n¬ GI ¢mºp-Iƒ GI ss]∏v Dd-∏n-°mw. eq∏v
B‚n-\-bn¬ \n∂v tdUn-tbm-bn-te°v dn_¨ tI_nƒ D]-tbm-Kn®v
IW-£≥ sImSp-°mw.
B‚n\bpsS s]mkn-k-j≥ hyXymkw hcpØn IqSp-X¬tÃ-
j-\p-I-fn¬ hy‡-ambn e`n-°p-∂ -Zn-i-bn¬ B‚n\ Dd-∏n-°p-I.
ssUt]mƒ B‚n\
ssUt]mƒ B‚n\ amXw D]-tbm-Kn-°p-∂-h¿ B‚n\ km[m-
cW ^n‰p-sN-øp∂ slmdn-tkm-≠¬ s]mkn-j-\n¬ \n∂pw hyXy-
ÿ-ambn sh¿´n-°¬ s]mfm-cn-‰n-bn¬ ^n‰p sNbvXp t\m°q. hfsc
hnZp-c-amb tÃj-\p-Iƒ \nß-fpsS tdUn-tbm-bn¬ e`n-°p-∂-Xp-Im-
Wmw. (F.M _qÃ-dp-Iƒ D]-tbm-Kn°Ww.) sh¿´n°¬ s]mfm-cn-‰n-
bn¬ 10 apX¬ 20 UnKn-hsc A¬∏m¬∏w Sn¬‰v sNbvXv ssUt∏mƒ
^n‰v sNøp∂Xv dnk-]vj≥ tImfn-‰n-Iq´pw
FM ^o¬Uv kvsSMvXv ao‰¿
hnZqc FM tÃj-\p-Iƒ Syq¨ sNøp-∂-Xn\v dxr am¿°v hfsc
klm-b-amb Hcp k¿Iyq-´mWv C\n sImSp-°p-∂-Xv. CXnse ao‰-
dmbn A\-temKv aƒ´n ao‰¿ 250 ssatIm Bºn-b¿ ske-£-\n-en´v
D]-tbm-Kn°mw
22
tdUntbm amt¶m FM tdUntbm
\µ-Ip-am¿
ae-bmf at\m-c-a-bpsS fm tdUntbm Nm\¬ tdUntbm amt¶m
91.9 saKm-sl-Uvkn¬ tImgn-t°mSv, IÆq¿, Xr»q¿, F∂nhnSßfn¬
]t£]Ww Bcw`n®p. tÃj\n¬\n∂v 50 Intem-ao-‰¿ Np‰-f-hn¬
CXns‚ ]t£-]Ww e`n°pw ^n©v Gcn-bm-bn¬ \n∂v Cu FMNm\¬ hy‡-ambn e`n-°p-∂-Xn-\p≈ B‚o-\m-bpsS \n¿ΩmW hnh-
c-߃ C\n -hn-h-cn-°p-∂p.
hnZpc]tZ-i-ß-fn¬ FM tÃj-\p-Iƒ hy‡-am-bn- e-`-n°p-
∂-Xn\v ]tXy-I-ambn Xøm-dm-°p∂ B‚o\-Iƒ hfsc ][m\ ]¶p-
h-ln-°p-∂p. GXv tÃjs‚bmtWm B‚o\ \ap°v \n¿Ωn-t°-≠Xv
B tÃ-js‚ ^oIz≥kn Adn-™n-cn-°Ww. AXn\v tijw Xmsg
sImSp-Øn-cn-°p∂ t^m¿ape A\p-k-cn®v B‚o\m ssUt]m-fns‚
\ofw I≠p-]n-Sn-°mw.
300(-tIm¨Ã‚ v) =ssUt]mƒ \ofw ao‰-dn¬
F (^o-Iz≥kn)
Ct∏mƒ In´p∂Xv Ce-IvSn-°¬ thhv seMvXv Bbn-cn-°pw.
AXns‚ 95% Bbn-cn°pw. ^nkn-°¬ seMvXv AYhm ssUt]m-
fns‚ bYm¿∞-Øn-ep≈ \ofw
DZm-lcWw sIm®n fm kt‰-j≥
^oIz≥kn =102.4 #nk tÃj≥
Ce-IvSn-°¬ thhv seMvXv =300 = 2.929 M
102.4 MHz
23
ssUt]m-fns‚ \ofw =2.929 % x 95% =2.782 meter
ChnsS e`n-®n-cn-°p-∂Xv pƒthhv ssUt]mƒ seMvXv BWv.
F∂m¬ FM e`n°phm≥ lmhv thhv ssUt]mƒ BsW-¶nepw
aXn.
At∏mƒ
lm^v thhv ssUt]m-fns‚ \ofw = 2.782 = 1.391 meter
ssUt]mƒ B°n FSp-°p-∂-Xn\v Syq_n\p≈n¬ aW¬
\nd®v hf-s®-Sp-°m-hp∂XmWv. ssUt]mƒ hf-s®-Sp-°p-∂Xv XΩn-
ep≈ AIew 3 As√-¶n¬ 4 C©v aXn-bmhpw. ssUt]m-fns‚ aeoUv `qan-bp-ambn hb¿sIm≠v _‘n-°-Ww. b eoUv tdUn-tbm-
bpsS sSen-kvtIm-∏n°v B‚n-\m-bn¬ sImSp-°p-I. ssUt]mƒ 10
meter Db-c-Øn¬ shbv°p-∂Xv hy‡-X-D-≠m-hm≥ klm-bn-°pw.
AXp-t]mse Ub-d-£≥Xn-cn®v SyqWnwKv hyXym-k-s∏-Sp-Øm-hp-∂-
Xm-Wv. CXvt]mse Xs∂ \ap°v tdUntbm amt¶m B‚n-\-bpsS
ssUt]mƒ \n¿Ωn-°mw.
300 .
91.9 MHz =3.26 meter
3.26 x 95% ˛ 3.1 meter
25
]m¿´v enÃv
tr-1 c 2570/2n918 c1 - 56 pf
d1-d2 in 60 c2,c3,c4,1kp
r1-r5 220 em-250 ssatIm-Bºv ao‰¿
r1- 270
r2 -47 k
r3-1k5 - r4 180 r.vr1 4k7 ]osk‰v
FM. Boosterhfsc ho°mb FM kn·-ep-Iƒ Hcp sNdnb ssl^o-
Iz≥kn ]o Bwπn-^-b¿ D]-tbm-Kn®v _qÃv sNbvXm¬ amXsa
hy‡-ambn \ap°v ihn-°m≥ km[yamIq. CXn\v D]-tbm-Kn-°m-
hp∂ hfsc efn-X-amS k¿Iyq-´mWv ChnsS sImSp-Øn-cn-°p-∂Xv
Cu k¿Iyq-´ns‚ Pcb te Hu´pw H∏w \¬In-bn-cn-°p-∂Xv. sk¬^v
I¨kvSIv‰¿ am¿°v hfsc ]tbm-P\ ]Z-am-bn-cn°pw
28
Wv. c≠m-asØ am¿§-Øn¬ ]t£-]Ww sNtø≠ HmUntbm
^oIz≥kn-bpsS Bπn-‰yq-Un-ep-≠m-Ip∂ am‰-߃°-\pkrXambn
am‰w Icn-b¿ ^oIz≥kn-bpsS ^oIz≥kn-bn-ep-≠m-Ip-∂p. CØcw
tamUp-te-js\ ^oIz≥kn tamUn-te-j≥ AYhm FM F∂p-hn-fn-
°p-∂p.
FM Sm≥kvan-j≥ D]-tbm-Kn-°p-tºmƒ G‰hpw IqSp-X¬ knKn-
\¬ Sp t\mbvkv tdtjym (SNR) km[y-am-Wv F∂-Xn-\m¬ a‰v i_vZ-
ß-sfm∂pw CS-bn¬ IS-°msX hfsc sXfn™ iw_vZw e`n-°pw
F∂-XmWv G‰hpw henb ]tXy-IX.
sSen-hn-j≥ ]nIvN¿ sSen-ImÃv sNøp-hm≥ Bπn-‰yqUv tamUp-
te-j\pw i_vZw ]t£-]n-°m≥ ^oIz≥kn tamUp-te-j-\p-am-Wv
D]-tbm-Kn-°p-∂-sX-∂p-IqSn Hm¿°p-a-t√m.
bqtdm-∏nepw Ata-cn-°-bnepw C¥y-bnepw FM t_mUv
Imkvddv _m≥Uv 88 MHZ to108 MHZ -B-Wv.
Ãocntbm FM B‚n\
26
]m¿´v enÃv
c1 5pf ,c2, 12 pf c,3,12pf
c4.01
vci,vc2 22pf trimmer
ri 33k
r2 330 r
r3
1k5
L1 tImbn¬ 4Np-‰p-Iƒ 22 sws C≥kp-te-‰Uv tIm∏¿ hb¿
D]-tbm-Kn®v 5 mm Ub-ao-‰¿ (sP¬ t]\-bpsS hÆ-ap≈ do^n-√ns‚
]pdsa Np‰n-sb-Sp-°mw.)
F¿Øv sskUn¬ \n∂v H∂m-asØ Np‰ns‚ apIƒ `mKØv
A¬∏w C≥kp-te-j≥ If™v AhnsS \n∂pw Sm∏nßv FSp°mw
27
tImbn¬ L2.22 tKPv C≥kp-te-‰Uv tIm∏¿ hb¿ D]-tbm-
Kn®v 3 Np‰p-Iƒ 5 mm Ub-ao-‰-¿ B‚n\ C≥ ]p´n\pw Hu´v ]p´n\pw
A\p-tbm-Py-amb tkm°-‰p-Iƒ D]-tbm-Kn-°p-I. _qÃ-dn-\p≈ ]h¿
ksπ \√ hÆw ^n¬‰¿ sNbvX sdKp-te-‰Uv dc Bbn-cn-°p-∂Xv
DØ-a-am-bn-cn-°pw. 12 thmƒ´v UPS _m‰-dnbpw D]-tbm-Kn°mw.
(k¿Iyq-´v)
hnj-a-Xbpw CØcw ]t£-]-W-Øn¬ IqSpw. AXn-\m¬
HmUntbm ^oIz≥kn t\cn´p ]t£-]-W-Ø\v D]-tbm-Kn-°msX
AXn¬ \n∂pw Db¿∂ Hcp ^oIz≥kn-bp-ambn Ie¿Øn ]t£-
]Ww sNøp-I-bm-Wv ]Xnhv.
Cßs\ Ie¿Øm≥ As√-¶n¬ s]mXn-bm-\mbn D]-tbm-
Kn-°p∂ ^oIz≥knsb Imcn-b¿ ^oIz≥kn (carrier frequency) As√-
¶n¬ tdUntbm ^oIz≥kn (rf) F∂p hnfn-°p-∂p. Hcp tdUn-tbm-
tÃ-js‚ ^oIz≥kn Cu Icn-b¿ ^oIz≥kn Bbn-cn-°pw.
Icn-b¿ ^oIz≥kn°v Bπn-‰yqUv (amplitude) ^oIz≥kn
(freequenct) F∂nh at‰-sXmcp ^oIz≥kn-°p-ap-≈-Xp-t]mseXs∂
D≠m-bn-cn°pw. ]t£-]Ww sNtø≠ HmUn-tbm-^o-Iz≥kn-bpsS
Bwπn-‰yq-Unt\m ^oIz≥kn-°p-≈Xp t]mse Xs∂ D≠m-bn-cn°pw.
]t£-]Ww sNtø≠ HmUntbm ^oIz≥kn-bpsS Bπn-‰yq-Unt\m
^oIz≥knt°m A\p-kr-X-ambn Imcn-b¿ ^oIz≥kn°v am‰w hcp-
Øns°m≠mWv Cu Ie¿Ø¬ AYhm s]mXnb¬ \S-°p-∂-Xv.
Cu ]In-bsb tamUp-te-j≥ F∂p hnfn-°p-∂p. CXv c≠v Xc-Ø-
ep-≠v. (1)
(1) Bπn-‰yqUv tamUp-te-j≥ (A.M) (2) ^oIz≥kn tamUp-te-j≥
(F.M) ]t£]Ww sNtø≠ HmUntbm ^oIz≥kn-bpsS Bwπn-
‰yqUn¬ D≠m-Ip∂ am‰-߃°-\p-krX-ambn Imcn-b¿ ^oIz≥kn-
bpsS Bπn-‰yq-Unepw am‰-ß-fp-≠m-Ip∂ Xc-Øn-ep≈ tamUp-te-
js\ bmWv Bπn-‰yqUv tamUp-te-j≥ AYhm (A.M) F∂p hnfn-°p-
∂-Xv. Ct∏mƒ k¿∆ km[m-c-W-amb tamUp-te-j≥ am¿§w CXm-
29
A¬∏w Nne-th-dp-sa-¶nepw FM tÃj-\n¬ \n∂pw Ipd-®p-
IqSn AI∂ ÿe-ß-fn¬t∏mepw FM ]cn-]m-Sn-Iƒ kzoI-cn-°p-∂-
Xn\v km[y-am-Ip∂ Hcp B‚n-\-bm-WnXv. IqSmsX FM Ãocntbm
kzoI-c-W-Øn\v th≠n Unssk≥ sNø-s∏-´n-cn-°p∂ Cu B‚n\
`mhn-bnse kwKo-Xm-kzm-Z-\-Øn\v Hcp klmbn Bbncn-°pw. ]co-
£-W-sa∂ \nebv°v CXv \n¿Ωn-®m¬ \nß-fpsS ÿe-Øn-\-SptØm
Aev∏w AI-etbm D≈ Ãocntbm FM tÃj≥ kzoI-cn-°m≥ Ign-
t™-°mw.
FSpØp ]d-tb≠ as‰mcp ]tXy-IX Cu B‚n\ GsX-
¶nepw Hcp ]tXyI FM kvt‰j≥ amXw kzoI-cn-°m≥ kwhn-[m\w
sNø-s∏-´n-´p-≈-X√ F∂-Xm-Wv. FM _m‚nse 88 MHz apX¬ 108 MHzhscbp≈ ]q¿Æ-amb ^oIz≥kn-Iƒ kzoI-cn-°m≥ th≠n
Unssk≥ sNbvX-Xn-\m¬ FM _m‚nse GXv tÃj≥ kzoI-cn-
°m\pw CXp aXn-bmIpw FM, B‚n-\-I-fnepw TV B‚n-\-I-fnepap]-
tbm-Kn-°p∂ Aeq-an-\nbw Ipg¬ Cu B‚n\ \n¿Ωn-°p-∂-Xn\v Bh-
iy-an√. (C-Øcw IpgepIƒ hf-bv°p-∂-Xn\pw apdn-°p-∂-Xn\psa√mw
_p≤n-ap-´p≈ tPmen-bm-W-t√m.?) ]I-c-ambn ]e-I-°-jW-Øn¬
kvIqsN-bvXp-d-∏n-®n-´p≈ I´n-bp≈ Aeq-an-\nbw t^mbn¬ BWv
Fen-sa‚p-I-fmbn ]h¿Øn-∏n-°p-∂-Xv. Cu Fen-sa‚p-Isf XΩn¬
_‘n-∏-°m≥ 18 tKPv Aeq-an-\nbw Iºnbpw D]-tbm-Kn-°p-∂p.
\n¿ΩmWw
H≥]-XcbSn \ofhpw c≠n©p hoXnbpw H-cn©p I\-hp-ap≈
aq∂p ]e-I-°-j-W-ß-fn¬ thWw Aeq-an-\nbw t^mbn¬ Dd-∏n-
°m≥ (]-eI °jvW-ß-fpsS hen∏w tI´v A¤p-X-s∏-tS-≠, -C-
X¬∏w henb B‚n\ Xs∂-bm-Wv. HmSn´ hoSp-I-fn¬ HmSp ]mIm≥
th≠n Igp-t°m-en¬ Xd-°p∂ ]´nI As√-¶n¬ ]´n-tbm¬ CXn\p
th≠n D]-tbm-Kn-°mw. GsX-¶nepw ]mgv XSn-bpsS ]´nI Bbmepw
aXn. CuSp \n¬°-W-sa-¶n¬ \√ XSn D]-tbm-Kn-°p-Itbm s]bn‚p
sNbvXv kwc-£n-°pItbm thW-sa∂p amXw.
32
FM ReceiversFrequency modulation is used in radio broadcast in the bandwidth
range from 88 MHz til 108 MHz. This range is being marked as “FM” on theband scales of the radio receivers, and the devices that are able to receivesuch signals are called the FM receivers.
Radio broadcast transmitters are using the amplitude modulationon LW, MW and SW bandwidths. According to international treaties, eachof the transmitters has a 9 kHz wide broadcasting channel, therefore mak-ing maximum frequency of the information being transferred fNFmax=4.5kHz, according to the characteristics of the AM signal. To put it more simple,the highest frequency of the sound that can be heard from the loudspeakerof an AM receiver is 4.5 kHz, all above it will be simply truncated in thecircuitry. Considering the speech itself, this isn’t so important since themost important components are located below these 4.5 kHz (during thetelephone transfer, all the components above 3.2 kHz are being cut, andnobody is complaining). Things stand different, however, for the transfer ofmusic. Music has much more sound components, with their frequenciesspreading up to 15 kHz, so truncating them above 4.5 kHz does deterioratethe transmission quality.
The radio-broadcast FM transmitter has a 250 kHz wide channel onits disposal, therefore allowing for the maximum frequency of the informa-tion (acc. to the characteristics of the FM signal) to be fNFmax=15 kHz.That means that music is being fully transferred and its quality is signifi-cantly better than in the case of the AM transfer. The FM transfer has someother advantages, perhaps the most significant of them being the possibilityof eliminating various disturbances that are manifesting themselves as snap-ping, squeaking etc. The main disadvantage, however, is not the result ofthe frequency modulation itself, but rather of the fact that this method isbeing used on high frequencies, and that high-frequency electromagneticwaves behave themself as light, spreading themselves in straight line, notreflecting from the ionosphere etc. This is why obtaining this kind of radio-link requires optical visibility between the transmission and reception an-tennas, which is not the case for the links obtained on frequencies which
30
Aeq-an-\nbw t^mbn¬ Ac C©p hoXnbpw 54 C©v
\ofhpap≈Xv Bdp IjWw thWw. Hmtcm ]´n-I-bnepw c≠p-IjWw
hoX-amWv Dd-∏n-t°-≠-Xv. ]´n-I-bpsS HØ-a-≤y-Øn¬ Hmtcm C©v
AI-e-Øn¬ Ch Aeq-an-\nbw As√-¶n¬ _mkv kvIq D]-tbm-
Kn®v Dd-∏n-°pI. At∏mƒ Hcp-]- n-I-bnse c≠v Aeq-an-\nbw t^mbn¬
IjW-߃ XΩn¬ 2 C©v AI-e-߃ D≠m-bn-cn-°pw. 54 C©p
\of-ap≈ t^mbn-ep-Iƒ°v tijw ]´n-I-bpsS c≠-‰Øpw aq∂v C©v
hoXw shdpsX InS-°pw. Cßs\ aqs∂Æw Xøm-dm-°p-I.
]Xn-\m-dSn \of-ap≈ Hcp Aeq-an-\nbw Ipg¬ FSpØv CXn¬
Xøm-dm°n sh®n-cn-°p∂ aq∂v Fen-sa‚p-Ifpw U ¢mºv D]-tbm-Kn®v
Dd-∏n-°p-I. Hc-‰-Ømbn BZysØ Fen-sa‚ v Dd-∏n® tijw B Fen-
sa‚nse Aeq-an-\nbw t^mbn¬ \n∂pw IrXyw 64 C©v AI-e-
Øn¬ c≠m-asØ Fen-sa‚nse Aeq-an-\nbw t^mbn¬ hc-Ø-°-
hn[w c≠m-a-ØXpw ¢mºp-]-tbm-Kn®v Dd-∏n-°p-I. CXp t]mse Xs∂
c≠pw aq∂pw Fen-sa‚p-Iƒ XΩn¬ IrXyw 64 C©v AIew kq£n-
®p-sIm-≠v aq∂m-asØ Fen-sa‚pw ¢mºw sNøpI.
XpS¿∂v aq∂v Fen-sa‚p-Ifpw XΩn¬ XΩn¬ Aeq-an-\nbw
Iºn-sIm≠v C\n ]d-bp-∂-Xp-t]mse _‘n-∏n-°-Ww. BZysØ Fen-
sa‚n¬ c≠n-©-I-e-Øn¬ c≠v Aeq-an-\nbw t^mbn¬ IjW-߃
Dd-∏n-®n-´p-≠t√m? CXn¬ H-sc-Æ-Øns‚ AK-Øn¬ D≈ kvIq
A¬∏-ambn Ab-®n´v AXn¬ 18 tKPv Aeq-an-\nbw Iºn-bpsS Hc‰w
Np‰n-bn´v B kvIq ho≠pw Dd-∏n-°p-I. NnX-Øn¬ ImWp-∂-Xp-
t]mse Aeq-an-\nbw Iºn c≠m-asØ Fen-sa‚nse heXp hi-
Øp≈ t^mbn-enepw XpS¿∂v aq∂m-asØ Fen-sa‚nse CS-Xp-h-i-
Øp≈ t^mbn-enepw _‘n-∏n-°p-I. _m°n Iºn 40 C©p \of-
Øn¬ U BIr-Xn-bn¬ hf®v aq∂m-asØ Fen-sa‚ns‚ Iºn IWIvSp
sNømØ t^mbnen¬ IW-IvSp-sN-øp-I. XpS¿∂v 2,1 F∂ Fen-
sa‚nse Iºn IWIvSp sNømØ t^mbn-ep-I-fn¬ IqSn IW-
IvSpsNbvXp Iºn-bpsS IW-£≥ Ah-km-\n-∏n-°mw. Ct∏mƒ 1, 2
F∂o Fen-sa‚p-I-fpsS CSbv°pw c≠v aq∂v F∂o Fen-sa‚p-I-
31
fpsS CSbv°pw Iºn H∂n\p aosX H∂mbn tImkv sNøp-∂p≠v
Cu tImkn-ßn¬ Iºn XΩn¬ kv]¿in-°msX t\m°-Ww. AXp-
t]mse Xs∂ Fen-sa‚p-Iƒ Dd-∏n-®n-cn-°p∂ Aeq-an-\nbw Ipg-enepw
Iºn kv]¿in-°-cp-Xv.
Cu B‚n-\-bn¬ \n∂pw FM tdUn-tbm-bn-te°p≈ IW-
£≥ eoUn\v Hcp 300 dn_¨ tI_nƒ D]-tbm-Kn-°-Ww. TV B‚n-
\-bn¬ \n∂pw TV bnte°v IWIvSp sNøp∂ AtX tI_nƒ Xs∂.
CXv B‚n-\-bpsS U t]mse hf® `mKØv hf™ `mK-Øp-\n∂pw
]¥-≠n©v AIsebmbn (A-s√-¶n¬ aq∂m-asØ Fen-sa‚n¬
\n∂pw 28 C©v AI-e-Øn¬ thWw IWIvSv sNøm≥. tI_n-fns‚
at‰ AKw tdUn-tbm-bpsS FM B‚n\m sS¿Ωn\-en¬ \¬Ip-I.
]m¿´v enÃv
(]-´n-I-I-jvW-߃ ) H∂Xc ASn \ofw, c≠n©v hoXn. -3 FÆw
Aeq-an-\nbw hb¿ Aeq-an-\nbw Ipg¬ kIq-Iƒ XpS-ßn-bh.
(Aeqan\nbw t^mbn¬ ]gb I∏mkn‰dpIfn¬ \n∂v e`n°pw)
33
are less than 40 MHz. In practical terms, it is possible to receive the SWsignal from anywhere on Earth, whilst the range of an UHF link is limited tothe horizon. Or, as Hamlet would say: “The quality or the range, that is thequestion!”
Can we have it both, somehow? Yes we can, and it is alreadybeing done, over the satellite links, using the same equipment as for the TVsignal receipt and an audio amplifier connected to the audio output of thesatellite receiver. For now, in the earthly conditions, those that are inter-ested in the worldwide news will make and use the AM receivers, and mu-sic lovers will stick to the FM’s. And what can those interested in both do?Well, they make AM-FM receivers :)
The direct-type (TRF) FM receivers have never been produced, theindustry started right away with the superheterodynes,In amateur life, how-ever, the direct FM receivers do exist, having very simple electronic dia-grams and being easy to manufacture. These receivers have very strongpositive feedback, making the intermittent oscillations in it, and are there-fore being called the super-reaction receivers.
The Simplest FM ReceiverOn Pic.3.43 you can se the electronic circuit of an extremely simple
direct FM receiver. The T2 transistor together with the R1 resistor, the coilL the variable capacitor C and internal capacitances of the T1 transistor,comprises the so-called Kolpitz oscillator. The resonance frequency of thisoscillator is being set by C to correspond to the one of the station that wewish to hear (meaning it has to be altered between 88 and 108 MHz). Thesignal, i.e. the information being used in the transmitter to perform themodulation, is extracted on the R1 resistor, and being led from it to thehigh-resistance headphones, over the coupling capacitor C1.
36
FM Receiver with one Transistor and Audio Amplifier
We have made this receiver on the experimental plate, and it wasplaying for days in our lab. Its electronic diagram is given on Pic.3.46.Regretfully we had to disassemble it, since we needed the plate for one ofthe devices described later in this book. This, too, is a reaction-type receiver,where the BF256 transistor, coil L and capacitors C, C* and C2 form theHartley oscillator. Its frequency is being adjusted by means of the variablecapacitor C to be equal to the frequency of the station that we wish to listento. The LF signal is being taken from the R1 resistor, and led into the audioamplifier.
* The coil L is self-supporting (doesn’t have the body), made of 5quirks of CuL wire, its diameter being from 0.8 to 1 mm. It is spooled onsome cylindrical object (pencil, pen etc., the best thing is the round part ofa 9 mm drill), in one layer, quirks put tight to each other, as shown in theleft, framed part of the picture. When the coil is finished, it is taken off thecylinder and stretched a little, so that the quirks do not touch each other. Itsfinal length should be about 10 mm. The mid coil leg, which is to be connected
34
* The capacitance of the variable capacitor should be able to changefrom a couple of pF (Cmin) to app. 20 pF. During the testing off this device,we were using the capacitor from Pic.3.8. The legs marked as FO and Gwere used, the G leg being connected to the ground. When all the trimmersfrom the circuit on the Pic.3.8 are set to minimum capacitance, thecapacitance between the FO and G legs should be adjustable between 7and 27 pF.
* The coil L has 4 quirks of lacquer-isolated copper wire (CuL),bended to have a 4 mm internal diameter. The practical realization of thiscoil is explained in text connected with Pic.4.9. During the setup of thebandwidth, the inductance of the coil can be altered by changing the distancebetween the quirks. If the coil is stretched the inductance decreases, andvice versa. If this cannot give the desired results, new coil must be made.
* The telescopic antenna taken from a disused device can be used.If you can’t find one, you obtain very good results with a piece of isolatedcopper wire, about 60 cm long (the optimum length to be foundexperimentally).
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The Simplest FM Receiver with Audio AmplifierThe radio-broadcast FM transmitters operate with output power
that is much smaller than that of the AM transmitters. That is why the LFsignal coming from the device on Pic.3.43 is rather small, urging the use ofvery sensitive headphones. They are much more expensive than the“ordinary” ones, making it better to use the cheap headphones in connectionwith audio amplifier. One such solution where TDA7050 IC is used is givenon the Pic.3.44. The R3 resistor and capacitors C5 and C6 are to be addedonly if the operation of the device is unstable. There optimum values are tobe found experimentally, starting with those shown in the picture.
For loudspeaker reproduction any of the previously describedamplifiers can be used, e.g. that from Pic.3.21 (which we have been using,very successfully), or one of the devices described in P.E.4 and P.E.5.Since in these amplifiers a battery with voltage bigger than 3 V is used,using of R3 and C5 is obligatory. The R3 is counted from the formula whereUBAT is battery voltage, and 0.235 mA is the current through R1, thatsupplies T1 and T2. E.g. if UBAT=9 V, it is then and the nearest existingresistor is used.
Capacitors C5 and C6 comprise, together with R3, a pass-filter forvery low frequencies, which is used to separate the HF and LF parts of thereceiver.
The battery itself acts as a short-circuit for the AC currents. Butwhen it ages its resistance increases and there is no more short-circuit.That is why C3 and C4 are added, to accomplish it.
37
to the left end of the C3 capacitor, is made by taking off couple of millimetresof the lacquer from the wire, approximately in the middle of the coil. Thisplace is then tinned and a piece of thin wire is soldered to it. The other endof this wire is soldered onto the PCB, on its place, to be connected to theleft end of C2.
* For the variable capacitor C the one from the Pic.3.8 (legs FOand G, G goes to Gnd). If you are using some other capacitor, that hasbigger capacitance, and you cannot achieve the reception of the full FMbandwidth (88 til 108 MHz), try changing the value of the C*. Its capacitanceis to be determined experimentally, usually being about a dozen pF.
* HFC is the high-frequency choke. Together with C2, it makes afilter that prevents the HF current to flow through the R1, simultaneouslyallowing for DC and LF current to go through. The muffler is, in fact, a coilthat has 16 quirks of 0.6 mm CuL wire, spooled on a round part of a 3 mmdrill.
* This receiver works well even without the external antenna. It can,of course, be connected to it, as shown in dashed line. Instead of antenna,a 50 mm piece of wire can also be used.
FM Receiver with (just) one TransistorOn the left side of the Pic.3.46 you can see the diagram of another
very simple FM receiver, that has only one transistor as the active element.That is, as one can see, the HF part of the receiver from Pic.3.45, where
40
the oscillator, accomplish the reception of AM stations from all the bandwidthsfrom 70 kHz till 200 MHz.
Superheterodyne FM ReceiversThe FM receivers being described in chapter 3.15 are the amateur
solutions. These are extremely simple devices, that cannot perform thenoiseless tuning, automatic oscillator frequency regulation and other featuresthat ensure very high quality of the reproduction, being expected from anUHF FM receiver. The true solution is the superheterodyne FM receiver,whose block-diagram is given on Pic.4.6.Station signals are taken from thedipole antenna and led through the appropriate cable into the input circuit(UK). Inside it, the signal selection is performed, of station whose frequencyis fS, this signal is then amplified in the HF amplifier and led into the mixer.As in the case of earlier described AM receiver, the inter-frequency signal isobtained at the mixer output, whose carrier frequency is fm=10.7 MHz (thisis the standard value, used in all radio-broadcast FM receivers). The IFsignal is being amplified in the IF amplifier and led on the amplitude limiter(Ogr.). In this stage the signal whose amplitude exceeds certain level isbeing cut off, accomplishing with this the elimination of the parasite amplitudemodulation, which is performed by various noise sources during thetransmission (atmospheric charges, various electrical devices etc.), whichsignificantly improves the signal quality. The signal then goes to the FMsignal detector, where the information being modulated in the transmitter isextrapolated from the signal, followed by the LF part of the receiver. WithAFC the circuit that performs the automatic frequency regulation of thelocal oscillator is labelled
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the reproduction is being accomplished over the high-resistance headphones.But, as previously noticed, they are pretty expensive, therefore making itbetter to use the “regular” headphones and a simple amplifier, as shown onthe right side of the Pic.3.46.
The Fully (not exactly 100%) SuperheterodyneAM Receiver No.1
Its electrical diagram is given on Pic.4.4. It is easily being noticedthat this is the receiver from Pic.4.2 with inter-frequency (IF) amplifier withZN415E added. By adding ZN415 IC multiple enhancements are performed.Thanks to its huge input resistance, the MFT’s oscillatory circuit is not choked,resulting in better selectivity. The sensitivity of the device is extremelyincreased since this IC has big amplification and the AAR (automaticamplification regulation) is also accomplished, making the usage of this deviceeasier and more comfortable.* It is very important to obtain the necessaryvalue of the DC voltage in pin 6 of the ZN415 for its proper operation. Acc. tothe table on Pic.3.36 it has to be about 1.3 V, and its setting is done via theTP1 trimmer. The receiver is set to some weaker station, the sound volumeis made very low with potentiometer P, and the slider of the TP1 is carefullymoved until the best reception is made. If that doesn’t work, one should trychanging the value of R5 resistor; this is to be done also if the supply voltagebeing used is other than 12 V. In case of voltage on the pin being muchbigger than 1.3 V, and cannot be reduced on the trimmer, short-circuit one ofthe diodes.* The voltage stabilizer with 78L06 isn’t needed if the receiver issupplied from the 6 V battery.* The receiver from Pic.4.2 needs input circuitto be 100% complete. That can be an independent input circuit from Pic.4.3-i, or input circuit and the HF amplifier that are described in the Appendix(Pic.5.10). If the former circuit is used, station tuning is being accomplishedwith 2 knobs, as explained in the previous chapter.
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Fully (not exactly 100%) Superheterodyne AMReceiver No.2
All the receivers we made with NE612 IC were tested in our lab,except the one from the previous project, since we didn’t have ZN415 “withus”. We found, however, a ZN414 IC, so we tested the receiver from Pic.4.5with it. The receiver was working great, from the amateur’s point of view. Heplayed us for long time, until we didn’t require the board to test one of thereceivers from previous projects afterwards, when we regretfully had todisassemble it. * The diagram is very similar to that on Pic.4.4, so most ofthe things said about that receivers stands for this one, too.* DC voltagesetting on pin 1 of ZN414 is done with the trimmer TP. Its slider is put in midposition, the receiver is tuned to some weaker station close to the upperbound of the bandwidth. While making the reproduction very quiet (slider ofP as low as possible), the trimmer slider is moved until reaching optimumreception. After that the trimmer is disconnected, its resistance measuredand the ordinary resistor of similar value is put into circuit. * The deviceoperates nicely with the outside antenna made of a piece of wire measuringonly half metres in length.* The reception would certainly become better ifan input circuit would be added, which we spoke about in the previousproject.* The receivers from pics. 4.4 and 4.5 can, with appropriate coils in
4144
capacitance of Cs should be reduced (to 15 pF, 10 pF etc.), or it should beshort-circuited. You can also try compressing or stretching the L1 coil, etc.The setup of the oscillatory circuit is completed when with C=Cmax somestation that operates on app. 88 MHz can be heard, and with C=Cmin theone that works on 108 MHz. The input circuit setup (it is connected betweenpins 13 and 14), is performed by tuning the receiver to some mid-rangestation (about 98 MHz). Then, the best possible reception is searched, bychanging capacitances C13 and C12 and inductance L2.
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FM Receiver with TDA7000The face that FM receivers operate on pretty high frequencies makes
their practical realization somewhat difficult, but most of the problems, as inmany other amateur builds, originates from building the coils, except theself-bearing, small-inductance coils (without the coil body), which are easyto make, especially if there aren’t many of them in the device and if nospecial instruments are required for setting up their proper inductance value.The coils used in this FM receiver are just like this, and there are only twoof them, making the practical realization much easier.The basic data aboutthe famous Philips’ IC used in this project, TDA7000, are given in the followingtable.
Electronic diagram of the HF part of the device (from antenna to the LFoutput) built with TDA7000 is shown on Pic.4.7. As one can see, it is asimple device, made with relatively small number of components. The ICcontains all the stages of the superheterodine receiver: the mixer, theoscillator, the IF amplifier, the amplitude limiter, the FM detector and fewothers. More about them will be told in the next project which contains thedescription for a receiver with TDA7088T IC, which is the improved version ofTDA7000.The station signal is from the (telescopic) antenna led to the inputcircuit that consists of L2, C13, C12 and C14. It is a parallel oscillatorycircuit damped with R3 resistor, which has the reception bandwidth from 88MHz till 108 MHz (it admits all the UHF signals on the pin 13, and weakenste signals outside the reception bandwidth). Inside the IC the signals are ledinto the mixer, where they are being given new carrier frequencies. The IFamplifier then follows, amplifying only one of those signals, the one whosefrequency is equal to the inter-frequency, followed by the limiter, the FMdetector, mute circuit and LF pre-amplifier. The output from the last stage ison the pin 2 (R2 is the collector load of the last transistor in the LF pre-amplifier). The oscillatory circuit of the local oscillator (L1, Cp, Cs, C andC5) is connected between pins 5 and 6.Pic.4.8-a shows the PCB of thedevice from Pic.4.7, while Pic.4.8-b contains the component layout (on thePCB). The complete device can be seen on Pic.4.8-c. The variable capacitorfrom Pic.3.8 is used as the only variable capacitor here since the inputcircuit is aperiodic, the legs marked with FO and G. This capacitor servesus to tune the receiver to stations. In the LF part of the receiver, the amplifier
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made with LM386 from Pic.3.19 is utilized (the components left from thepotentiometer are omitted).* L1 and L2 are the self-bearing coils (withoutthe core). They have few quirks and are made of relatively thick wire, thereforethey don’t need a body of any kind, that is why they are called “self-bearing”.Their appearance is shown on Pic.4.9, and the calculus for them is doneacc. to the table from Pic.3.5. They both have 6 quirks of the CuL wire, 0.6mm in diameter, being spooled on the flat part of the 3 mm drill. In order tobe able to solder the coil onto the PCB, the couple of mm of isolation hasto be removed from the wire ends with sharp knife, and they have to betinned afterwards. There must be a small gap between the adjacent quirks.The inductance of the coil is set by its shrinking (the inductance increases)or stretching (the inductance decreases). Stretching can be nicely done byinserting the screwdriver between the quirks and then turning it along thecoil. * The TDA7000 also contains the mute circuit (for noiseless tuning). Itis being active when the S2 switch is open. Pocket-type receivers usuallydo not have S2 and R1 elements.* The part of the receiver that requiresbiggest care during build is the oscillatory circuit of the local oscillator,which is connected between the pins 5 and 6. When changing thecapacitance of C, its resonance frequency must change from 88 MHz(C=Cmax) till 108 MHz (C=Cmin). If that cannot be accomplished (not allthe stations can be heard) some experimenting is required with capacitancesof Cp and Cs. For start, you should omit the Cp. If the problem persists,
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FM Receiver with TDA7088T IC
The receiver described in the last project has two IC’s, one variablecapacitor, two small coils and fairly small few other components, so it canbe put into some small box, by carefully placing the components. Furtherminiaturization can be accomplished by using the SMD components. Theseare the resistors, capacitors, transistors, IC’s and other components, whosedimensions are significantly smaller than these of “classical” components.They are mounted on the copper side of the PCB, therefore it isn’t necessaryto drill the holes on the board. TDA7088T is also an SMD component. Itsdrawing is shown on Pic.4.10.This IC is the successor of the famousTDA7000, i.e. it is an improved model of TDA7000, that allows to implementboth monophonic and stereophonic FM receiver.
The electronic diagram of the HF part of the monophonic FM receivermade with TDA7088T IC is given on Pic.4.11. The IC contains all the partsof the classic superheterodyne receiver: the local oscillator, IF amplifierand FM detector, but also some other circuits that extend the possibilitiesand improve the features of this IC.As far as practical use is concerned, themost significant novelty is the auto-tuning circuitry. No variable capacitor is
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TerminologyGain: amplification of the antenna (measured in dB)
dB: hey - if you don’t know this you are in the wrong article - butdivide it by 3 for small numbers and this gives you the multiplcationfactor for the signal
Attenuation: loss of the antenna or other component (measured indB)
Polar Pattern: a “map” of the antenna’s sensitivity, as viewed fromabove. Polar patterns given here should be used as reference guides- the area enclosed by the line corresponds to a geographic areaaround the antenna. The size of that area differs depending onantenna gain, the height of the antenna, and the geography of theterrain.
Beamwidth: angle of directions for which the antenna is mostsensitive
Adjacent channel / frequencies: FM frequencies occur on odd 200kHz multiples, starting at 88.1 MHz and ending at 107.9 MHz. Anadjacent channel (or frequency) is one 200 kHz away.
Omnidirectional AntennasThose listeners that find themselves in the middle of a metropolitan
area, or very near to several nearby cities up to 30 or 40 miles away canbenefit mostly from an omnidirectional antenna. This type of antenna will beof no help, however, if you are trying to receive a more distant, low power, ortranslator station. For these type of stations, a good directional antenna willbe needed.
Omnidirectional antennas come in two types: The “S” curve typeand the “turnstile” type, shown below, along with their polar patterns. In thecase of the omnidirectional antennas, the very name implies “from alldirections eqaully”. The two antenna types have roughly circular polar
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necessary for tuning, as it was in all the previous projects, the BB910 varicapdiode is used instead. Its capacitance is being changed by varying the DCvoltage supplied to its anode over the 5k6 resistor. This is how the tuning isperformed: When the user press and releases the pushbutton marked with“RUN”, the positive voltage impulse is released to the S(et) input of theSEARCH TUNING circuit. The 100 nF capacitor then starts chargingl andthe voltage on the pin 16 increases. This voltage is then transferred, over the5k6, to the anode of the BB910, causing its capacitance to decrease, whichincreases the frequency of the local oscillator (VCO). The VCO voltage isled into the mixer (MIXER) which also receives, over pin 11, the signals of allthe other FM stations. The mixer outputs the FM signals whose frequenciesare equal to the differences of the oscillator and the original station frequency.The only signal that can reach the demodulator (FM detector) is the onewhose carrier frequency is equal to the inter-frequency, i.e. fm=73 kHz(selectivity is being accomplished by two active filters whose componentsare the capacitors connected to pins 6, 7, 8, 9 and 10). Therefore, theoscillator frequency increases until it gets the condition fO-fS=73 kHz isaccomplished. When this happens, the charging of the capacitor is haltedby the command that is sent into the SEARCH TUNING circuit by twodetectors (diode-blocks) located in the MUTE circuit. The AFC (AutomaticFrequency Control) circuit now gets its role and prevents the voltage on pin16 to be changed, until the RUN button is pushed again (this voltage canvary from 0 V til 1.8 V during the tuning). When the RESET button is pushed,the 100 nF capacitor is discharged, the voltage on pin 16 drops down tozero, and the receiver is set to the low end of the reception bandwidth, i.e.88 MHz.Let us get back to the mixer. On its output, the 73 kHz FM signalis obtained, and it is modulated by the programme of the first station that isfound after the RUN button is pushed. This signal then passes the activefilters, gets amplified in the IF amplifier (IF LIMITER) and passed onto theinput of the demodulator. By connecting the demodulator exit, over the LOOPFILTER, the adder (+) and resistor, to the VCO, the so-called FFL (FrequencyFeedback Loop) circuit is accomplished, reducing the deviations of the signalbeing received from ±75 kHz to ±15 kHz.The LF (AF) signal is led from thedemodulator, over the LOOP FILTER stage, the invertor (-1) and MUTE circuitonto the pin 2. The detectors (diode-blocks) control the operation of theMUTE circuit, preventing the LF (AF) signal to reach the output pin (2) untilthe tuning on the station that creates the signal in the antenna that is strongenough for quality reception is obtained.
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FM AntennasThis article relies heavily on the four part article:
“What Kind of FM Antenna is Best for You?”, by Michael J. Salvatti,appearing in Audio Magazine January through April 1978
Although that article series is excellent, and contains a lot of verydetailed information, it is now becoming somewhat dated, with manymanufacturers mentioned going out of business, and others changing theirproduct lines extensively and discontinuing specific models mentioned.Those who are curious can find the original article in libraries.
This article is meant for FM listeners who are dissatisfied with theperformance of the folded dipole antenna that came packaged with theirreceiver. Almost without exception, you will need to install an outdoorantenna. This article describes your options.
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patterns. Neither type has gain (over a standard dipole), in fact, both typeshave a slight loss. This can be an advantage in areas where a lot of strongstations are available. If the antenna had too much gain, the received signalsmight overload your receiver, especially if it is older. The effect of placingthe antenna higher than you could place a folded dipole will give you aneffective gain, and is the main benefit from this type of antenna.
“S” Curve (folded dipole) Antenna and its Polar Pattern
Turnstile Antenna and its Polar Pattern
High Gain Directional AntennasA high gain directional antenna is needed for weak distant stations.
Not only does it add gain, but its beamwidth can serve to reject other stations
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Simple FM Loop AntennaIntroduction
Not everybody can afford elaborate aerials. Nor does everyone hasthe space for large aerial arrays. So how about an aerial which is small,inexpensive and, more importantly, actually performs well?For years I havebeen singing the praises of a simple aerial called an “FM Loop”. I oftenrecommend this little antenna to newcomers to the hobby since they arevery simple to construct, cost next to nothing and, more importantly, performvery well considering their simplicity. How well? A single 33 inch square(84cm) turn of coax typically has around 5.5 to 6dB gain on its own, whichwill compare very favourably to many 5 element yagis! 33 inches (84cm) isa quarter wave for the FM broadcast band but you could easily adapt thesizes to suit other bands. The loop is wideband and therefore suitable forthe whole of the FM broadcast band and you can use it horizontally (coaxfeed point at the bottom) or vertically (coax feed point at the side).That’sright - it would often produce PI codes and PS names on my receiver’sdisplay, but the loop was just fixed to the wall! So why aren’t more of ususing these aerials? I don’t know! But I decided to put one to the test whileout hilltopping one night. The resulting log was impressive to say conditionswere as good as “flat” and the loop itself was only mounted around 8 feetabove the ground, resting on a tree branch!The reason this article has beenpublished is because the aforementioned log attracted a lot of interest andmembers wanted to know how to construct the FM loop to try out forthemselves.The history bitThe FM loop is simply a single element cubicalquad antenna. I have seen it described in other articles as “an excellentantenna”. Perhaps it would be simpler to compare its properties with thoseof the medium wave loop. It is of a slightly smaller size at band 2 frequenciesbut has the same figure-of-eight polar response and so receives both “frontand back” (180 degrees apart) with side nulls 90 degrees in between. Theside nulls are actually very deep. You can make this loop more directionalby adding appropriately sized and positioned “reflector” and “director” loopsas with a yagi though am only covering details of a single element loop forthis article. As with all aerials, the best results will be achieved if it ismounted clear of objects, though this little gem actually still performs prettywell in confined spaces, indoors, and even leaning against a wall or stood
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on the same or adjacent frequencies - coming from directions outside thebeamwidth. It can also reject sources of noise the same way. Noise caninclude reflections from nearby buildings or mountains, automobile ignition,large electrical installations or motors, or harmonics of CB and other typesof communications.
Directional antennas come in two basic types - Yagi and LogPeriodic, and hybrids are possible. Yagi’s are recognized by elements thatextend the entire width of the antenna, while log periodics are recognizedby elements that alternate between sides of the antenna. Yagi’s tend tohave higher gain and narrower beamwidths, while Log Periodics tend tohave more uniform gain over the FM band and wider beamwidths. Ageneralization that applies to both types of antennas is that the larger theyare (and the more elements they), the more gain and narrower beamwidththey will have. The reference above tends to favor log periodics, but I havefound that large Yagi’s are an absolute necessity for really weak or distantstations (300 miles is possible but rare).
Polar Pattern for Yagi and Log Periodic AntennasUsing TV Antennas
Extreme caution is advised here, as FM reception from TV antennasis unpredictable at best. It requires the antenna manufacturer to extend thegain of the low VHF band (channels 2-6) from 88 to 108 MHz, which almostdoubles the range. This is no small feat, and definitely involves compromisingthe performance for the low VHF TV channels - something that the antennamanufacturer may be unwilling to do. The majority of TV antennas simplyroll off in gain through the FM band. Some have traps to eliminate FMreception, because FM can interfere with TV channel 6. These antennasmay even have “break-off” elements to enable FM reception, so the usercan make a choice.
MANDATORY SAFETY RULES!1. Mount it so there is no possibility it could fall on power lines, or
power lines on it.
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2. Always use lightning arrestors. Even if you only get 2 inches ofrainfall a year, it only takes one strike to destroy your equipmentand/or kill you. Lightning arrestors will actually help you by bleedingoff static electricity charges.
3. Strength and stability - mount it no higher than you can mount itsecurely! If not, the first high winds it encounters will turn it or blowit down.
If you have carefully observed those safety rules - the rule forperformance is: “The higher the better, within your budget and zoning limits.”In practice, though, a ten foot mast on top of your house will give satisfactoryresults. FM is line of sight, but there is usually enough reflection in theatmosphere to help you. Mid-afternoon is usually the worst time for distantFM, and that is the time where raw height will help the most. Every mileadded to the line of sight comes at the expense of several feet of height,however. It may not be necessary to have line of sight, just line of sight to aregion where the signal is more receivable.
In cases where you are trying to receive a very weak station in ametropolitan environment, you may be able to see the tower. Although it isusually best to aim straight at the tower, there may be cases where it isnecessary to aim the antenna to reject interfering signals. both Yagis andLog Periodics are least sensitive to signals broadside to them. This isintuitive, because the receiving elements present the smallest surface areaon the sides of the antenna. It may be necessary to broadside your antennato an interfering station, even if you are aiming way off of the desired signal.In rare cases, it is better to aim the antenna at a building or mountain topick up the reflection of a station instead of the station itself. This happenswhen the building is relatively near and the station is several miles away. Ifyou aim at the station, the reflection from the building causes multipath. Ifyou aim at the building, you get the reflection, and the station - miles away- is rejected, eliminating the multipath.
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up on the ground. Because of it’s characteristics it is not easily detunedby being close to nearby objects.The construction bitThis aerial usesBodgitt & Scarper technology. It is so simple even I knocked one up in amatter of minutes. You don’t need to rely on my design, however, you maywish to make the construction a lot more sturdy, but the purpose of thisarticle is to show how you can achieve good results with the simplest ofconstructional effort. If you are going to use the loop externally for anextended length of time you would need to give it more strength. I constructedthe loop quickly to use in mobile situations where I just throw the loop upinto a tree or hang it on a branch. I will get round to constructing somethingmore solid one day - perhaps! This is what I used ...* Square woodendowelling around 2cm thick (around half an inch). Enough for four x 84cmlengths = 336cm total (or 4 x 33 inch lengths = 132 inches total). half aninch square).* At least 15 metres (50 feet) of good quality 75 ohm coaxcable* Screw terminal blocks* Sticky tape - duct / gaffer variety Alternatively,you could construct the loop out of plumbers copper pipe instead of coaxand some 90 degree corner joints. Make sure you insulate the copperthough with thick tape though if you intend to hang the loop on tree branches. Any physical contact *may* degrade performance.The receiving elementitself is a 33 inch 84cm square loop of the coax, so you will need to constructa suitably sized wooden frame, say 10mm (half an inch) less each side ofthe wooden dowelling around which you will wrap the coax - this is to makeallowances for the coax which will then be the correct size. The coax needsto have a feed point half way along the bottom of the frame so cut coax toa 336cm (11 feet) length and wrap this around the frame ensuring the innercore and outer (braid) are connected together, each end going into separateconnections on a small electrical screw terminal block. The remainder ofthe coax will be used for the downlead - you can vary the length accordingly. Connect the two ends of the loop to either side of the coax downlead via theterminal block, either way around, it doesn’t matter.The impedance of theFM Loop is 75 ohms. There has been much debate about this but this isstated in ARRL and RSGB information. Also, recent computer modellinghas given the impedance as 75 ohms at resonance too. The loop shouldbe positioned broadside to the transmitter for best pick-up, while the nullscan be found endways on. The loop also seems to have other quirkyattributes, exhibiting a slightly unidirectional pattern at times, but thesequirks can be of great use.So, in conclusion, this is aerial is very easy to
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COMMON FM RADIO
RECEPTION PROBLEMS
HissingIf your radio hisses it could be because it is receiving a weak signal.
This happens because radio receivers need reasonably strong
signals to decode the stereo component of an FM signal. A weak signal can
be caused if you are too far from a transmitter as well as large buildings or
hills blocking the signal path.
A good quality VHF Band 2 outdoor antenna correctly positioned to
pick up the best signal will usually always improve FM reception. If necessary,
a VHF Band 2 amplifier can be fitted to the antenna to boost a weak signal
as well.
If the radio is portable with no provision for plugging in an external
aerial, listeners should try adjusting the position of the radio’s own antenna
to improve the reception. Alternatively, moving the receiver to somewhere
else in the STAR 104.5FM: HOW TO FIX YOUR FM RADIO RECEPTION
DIFFICULTIES room may help particularly as FM reception can vary a great
deal over short distances. Radio reception is often better near windows or
upstairs rather than downstairs.
Distorted “S” Sounds on FM RadioThis phenomenon is known as “Multi-path Distortion.” Multi-path
distortion is characterised by sibilance which is the distortion of ’s’ and ‘z’
sounds used in speech to ‘shhhhh’ sounds. It is caused by the transmitted
54
construct. It is very efficient and seriously outperforms my FM whip withseveral extra dB of signal. As I have said, this loop has a big advantage inthat it works well indoors and doesn’t seem to mind too much where it islocated, making it an ideal aerial for beginners or those with no room oravailability for roof mounted antennas. It doesn’t look like much af a DXaerial but I have been very surprised by its performance and it has becomean essential part of my mobile DX setup. Used indoors at home I have beenable to eliminate Lincs FM on 102.2 and leave Galaxy from Birmingham atnoise-free listenable strength - something none of my other yagis or rooftopbeams have ever been able to achieve.
FM Dipole for 88-108 MHzA simple dipole antenna can be used for improved reception of FM broadcastsignals. A dipole is basically a length of conductor (wire) split into two portionsand signal is taken off at the split. It has a nominal 3 dB gain over anisotropic source and is directional, tending to favor signals coming broadsideto the wire. The dipole is customarily an electrical half wavelength of wire atthe frequency of interest, since the impedance under this condition is
55
theoretically 72 ohms resistive and is a good match to a 50-75 ohm sourceor load generally presented by interfacing equipment such as receivers andtransmitters designed to work into this range of impedances.
The length of a half wave dipole in feet is calculated as 468 divided by thefrequency in MHz or in inches as 5606/F mhz. This takes “end effect” intoconsideration, and also the fact that the dipole elements are of finitethickness, and works out as pretty close in practice. Therefore, a dipole for98 MHz which is band center of the FM broadcast band, works out to 4.78feet or 57.3 inches. The dipole would then consist of two lengths of wireeach 2.39 feet or 28.65 inches long, arranged as shown in the figure.
Coaxial cable can be used to connect to the antenna as shown,but for best results, a balun should be used to prevent feedline radiation orpickup, which tends to distort the pattern. For 88-108 MHz this can bemade by winding the coaxial feedline through a toroidal core or around aferrite rod. The idea is to insert a series impedance to shield currents onthe outside of the outer conductor, effectively decoupling it from the antenna.The current inside the line does not see this, as the inner and outerconductors are carrying equal and opposite currents and produce no externalmagnetic field, so no loss is experienced. The ferrite can be almost anythingthat yields a high impedance at the operating frequency. For 88 MHz to 108MHz, this can be a small toroid or rod with 3 to 4 turns of the cable. SeeFigure. We used a ferroxcube 768T188-4C4 material specified for 1 to 20MHz, wound with 3 turns of RG 174/U miniature coax. The measured losswas 0.3 dB including two connectors in the test setup, and the impedanceacross the toroid effectively in series with the outer surface of the shieldwas 1100 ohms shunted by -1.2 pf as read on a Boonton RX meter. This isover 10 times the feedline impedance and should be adequate.
The antenna should be mounted high and in the clear for very bestresults (30 feet away from anything else) and oriented facing favored directionof reception.
57
signal traveling to the listener’s radio receiver by more than one path. This
is usually caused by the signal being reflected off hills or tall buildings. The
reflected signal arrives at the receiving antenna a moment later than the
direct signal because it has traveled further. The reflected and direct signals
then interfere with each other causing the distortion.
The best way to minimise multi-path distortion is to use a directional
rooftop FM antenna which will only pick up signals coming directly from the
transmitter and reject signals that arrive at the back or side of the antenna.
It is also sometimes possible to mount the antenna so that a building screens
it from the reflections but not from the wanted signal. If multi-path distortion
is affecting a portable FM radio, try moving it to a different position in the
room.
Adjacent FM ChannelsAdjacent channel interference is caused by an FM station which is
close in frequency to the station being listened to. It can sound like a
twittering noise in the background. This problem is usually only apparent
on FM stereo but if the interfering station is very close in frequency, ie. only
50 or 100 kHz away, the effect may also be heard in mono.
GETTING THE BEST FM RADIO RECEPTION
AT HOME• Make sure the antenna is suitable for receiving FM radio and is pointing
in the direction of the radio transmitter at Somersby in Gosford.
• Check that the antenna cable and connections are in good condition.
60
InterferenceCar radios should be relatively immune to ignition and other electrical
interference from the vehicle, but failure of the vehicle’s electronic suppression
equipment can cause crackles and interference or:
• Rhythmic ticking varying with engine speed
• Whining varying in pitch with engine speed
• Regular crackling associated with a car heater or the windscreen
wipers/washers
In most cases, a reputable auto electrician can fix this sort of
interference.
Car AntennasCar radio antennas are always located externally and are usually a
telescopic rod, although there are a number of cars fitted with heated rear
window antennas or stubby helical wound antennas. To get the best from a
car radio:
• The antennas should be as high as possible, preferably on the roof and
away from the engine
• Telescopic antennas should be fully extended
• The antenna should not be folded back onto the roof and kept well clear
of the bodywork
• Antennas should be of the correct length - around 80 cm is ideal.
Antennas much shorter or longer than this may provide inferior results.
58
• If possible swap another radio for the affected one. If the radio reception
improves, there is likely to be an equipment problem with the first
radio - check the antenna.
• Sometimes the TV antenna is used for both the TV and FM radio. If
this is the case, remove the TV connection leaving only the direct
cable between STAR 104.5FM:
HOW TO FIX YOUR FM RADIO RECEPTIONDIFFICULTIESthe antenna and radio.
Listeners should also note that FM radio signals travel in almost straight
lines and are unable to travel over or penetrate large obstructions. This
usually means that parts of a coverage area may have a weak signal
particularly in hilly terrain or highly built up urban areas.
FM Dipole AntennaThe FM dipole antenna is economical and relatively simple to install,
whilst offering a considerable increase in reception quality. An FM dipole
antenna is built from TV ribbon cable, which is often supplied with hi-fi tuners
or can be purchased from an electronics store.
The length of the dipole antenna should be approximately 1.5m long and is
constructed by connecting the ribbon cable to the radio receiver. The dipole
antenna can be erected by attaching the cable to a wall with the 1.5m
section of the cable positioned horizontally where the best signal is found.
This antenna can be rotated to find the best position to further optimise
reception.
59
External FM AntennaThe best quality FM radio receiver system consists of an FM
antenna, permanently erected externally. As FM radio signals occupy the
same frequency band as some VHF television signals an FM antenna is
very much like a VHF television antenna. A VHF television antenna designed
to receive Band 2 TV channels may be used to improve FM radio reception.
A professional antenna installer can split the cable from the TV
antenna and then run separate cables to the TV and FM receivers. If a
splitter device is used, the signal strength is reduced. In some cases,
particularly in low signal strength areas, an amplifier may also be needed.
An amplifier boosts the signal and ensures that adequate signal strengths
are supplied to both the radio and the television set.
GETTING THE BEST
FROM YOUR CAR RADIO
The metal bodywork of a vehicle prevents signals reaching the radio,
so a quality external antenna is needed for good reception.
FM radio reception can be difficult when traveling in built-up areas
or in undulating terrain. Multi-path distortion or a weak signals may be
experienced. STAR 104.5FM: HOW TO FIX YOUR FM RADIO RECEPTION
DIFFICULTIES
However, FM radio generally gives good results with quality sound
and the option for stereo reception.
61
FM provides high-fidelity sound over broadcast radio. FM broadcastband is from 87.5 to 108.0 MHz. VHF band extends from 30 MHz to 300MHz. Thus FM belongs to VHF. The property of the High frequency signalsis that they propagate only in line of sight i.e., upto 50 to 100 Km .And thesesignals never reflects or refracts. But in the ionosphere these signals re-flects back to earth.
Dxing = D(Distant)+ X(Unknown)
DX communication is communication over great distances usingthe ionosphere to refract the transmitted radio beam. The beam returns tothe Earth’s surface, and may then be reflected back into the ionosphere fora second bounce. Ionospheric refraction is generally only feasible forfrequencies below about 50 MHz, and is highly dependent upon atmosphericconditions, the time of day, and the eleven-year sunspot cycle. It is alsoaffected by solar storms and some other solar events, which can alter theEarth’s ionosphere by ejecting a shower of charged particles.The angle ofrefraction places a minimum on the distance at which the refracted beamwill first return to Earth. This distance increases with frequency.
According to Dxing theory, an FM/TV signal from 700 to 1500 milescan be received.
64
Frequency Transmitter State / Location Station(MHz) Power (kW)
90.4 0.05 Maharashtra Pune Radio FTII (Film & Television Instiute of India)90.4 0.05 Pondicherry Madagadipet NILA FM (Sri Manakula Vidyanagar
Engineering College)90.4 0.05 Punjab Ludhiana Guru Nanak Girls’ College FM Radio Station90.4 0.05 Rajasthan Banasthali Radio Banasthali (Banasthali Vidyapheet
University)90.4 0.05 Rajasthan Jaipur FM Radio 7 (India International Institute of
Management, IIIM)90.4 0.05 Tamil Nadu Chennai [Madras] Anna FM @ 90.4 (Anna University)90.4 0.05 Tamil Nadu Dindigul Pasumai FM90.4 0.05 Tamil Nadu Erode (Perundurai) Kongu Engineering College (Kongu FM)90.4 0.05 Tamil Nadu Erode (Thiruchengode) Mugil FM (Erode Sengunthar Engineering
College)90.4 0.05 Tamil Nadu Tiruchirapalli Holy Cross College90.4 0.2 Tamil Nadu Yercaud (Salem) All India Radio (AIR FM Rainbow /
Akashvani)90.4 0.05 Uttar Pradesh Lucknow City Montessori School (CMS)90.8 0.05 Maharashtra Pune Vidyavani (University of Pune)90.8 0.05 Tamil Nadu Chennai [Madras] Loyola FM (Loyola College, Chennai)91.1 Andhra Pradesh Hyderabad Radio City91.1 Andhra Pradesh Visakhapatnam Radio City91.1 Delhi Delhi Radio City91.1 Gujarat Ahmedabad Radio City91.1 Gujarat Surat Radio City91.1 Gujarat Vadodara Radio City91.1 Karnataka Benguluru
[Bangalore] Radio City91.1 Maharashtra Ahmednagar Radio City91.1 20 Maharashtra Mumbai
[Bombay] Radio City91.1 Maharashtra Nagpur Radio City91.1 Maharashtra Solapur Radio City91.1 Rajasthan Jaipur Radio City91.1 Tamil Nadu Chennai [Madras] Radio City91.1 Tamil Nadu Coimbatore Radio City91.1 Uttar Pradesh Lucknow Radio City91.9 Goa Panaji Radio Indigo91.9 Haryana Hissar Radio Mantra 91.9 FM91.9 Haryana Karnal Radio Mantra 91.9 FM
62
A good DXing Pre-amplifier can be used.
You can use any type of antenna like telescopic antenna, It is betterto use, dipole antenna or Yagi antenna. Length of the dipole depends onfrequency. I am an Electronics Eng student, The circuits for dxing, booster,signal amp., were assembled by myself. All are available in the market.
The antenna for reception is designed by myself.
for eg. in yagi antenna, the dimensios as as follows:
The first director is 120 / F if F = 88 MHZ then 120 / 88 = 1,36 Meters.1 director 1 120 / frequencyA interval betwen 1 et 2 60 / frequency2 director 2 125 / frequencyB interval betwen 2 et 3 45 / frequency3 director 3 130 / frequencyC interval betwen 3 et 4 30 / frequency4 director 4 138 / frequencyD interval betwen 4 et 5 30 / frequency5 Dipôle 143 / frequencyE interval betwen 5 et 6 48 / frequency6 reflector 150 / frequencySuryan FM - Chennai - 93.5 MHzSuryan FM - Coimbatore - 93.5 MHzSuryan FM - Tirunelveli - 93.5 MHzSuryan FM - Madurai - 93.5 MHzSuryan FM - Tuticorin - 93.5 MHzSuryan FM - Pondicherry - 93.5 MHzSuryan FM - Trichy - 93.5 MHzSFM - Vishakapatinam - 93.5 MHzSFM - Bangalore - 93.5 MHz
63SFM - Hyderabad - 93.5 MHzSFM - Jaipur - 93.5 MHzSFM - Bhubaneshwar - 93.5 MHzSFM - Tirupati - 93.5 MHzSFM - Lucknow - 93.5 MHzSFM - Bhopal - 93.5 MHzSFM - Kozhikode - 93.5 MHzSFM - Indore - 93.5 MHzSFM - Vijayawada - 93.5 MHzSFM - Varanasi - 93.5 MHzSFM - Rajahmundry - 93.5 MHzSFM - Trivandrum - 93.5 MHz
SFM - Kanpur - 93.5 MHz
FM Radio Stations in IndiaFrequency Transmitter State / Location Station(MHz) Power (kW)90.4 0.05 Tamil Nadu Erode Kongu Arts and Science College90.4 0.05 Delhi New Delhi DU 90.4 FM (Delhi University)90.4 0.05 Delhi New Delhi Radio Jamia (Jamia Millia Islamia Uiversity)90.4 0.02 Goa Mapusa Voice of Xavier’s (VOX, St Xavier’s Colege
of Arts, Science & Commerce)90.4 Gujarat Ahmedabad Micavaani (Mudra Institute of
Communications)90.4 0.05 Gujarat Vallabh
Vidyanagar Vallabh Vidyanagar Campus Radio (SardarPatel University)
90.4 0.05 Karnataka Dharwad FM90.4 (Samudaya Banuli Kendra,University of Agricultural Sciences)
90.4 0.05 Kerala Thiruvananthapuram[Trivandrum] DC FM (D.C. Kizhakkemuri Foundation /
DCSMAT Media School)90.4 0.05 Maharashtra Baramati, Pune Vasundhara Vahini (Vidya Pratishthan
Institute of Information Technology, VIIT)
65Frequency Transmitter State / Location Station(MHz) Power (kW)
91.9 Karnataka Benguluru[Bangalore] Radio Indigo
91.9 Kerala Kozhikode[Calicut] Radio Mango 91.9 FM (Malayala
Manorama)91.9 Punjab Jalandhar Radio Mantra 91.9 FM91.9 Tamil Nadu Chennai [Madras] Aahaa FM91.9 10 Tamil Nadu Coimbatore Gyan Vani91.9 Uttar Pradesh Agra Radio Mantra 91.9 FM91.9 Uttar Pradesh Bareilly Radio Mantra 91.9 FM91.9 Uttar Pradesh Gorakhpur Radio Mantra 91.9 FM91.9 Uttar Pradesh Varanasi [Benares] Radio Mantra 91.9 FM91.9 West Bengal Kolkata [Calcutta] ZFriends FM (Ananda Bazaar Patrika group)92.7 Andhra Pradesh Hyderabad Big 92.7 FM92.7 Andhra Pradesh Tirupati Big 92.7 FM92.7 Andhra Pradesh Vishakhapatnam Big 92.7 FM92.7 Andhra Pradesh Vishakhapatnam Big 92.7 FM92.7 Assam Guwahati [Gauhati] Big 92.7 FM92.7 Chandigarh Chandigarh Big 92.7 FM92.7 Delhi Delhi Big 92.7 FM92.7 Goa Panaji Big 92.7 FM92.7 Gujarat Rajkot Big 92.7 FM92.7 Gujarat Surat Big 92.7 FM92.7 Gujarat Vadodara [Baroda] Big 92.7 FM92.7 Haryana Hissar Big 92.7 FM92.7 Jammu & Kashmir Jammu Big 92.7 FM92.7 Jammu & Kashmir Srinagar Big 92.7 FM92.7 Jharkhand Jamshedpur Big 92.7 FM92.7 Jharkhand Ranchi Big 92.7 FM92.7 Karnataka Benguluru
[Bangalore] Big 92.7 FM92.7 Karnataka Mangalore Big 92.7 FM92.7 Karnataka Mysore Big 92.7 FM92.7 Kerala Thiruvananthapuram
[Trivandrum] Big 92.7 FM92.7 Madhya Pradesh Bhopal Big 92.7 FM92.7 Madhya Pradesh Gwalior Big 92.7 FM92.7 Madhya Pradesh Indore Big 92.7 FM92.7 Maharashtra Mumbai
[Bombay] Big 92.7 FM
68Frequency Transmitter State / Location Station(MHz) Power (kW)
95 Rajasthan Jaipur Radio Tadka 95 FM95 West Bengal Kolkata II [Calcutta] All India Radio (AIR / Akashvani)*95.8 10 Gujarat Rajkot All India Radio (AIR / Akashvani / Vividh
Bharati)96 Assam Guwahati [Gauhati], Kamrup District All India Radio
(AIR / Akashvani)96 Assam Guwahati [Gauhati], Kamrup District All India Radio
(AIR / Akashvani)96.7 10 Gujarat Ahmedabad All India Radio (AIR / Akashvani / Vividh
Bharati)96.9 0.05 Delhi New Delhi IIMC Radio (Indian Institute of Mass
Communication, IIMC)97 West Bengal Kolkata [Calcutta] All India Radio (AIR Kolkata B /Akashvani)98.3 Andhra Pradesh Hyderabad Radio Mirchi98.3 Andhra Pradesh Vijayawada Radio Mirchi98.3 Bihar Patna Radio Mirchi98.3 Chhattisgarh Raipur Radio Mirchi98.3 Delhi Delhi Radio Mirchi98.3 Goa Panaji Radio Mirchi98.3 Gujarat Ahmedabad Radio Mirchi98.3 Gujarat Rajkot Radio Mirchi98.3 Gujarat Surat Radio Mirchi98.3 Gujarat Vadodara [Baroda] Radio Mirchi98.3 Karnataka Benguluru
[Bangalore] Radio Mirchi98.3 Karnataka Mangalore Radio Mirchi98.3 Kerala Thiruvananthapuram
[Trivandrum] Radio Mirchi98.3 Madhya Pradesh Bhopal Radio Mirchi98.3 Madhya Pradesh Indore Radio Mirchi98.3 Madhya Pradesh Jabalpur Radio Mirchi98.3 Maharshtra Kolhapur Radio Mirchi98.3 Maharashtra Mumbai [Bombay] Radio Mirchi98.3 Maharashtra Nagpur Radio Mirchi98.3 Maharshtra Nasik Radio Mirchi98.3 Maharashtra Pune [Poona] Radio Mirchi98.3 Punjab Jalandhar Radio Mirchi98.3 Rajasthan Jaipur Radio Mirchi98.3 Rajasthan Rajkot Radio Mirchi98.3 Tamil Nadu Chennai [Madras] Radio Mirchi
66Frequency Transmitter State / Location Station(MHz) Power (kW)
92.7 Maharashtra Solapur [Sholapur] Big 92.7 FM92.7 Orissa Bhubaneswar Big 92.7 FM92.7 Orissa Rourkela Big 92.7 FM92.7 Pondicherry Pondicherry Big 92.7 FM92.7 Punjab Amritsar Big 92.7 FM92.7 Punjab Jalandhar Big 92.7 FM92.7 Punjab Patiala Big 92.7 FM92.7 Rajasthan Ajmer Big 92.7 FM92.7 Rajasthan Bikaner Big 92.7 FM92.7 Rajasthan Jodhpur Big 92.7 FM92.7 Rajasthan Udaipur Big 92.7 FM92.7 Tamil Nadu Chennai [Madras] Big 92.7 FM92.7 Uttar Pradesh Agra Big 92.7 FM92.7 Uttar Pradesh Aligarh Big 92.7 FM92.7 Uttar Pradesh Allahabad 92.7 Uttar Pradesh Bareilly Big 92.7 FM92.7 Uttar Pradesh Jhansi 92.7 Uttar Pradesh Kanpur Big 92.7 FM92.7 West Bengal Asansol Big 92.7 FM92.7 West Bengal Kolkata [Calcutta] Big 92.7 FM92.7 West Bengal Siliguri High 92.7 FM (Sun Infomedia Pvt. Ltd.)93.5 Andhra Pradesh Hyderabad South Asia FM (S FM)93.5 Andhra Pradesh Rajahmundry Sun Networks (S FM)93.5 Andhra Pradesh Tirupati Kal Radio Ltd. (S FM)93.5 Andhra Pradesh Vijayawada Kal Radio Ltd. (S FM)93.5 Andhra Pradesh Visakhapatnam South Asia FM (S FM)93.5 Delhi Delhi Red FM93.5 Karnataka Benguluru
[Bangalore] South Asia FM (S FM)93.5 Karnataka Mangalore Kal Radio Ltd. (S FM)93.5 Kerala Kozhikode [Calicut] South Asia FM (S FM)93.5 Kerala Thrissur Kal Radio Ltd. (S FM)93.5 Madhya Pradesh Bhopal South Asia FM (S FM)93.5 Madhya Pradesh Indore Sun TV Network (S FM)93.5 Maharashtra Mumbai [Bombay] Red FM93.5 Orissa Bhubaneshwar South Asia FM (S FM)93.5 Pondicherry Pondicherry South Asia FM (Kal FM / S FM)93.5 Rajasthan Jaipur South Asia FM (S FM)93.5 20 Tamil Nadu Chennai [Madras] Suryan FM93.5 10 Tamil Nadu Coimbatore Suryan FM
67Frequency Transmitter State / Location Station(MHz) Power (kW)
93.5 Tamil Nadu Madurai Suryan FM93.5 Tamil Nadu Tiruchirapalli Kal Radio Ltd (S FM)93.5 Tamil Nadu Tirunelveli Suryan FM93.5 Tamil Nadu Tuticorin
[Thoothukudi] Suryan FM93.5 Uttar Pradesh Kanpur South Asia FM (S FM)93.5 Uttar Pradesh Lucknow South Asia FM (S FM)93.5 Uttar Pradesh Varanasi [Benares] South Asia FM (S FM)93.5 West Bengal Kolkata [Calcutta] Red FM93.9 10 Gujarat Vadodara [Baroda] All India Radio (AIR / Akashvani /
Vividh Bharati)94.3 Chandigarh Chandigarh MY FM (Bhaskar Group)94.3 Chhattisgarh Bilaspur MY FM (Bhaskar Group)94.3 Chhattisgarh Raipur MY FM (Bhaskar Group)94.3 Delhi Delhi Radio One94.3 Gujurat Ahmedabad MY FM (Bhaskar Group)94.3 Gujurat Surat MY FM (Bhaskar Group)94.3 Karnataka Benguluru
[Bangalore] Radio One94.3 Kannur Thrissur Club FM 94.3 (Mathrubhumi)94.3 Kerala Thrissur Club FM 94.3 (Mathrubhumi)94.3 Madhya Pradesh Bhopal MY FM (Bhaskar Group)94.3 Madhya Pradesh Gwalior MY FM (Bhaskar Group)94.3 Madhya Pradesh Indore MY FM (Bhaskar Group)94.3 Madhya Pradesh Jabalpur MY FM (Bhaskar Group)94.3 Maharashtra Kolhapur Radio Tomato94.3 20 Maharashtra Mumbai [Bombay] Radio One (formerly Go 92.5)94.3 Maharashtra Nagpur MY FM (Bhaskar Group)94.3 Punjab Amritsar MY FM (Bhaskar Group)94.3 Punjab Jallandhar MY FM (Bhaskar Group)94.3 Rajasthan Ajmer MY FM (Bhaskar Group)94.3 Rajasthan Jaipur MY FM (Bhaskar Group)94.3 Rajasthan Jodhpur MY FM (Bhaskar Group)94.3 Rajasthan Kota MY FM (Bhaskar Group)94.3 Rajasthan Udaipur MY FM (Bhaskar Group)94.3 Tamil Nadu Chennai [Madras] Radio One94.3 West Bengal Siliguri Radio Misty FM (Sun Infomedia Pvt. Ltd.)*94.6 Maharashtra Mumbai [Bombay] Win 94.695 Delhi Delhi HIT 95 FM95 Kerala Thrissur Best 95 FM
69
Frequency Transmitter State / Location Station(MHz) Power (kW)
98.3 Tamil Nadu Madurai Radio Mirchi98.3 Uttar Pradesh Kanpur Radio Mirchi98.3 Uttar Pradesh Lucknow Radio Mirchi98.3 Uttar Pradesh Varanasi Radio Mirchi98.3 West Bengal Kolkata [Calcutta] Radio Mirchi100.1 6 Andhra Pradesh Kothagudem All India Radio (AIR / Akashvani)100.1 3 Karnataka Benguluru
[Bangalore] All India Radio (AIR ClassicalMusic Channel / Akashvani / AmruthaVarshini)
100.1 6 Maharashtra Ahmednagar All India Radio (AIR / Akashvani)100.1 1 Uttar Pradesh Gorakhpur All India Radio (AIR / Akashvani / Vividh
Bharati)100.2 6 Assam Haflong,North Cachar
Hills District All India Radio (AIR / Akashvani)100.2 10 Uttar Pradesh Lucknow All India Radio (AIR / Akashvani)100.2 6 Madhya Pradesh Shivpuri All India Radio (AIR / Akashvani)100.2 6 Punjab Patiala All India Radio (AIR / Akashvani)100.2 10-May West Bengal Kolkata II [Calcutta] All India Radio (AIR FM Gold / Akashvani)100.3 10 Karnataka Mangalore,Dakshina
Kannada District All India Radio (AIR / Akashvani)100.3 6 Puducherri
[Pondicherry] Karaikal All India Radio (AIR / Akashvani)100.3 6 Rajasthan Jaipur B All India Radio (AIR / Akashvani / Vividh
Bharati)100.3 10 Uttar Pradesh Allahabad All India Radio (AIR / Akashvani / Vividh
Bharati)100.3 6 West Bengal Asansol All India Radio (AIR / Akashvani)100.4 Karnataka Benguluru
[Bangalore] AIR Music Service100.4 Madhya Pradesh Mandla All India Radio (AIR / Akashvani)100.4 6 Uttar Pradesh Bareilly All India Radio (AIR / Akashvani)100.5 3 Jammu & Kashmir Jammu All India Radio (AIR / Akashvani)100.5 10 Karnataka Hospet All India Radio (AIR / Akashvani)100.5 6 Maharashtra Dhule All India Radio (AIR / Akashvani)100.5 10 Tamil Nadu Kodaikanal All India Radio (AIR FM Rainbow /
Akashvani)100.6 10 Karnataka Mysore All India Radio (AIR / Akashvani)100.6 6 Maharashtra Nagpur All India Radio (AIR / Akashvani / Vividh
Bharati)
72Frequency Transmitter State / Location Station(MHz) Power (kW)
101.9 10 Kerala Thiruvanathapuram[Trivandrum] All India Radio (AIR / Akashvani / VividhBharati)
101.9 6 Mizoram Lungleh All India Radio (AIR / Akashvani)101.9 3 Orissa Bolangir All India Radio (AIR / Akashvani)101.9 6 Uttar Pradesh Faizabad All India Radio (AIR / Akashvani)102 10 Andhra Pradesh Visakhapatnam All India Radio (AIR FM Rainbow Vizak /
Akashvani)102 6 Madhya Pradesh Shahdol All India Radio (AIR / Akashvani)102.1 3 Jharkhand Hazaribagh All India Radio (AIR / Akashvani)102.1 6 Karnataka Raichur All India Radio (AIR / Akashvani)102.1 6 Rajasthan Jodhpur All India Radio (AIR / Akashvani / Vividh
Bharati)102.1 10 Tamil Nadu Tiruchirapalli All India Radio (AIR FM Rainbow /
Akashvani)102.1 10 Uttaranachal Mussoorie
[Musoorie] All India Radio (AIR / Akashvani)102.2 1 Andhra Pradesh Vijayawada All India Radio (AIR / FM Rainbow
Krishnaveni)102.2 6 Chhattisgarh Chindwara All India Radio (AIR / Akashvani)102.2 6 Gujarat Godhra All India Radio (AIR / Akashvani)102.2 10 Jammu & Kashmir Kathua All India Radio (AIR / Akashvani)102.2 6 Karnataka Hassan All India Radio (AIR / Akashvani)102.2 6 West Bengal Murshidabad All India Radio (AIR / Akashvani)102.3 6 Bihar Purnea All India Radio (AIR / Akashvani)102.3 3 Daman & Diu Daman All India Radio (AIR / Akashvani)102.3 6 Haryana Hissar All India Radio (AIR / Akashvani)102.3 3 Karnataka Karwar,Uttara Kannada District All India Radio (AIR /
Akashvani)102.3 6 Kerala Kochi A [Cochin] All India Radio (AIR / Akashvani)102.3 6 Madhya Pradesh Guna All India Radio (AIR / Akashvani)102.3 10 Tamil Nadu Chennai II [Madras]All India Radio (AIR FM Gold / Akashvani)102.3 10 West Bengal Kurseong All India Radio (AIR FM Rainbow /
Akashvani)102.4 6 Andhra Pradesh Kurnool All India Radio (AIR / Akashvani)102.4 10 Gujarat Rajkot All India Radio (AIR / Akashvani / Vividh
Bharati)102.4 6 Maharashtra Akola All India Radio (AIR / Akashvani)102.4 West Bengal Kolkata [Calcutta] All India Radio (AIR Kolkata I / Akashvani)102.5 6 Bihar Patna All India Radio (AIR / Akashvani / Vividh
Bharati)
70Frequency Transmitter State / Location Station(MHz) Power (kW)
100.6 6 Orissa Berhampur All India Radio (AIR / Akashvani)100.6 6 Uttar Pradesh Varanasi [Benares] All India Radio (AIR / Akashvani / Vividh
Bharati)100.7 10 Uttar Pradesh Lucknow All India Radio (AIR FM Rainbow /
Akashvani)100.7 6 Chhatisgarh Raigarh All India Radio (AIR / Akashvani)100.7 6 Jammu & Kashmir Poonch All India Radio (AIR /
Akashvani)100.7 10 Maharashtra Mumbai II
[Bombay] All India Radio (AIR FM Gold / Akashvani)100.7 6 Mizoram Aizawl All India Radio (AIR / Akashvani)100.7 6 Rajasthan Churu All India Radio (AIR / Akashvani)100.8 10 Assam Guwahati [Gauhati],
Kamrup District All India Radio (AIR / Akashvani / VividhBharati)
100.8 6 Jharkhand Jamshedpur,East Singhbhum District All India Radio (AIR / Akashvani / Vividh
Bharati)100.9 6 Nagaland Mukokchung All India Radio (AIR / Akashvani)100.9 10 Andaman & Nicobar Islands Port Blair All India Radio (AIR /
Akashvani / Vividh Bharati)100.9 1 Himachal Pradesh Simla [Shimla] All India Radio (AIR / Akashvani / Vividh
Bharati)100.9 Tamil Nadu Yercaud (Salem) All India Radio (AIR / Akashvani)101 6 Jammu & Kashmir Bhaderwah All India Radio (AIR /
Akashvani)101 6 Maharashtra Pune [Poona] All India Radio (AIR / Akashvani / Vividh
Bharati)101 5 Orissa Deogarh All India Radio (AIR / Akashvani / Vividh
Bharati)101 10 Tamil Nadu Nagercoil,Kanniyakumari
District All India Radio (AIR / Akashvani)101 West Bengal Kolkata [Calcutta] All India Radio (AIR / Akashvani / Vividh
Bharati)101.1 6 Gujarat Surat All India Radio (AIR / Akashvani / Vividh
Bharati)101.1 6 Maharashtra Nanded All India Radio (AIR / Akashvani)101.1 6 Meghalaya Jowai All India Radio (AIR / Akashvani)101.1 6 Punjab Bathinda All India Radio (AIR / Akashvani)101.2 6 Madhya Pradesh Khandwa,East Nimar
District All India Radio (AIR / Akashvani)
71Frequency Transmitter State / Location Station(MHz) Power (kW)
101.3 10 Karnataka Benguluru [Bangalore] All India Radio (AIR FM Rainbow /
Akashvani)101.3 6 Madhya Pradesh Balaghat All India Radio (AIR / Akashvani)101.3 6 Maharashtra Osmanabad All India Radio (AIR / Akashvani)101.3 6 Orissa Cuttack All India Radio (AIR FM Rainbow /
Akashvani)101.3 10 Puducherri
[Pondicherry] Pondicherry All India Radio (AIR / Akashvani)101.3 6 Rajasthan Banswara All India Radio (AIR / Akashvani)101.3 6 Uttar Pradesh Aligarh All India Radio (AIR FM Rainbow /
Akashvani)101.4 6 Haryana Kurukshetra
[Kurushetra] All India Radio (AIR / Akashvani)101.4 6 Kerala Devikulam All India Radio (AIR / Akashvani)101.4 6 Maharashtra Nasik All India Radio (AIR / Akashvani)101.4 20 Tamil Nadu Chennai I [Madras] All India Radio (AIR FM Rainbow /
Akashvani)101.4 10-Mar West Bengal Siliguri All India Radio (AIR / Akashvani / Vividh
Bharati)101.5 6 Andhra Pradesh Markapur All India Radio (AIR / Akashvani)101.5 6 Kerala Kannur [Cannanore] All India Radio (AIR / Akashvani)101.5 6 Rajasthan Sawai Madhopur All India Radio (AIR / Akashvani)101.6 10 Chhatisgarh Raipur All India Radio (AIR / Akashvani)101.6 6 Madhya Pradesh Indore All India Radio (AIR / Akashvani / Vividh
Bharati)101.6 10 Tripura Agartala All India Radio (AIR / Akashvani / Vividh
Bharati)101.7 6 Andhra Pradesh Anantapur All India Radio (AIR / Akashvani)101.7 6 Jharkhand Chaibasa [Chaibassa],
West Singhbhum District All India Radio (AIR / Akashvani)101.7 1 Maharashtra Aurangabad All India Radio (AIR / Akashvani)101.7 1 Rajasthan Udaipur All India Radio (AIR / Akashvani / Vividh
Bharati)101.8 6 Himachal Pradesh Hamirpur All India Radio (AIR / Akashvani)101.8 6 Karnataka Bijapur All India Radio (AIR / Akashvani)101.8 10 Rajasthan Jaisalmer All India Radio (AIR / Akashvani)101.9 10 Andhra Pradesh Hyderabad All India Radio (AIR / Akashvani / Twin
Cities FM Rainbow)101.9 10 Jammu & Kashmir Rajouri All India Radio (AIR / Akashvani)
73Frequency Transmitter State / Location Station(MHz) Power (kW)
102.5 6 Himachal Pradesh Kullu All India Radio (AIR / Akashvani)102.5 10 Tamil Nadu Dharmapuri All India Radio (AIR / Akashvani)102.6 10 Delhi Delhi I All India Radio (AIR FM Rainbow /
Akashvani)102.6 10 Jammu & Kashmir Srinagar All India Radio (AIR / Akashvani / Vividh
Bharati)102.6 6 Karnataka Chitradurga All India Radio (AIR / Akashvani)102.6 5 Madhya Pradesh Sagar All India Radio (AIR / Akashvani)102.6 6 Orissa Rourkela All India Radio (AIR / Akashvani)102.7 6 Assam Nagaon All India Radio (AIR / Akashvani)102.7 10 Kerala Manjery All India Radio (AIR / Akashvani)102.7 6 Maharashtra Kolhapur All India Radio (AIR / Akashvani)102.7 6 Maharashtra Yeotmal [Yavatmal] All India Radio (AIR / Akashvani)102.7 10 Punjab Jalandhar All India Radio (AIR FM Rainbow /
Akashvani)102.7 6 Rajasthan Obra All India Radio (AIR / Akashvani)102.8 6 Andhra Pradesh Hyderabad All India Radio (AIR / Akashvani / Vividh
Bharati)102.8 Chhattisgarh Saraipalli All India Radio (AIR / Akashvani)102.9 10 Karnataka Bangalore II All India Radio (AIR / Akashvani / Vividh
Bharati)102.9 10 Madhya Pradesh Jabalpur All India Radio (AIR / Akashvani / Vividh
Bharati)102.9 6 Maharashtra Beed All India Radio (AIR / Akashvani)102.9 5 Orissa Baripada All India Radio (AIR / Akashvani)102.9 6 Rajasthan Chittorgarh All India Radio (AIR / Akashvani)103 6 Jharkhand Daltonganj,
Palamau District All India Radio (AIR / Akashvani)103 10 Karnataka Dharwad All India Radio (AIR / Akashvani)103 6 Maharashtra Chandrapur
[Chanderpur] All India Radio (AIR / Akashvani)103 10 Nagaland Kohima All India Radio (AIR / Akashvani)103 10 Tamil Nadu Coimbatore All India Radio (AIR FM Rainbow /
Akashvani)103 6 Uttar Pradesh Jhansi All India Radio (AIR / Akashvani)103 West Bengal Kolkata [Calcutta] All India Radio (AIR Kolkata A /
Akashvani)103.1 10 Arunachal Pradesh Itanagar All India Radio (AIR / Akashvani)103.1 6 Chandigarh Chandigarh All India Radio (AIR / Akashvani / Vividh
Bharati)
76
Frequency Transmitter State / Location Station(MHz) Power (kW)
106.4 Haryana Karnal Radio Dhamaal 24 (BAG Films & Media Ltd)106.4 Jharkhand Ranchi Radio Dhamaal 24 (BAG Films & Media Ltd)106.4 Madhya Pradesh Jabalpur Radio Dhamaal 24 (BAG Films
& Media Ltd)106.4 Maharashtra Dhule Radio Dhamaal 24 (BAG Films & Media Ltd)106.4 Pondicherry Pondicherry Hello FM (Malar Publications)106.4 Punjab Patiala Radio Dhamaal 24 (BAG Films & Media Ltd)106.4 Tamil Nadu Chennai Hello FM (Malar Publications)106.4 Tamil Nadu Coimbatore Hello FM (Malar Publications)106.4 Tamil Nadu Madurai Hello FM (Malar Publications)106.4 Tamil Nadu Tirunelveli Hello FM (Malar Publications)106.4 Tamil Nadu Tuticorin
[Thoothukudi] Hello FM (Malar Publications)106.6 10 Madhya Pradesh Indore Gyan Vani107 10 West Bengal Kolkata I [Calcutta] All India Radio (AIR FM Rainbow /
Akashvani)107.1 10 Maharashtra Mumbai I
[Bombay] All India Radio (AIR FM Rainbow /Akashvani)
107.2 10 Himachal Pradesh Kasauli All India Radio (AIR National Channel /Akashvani)
107.2 10 Karnataka Bengalaru[Bangalore] Gyan Vani
107.4 10 Uttar Pradesh Allahabad Gyan Vani107.5 10-Mar Andhra Pradesh Tirupati II All India Radio (AIR / Akashvani)107.5 10 Kerala Kochi B [Cochin] All India Radio (AIR / Akashvani / FM
Rainbow)107.8 10 Assam Guwahati [Gauhati] Gyan Vani107.8 10 Gujarat Rajkot Gyan Vani107.8 0.05 Karnataka Bengalaru
[Bangalore] Radio Active (RA, Jain Group ofInstitutions)
107.8 10 Maharashtra Nagpur Gyan Vani107.8 0.05 Tamil Nadu Chennai [Madras] MOP FM (MOP Vaishnav College)107.8 West Bengal Kolkata [Calcutta] Power 107.8 FM
74Frequency Transmitter State / Location Station(MHz) Power (kW)
103.1 6 Karnataka Madikeri,KodaguDistrict All India Radio (AIR / Akashvani)
103.1 6 Madhya Pradesh Betul All India Radio (AIR / Akashvani)103.1 6 Maharashtra Satara All India Radio (AIR / Akashvani)103.1 6 Rajasthan Alwar All India Radio (AIR / Akashvani)103.1 3 West Bengal Shanti Nikethan All India Radio (AIR / Akashvani)103.2 6 Andhra Pradesh Nizamabad All India Radio (AIR / Akashvani)103.2 10 Andhra Pradesh Tirupati I All India Radio (AIR / Akashvani)103.2 6 Chhattisgarh Bilaspur All India Radio (AIR / Akashvani)103.2 6 Rajastham Jhalawar All India Radio (AIR / Akashvani)103.2 6 Tripura Kailashahar All India Radio (AIR / Akashvani)103.3 6 Assam Dhubri All India Radio (AIR / Akashvani)103.3 6 Jharkhand Ranchi All India Radio (AIR / Akashvani / Vividh
Bharati)103.3 1 Tamil Nadu Madurai All India Radio (AIR / Akashvani)103.4 10 Assam Jorhat All India Radio (AIR / Akashvani)103.4 6 Bihar Sasaram All India Radio (AIR / Akashvani)103.4 10 Himachal Pradesh Dharamsala All India Radio (AIR / Akashvani)103.4 3 Orissa Puri All India Radio (AIR / Akashvani)103.5 10 Andhra Pradesh Warangal
[Waranagal] All India Radio (AIR / Akashvani)103.5 1 Haryana Rohtak All India Radio (AIR / Akashvani / Vividh
Bharati)103.5 6 Madhya Pradesh Bhopal All India Radio (AIR / Akashvani / Vividh
Bharati)103.5 6 Manipur Churachandpur All India Radio (AIR / Akashvani)103.5 10 Manipur Imphal All India Radio (AIR / Akashvani)103.5 6 Rajasthan Mount Abu All India Radio (AIR / Akashvani)103.6 10 Kerala Kozhikode [Calicut] All India Radio (AIR / Akashvani / Vividh
Bharati)103.6 10 Meghalaya Shillong All India Radio (AIR / FM Rainbow)103.7 1 Karnataka Gulbarga All India Radio (AIR / Akashvani / Vividh
Bharati)103.7 6 Rajasthan Nagaur All India Radio (AIR / Akashvani)103.7 6 Tripura Belonia All India Radio (AIR / Akashvani)104 Delhi Delhi Fever 104 FM (HT Media Ltd / Virgin)104 Haryana Hissar Radio Tarang104 Karnataka Benguluru
[Bangalore] Fever 104 FM (HT Media Ltd / Virgin)104 Maharashtra Mumbai [Bombay] Fever 104 FM (HT Media Ltd / Virgin)
75Frequency Transmitter State / Location Station(MHz) Power (kW)
104 Orissa Bhubaneswar Cokelate 104 FM104 Orissa Rourkela Cokelate 104 FM104 10 Uttar Pradesh Kanpur Gyan Vani104 West Bengal Kolkata Fever 104 FM (HT Media Ltd / Virgin)104 West Bengal Kolkata II [Calcutta] All India Radio (AIR / Akashvani)104.2 Madhya Pradesh Bhopal Gyan Vani104.2 10 Tamil Nadu Chennai [Madras] Gyan Vani104.5 10 Jammu & Kashmir Jammu B All India Radio (AIR / Akashvani / Vividh
Bharati)104.8 Delhi Delhi Radio Today (Radio Meow FM)104.8 10 Maharashtra Aurangabad Gyan Vani104.8 Maharashtra Mumbai Radio Today (Radio Meow FM)104.8 Tamil Nadu Chennai Muthoot Group104.8 West Bengal Kolkata [Calcutta] Radio Today (Radio Meow FM)105 Madhya Pradesh Bhopal Gyan Vani105.2 10 Karnataka Mysore Gyan Vani105.4 6 Goa Panaji All India Radio (AIR FM Rainbow /
Akashvani)105.4 10 Gujarat Ahmedabad Gyan Vani105.4 10 Meghalaya Shillong Gyan Vani105.4 10 West Bengal Kolkata [Calcutta] Gyan Vani105.6 10 Andhra Pradesh Hyderabad Gyan Vani105.6 10 Andhra Pradesh Visakhapatnam Visakha FM105.6 10 Bihar Patna Gyan Vani105.6 10 Chhattisgarh Raipur Gyan Vani105.6 10 Delhi Delhi Gyan Vani105.6 10 Goa Patna Gyan Vani105.6 10 Karnataka Benguluru
[Bangalore] Gyan Vani105.6 10 Madhya Pradesh Bhopal Gyan Vani105.6 10 Madhya Pradesh Jabalpur Gyan Vani105.6 10 Maharashtra Mumbai [Bombay] Gyan Vani105.6 10 Rajasthan Jaipur Gyan Vani105.6 10 Uttar Pradesh Lucknow Gyan Vani105.6 10 Uttar Pradesh Varanasi [Benares] Gyan Vani106.2 West Bengal Kolkata [Calcutta] Amar 106.2106.4 10 Andhra Pradesh Visakhapatnam Gyan Vani106.4 Bihar Muzaffarpur Rad io Dhamaa l 24 (BAG F i lms & Med ia l td )106.4 5 Delhi Delhi II All India Radio (AIR FM Gold / Akashvani)106.4 Haryana Hissar Radio Dhamaal 24 (BAG Films & Media Ltd)