The interest of the VHF reflector has been tweaked by the picture in the December QST of a dual rhomboid as winning the 1296 section of the CSVHF conference antenna measurements in 1996. It was reported to have a gain of 17.3 dbi. One recent ham reference was in 73 Magazine for August 1977, pp. 24-7. This article referred to the original article by E. A. Laport and A. C. Veldhuis, "Improved Antennas of the Rhombic Class," RCA Review, March 1960, pp. 117 - 123. The 73 magazine article claims the antenna is suitable for 420 through 890 MHz with 26 dbd gain. I've made the statement on prior occasions that I've not found any arrangement of wire cats cradle that approaches the performance of the long yagi, and I stick by it with ideas of proving it wrong in the future. Laport's article shows an antenna over real earth designed for 8.5 MHz, but shows patterns and data over the range of 5 to 12.5 MHz. His performance data indicates greater signal strength and longer time periods of useful signal than a reference simple rhombic. The reference rhombic was .68 wavelength high with side lengths of 2.94 wavelengths oriented for the same distant station as the dual rhomboid. With a vertical beamwidth of 6 degrees (centered at 9 degrees) and a horizontal beamwidth of 11 degrees at 8.5 MHz, Laport claims a gain of 27 dbd. His azimuth plots are linear in voltage which effectively hides many sidelobes. Here's what I found with the antenna in free space using EZNEC: Frequency - MHz 210 254 305 432 610 740 890 Gain - dBi 9.86 12.11 14.38 17.31 17.18 14.03 16.13 Strong side lobe - dB -7.2 -7 -8.5 -10.2 -6.4 +1 +14 db @ - degrees 59 52 45 45 11 8 6 F/B 15 18 27 21 17 15 12 Number of lobes 14 22 22 35 45 62 70 lobes > -20 db 12 14 10 15 20 42 38 lobes > -10 db 3 3 3 1 4 14 14 Magnitude Z - ohms 231 316 335 303 300 334 355 Angle Z - degrees -1 -16 -7 10 13 7 13 Power to loads - % 56.9 44.2 37.3 33.2 30.7 28 17.1 (Continued Page 6)

We’re back on track here at Rocky Mountain VHF+ and we need to know your June contest plans for the May issue. It’ll be out on time, prior to the June VHF contest, and if the participation for the 2 meter Sprint was any indication it looks like we may have a really good turn out for this June. If you have e-mail, e-mail us direct. Snail mail will make it to the P.O. Box in plenty of time for our May issue. If we haven’t heard from you yet, now is the time to drop us a line and let us know what your contest plans are… 73 N0POH y KB0YRX

Report of Analysis of Laport Dual

Rhomboid Antenna for VHF use

Get youR june plans

to us NOW!

PAGE 2

ROCKY MOUNTAIN VHF+ AWARDS

To celebrate our ARRL club affiliation, Rocky Mountain VHF+ is offering the following free awards to all Amateur Operators. Each award is a Certificate suitable for framing. All contacts must be made in 1997 from one location except for the Rover Award.

WORKED COLORADO 50 MHz AWARD

WORKED COLORADO 144 MHz AWARD

Complete contacts with a minimum of 20 Colorado Stations in a minimum of 6 Colorado grid squares.

WORKED ALL COLORADO 50 MHz AWARD

WORKED ALL COLORADO 144 MHz AWARD

Complete contacts with at least 40 Colorado Stations with at least one in each of the 16 grid squares in Colorado.

Rover Awards You must work one station from each of 6 Colorado grids for the

VHF+ APRIL 1997

Editor Wayne N0POH

Publisher Joan KB0YRX

Heinen

All articles, comments and

other contributions may

be sent to:

Rocky Mountain VHF+

PO Box 473411 Aurora, CO 80047-3411

Email: Wayne.heinen@filebank.com

or nrclog@filebank.com

Packet N0POH@KTOH.#NECO.CO.USA

(303) 699-6335 before 8PM MST

SUBCRIPTIONS RATES BY FIRST CLASS MAIL

UNITED STATES $16.00 PER

YEAR CANADA $18.00 PER YEAR

Worked Colorado Award or one station from all 16 Colorado grids for the Worked All Colorado Award. You also need make the required number of total contacts.

All awards are based on your personal integrity and your log submission. No

QSL cards are required.

The following Amateurs qualified for the 1996 Worked Colorado Award. W2CRS, W6OAL, KD0DW, N0UOC, WG6K and N0POH. This award was designed by KB0YRX and is printed on light blue paper in FULL COLOR. (I knew we’d find a way to use Joan’s Christmas present!) . A Black and White is shown below. This Certificate is definitely Suitable for framing , as mine is already framed.

VHF+ APRIL 1997 PAGE 3

for go it this week in lieu of the 'sprint'. Hope the other 'sprints' are as much fun as this one. CU all 73, Dave... (Dave had this on the reflector, in RMVHF+ he’s preaching to the Choir! - POH)

Jay K0GU DN70 Jayk@bits.fc.hp.com

Caught my first AU opening last night. Didn't sound quite like I expected. It basically sounded like loud white noise. Guess I was expecting a buzz or something. Below is what I worked from CO. Forgot to write down a couple of the RST reports. RCVD SENT GRID 0205 WA2HFI/0 53A 53A EN34 0212 WB0SOK 55A 53A EN34 0214 WY0V 55A 54A EN12 0215 WB9SNR 55A 53A EN62 0218 N0LL 54A 52A EM09 0219 K0KD 56A 5?A EN31 0233 KB0PYO 59A 56A EN24 0235 KA0RYT 52A 53A EN34 0237 K8SD 55A 53A EN12 0241 WB9HLM 52A 53A EN52 0246 WA9KRT 52A 53A EN61 0251 K0MQS 55A 56A EN31 0258 KA0ZYD 53A EN34 0303 W0LER 55A 53A EN35 Heard W7HAH, big signals KB0PYO and K0MQS. Don't know how much I missed as the band was open when I got on at 02z. Heard nothing after ~0315 but I kept CQing till after 04z. Spent a fair amount of time CQing toward the northwest with no results. Great fun, lets do it again tonight :-). FT-1000D DEM 144-28 Swan VHF-150 8877 4x17B2 SSB preamp mast mounted

Ken W0ETT DM79 When operating 2 meter SSB mobile near Corpus Christi, TX on 3/21, I heard several South Texas stations, including KB5IUA near Houston, working into FL on 144.200. John later told me that it was the second night that they had tropo conditions into FL. He mentioned that it happens occasionally when humidity and

COLORADO

Dave W6OAL DM79 W6oal@aol.com

Hi, Don't know if it was from the 'flare' or just a good night on 432.1 MHz Wed. evening April 9, 1997. But, signals were very good from all over the Front Range. We had quite a round table going from Cheyenne to Colorado Springs. Direct paths were almost as strong as using Longs Peak for a common reflector as we sometimes have to do. WA7KYM in Cheyenne, WY had his antennas tied down to the East and was still Q5 in Littleton, CO. W0KJY - Jim in Ft. Collins was S9 all evening and he kept asking if the rest of us were hearing the spurts of CW in the background. I was hearing what I thought was syllables here and there as a cacophony but nothing intelligible. Just a passing note that people might be interested in, will monitor 144.2 as well as 50.125 today in anticipation of something happening. Would like to see more participation on 432.1 MHz Wed evenings starting at 8 PM local. There's usually about six of us on every week. Not a bragging list about the 2M sprint, just a fun time. I thought the turn out was good here in DM79 (Denver Area). I only operated about 3 of the 4 hours and made 31 QSOs in 11 grids in 4 states. Remember here in the West we don't have the population to 'cherry pick' from a hill above a large metropolis on 52 FM. All our VHF/UHF DX contacts are fairly hard fought for. All in all I think it was a good get-to-gather, blow the dust out of our rigs and just have a good time. The net, Friends on 2M SSB Net, will resume again next week on 144.220 MHz, 7:30 PM MDT. We thought it judicious to

temperatures get high. I didn't work any DX with my 25 W. After I told John of our slim DX pickings in CO, KB5IUA went to say that he has regularly worked 150 -180 grids per year on 2 mtrs. He has been able to work the FL path on UHF frequencies as high as 1296.

N0SWV Jesse J. Alcorta Alcortje.Asa@asa.org

Interesting 2M Sprint on 4/14/97. I only had 33 contacts but did manage 12 grids, three of them new for me working from DM79. Worked into WY, KS, OK, NM as well as CO. Where were the NE and TX stations? Too bad there weren't more local participants from the Front Range area since many of the KS/OK/NM stations were booming in. I almost made the Worked Colorado Award to boot but couldn't get the one extra grid needed. Grids worked included: DM65, DM76, DM78,DM79, DM89, DM98, DN70, DN71, DN80, EM06, EM08 and EM09. Thanks to N0IVN for the rover effort which gave me one needed grid. If this is any indication of what the summer holds for us we should have a great tropo season. Missed the spectacular aurora last week. I tried to work some of it but failed since I haven't changed the antenna on the roof to the large unit yet. The extra dbd are almost essential from the home QTH as opposed to Daniel's Park. How many people are planning on working the June contest? Sounds early but I think that we should start considering how much noise we need to make if we don't want to be considered "the DX station". Right now I don't have any radios to lend but I might be able to loan at least one 14 dbd 2M beam if someone wanted to go portable somewhere "special".....

VHF+ APRIL 1997 PAGE 4

the duration of the radio aurora. All contacts were on 2M, as 222 yielded no results. K8SD 54A EM12 IA W0OHU 53A EN34 MN K0MQS 56A EN31 IA N0GXA 58A EN13 SD WY0V 57A EN12 IA WA2HFI 56A EN34 MN K0GU 54A DN70 CO KA0ZYD 52A EN34 MN N0CIQ 42A EN44 WI K8BHZ 57A EN75 MI WB0SOK 54A EN34 MN These and other stations would be heard calling CQ, I would answer but they would answer an 8 or 9 or someone I was not hearing. The curtains a few degrees farther South would of helped. Oh well the Aurora wasn't great but at least it was something.

NEBRASKA

Jim WD0BQM DN81cw jweber@hannibal.wncc.cc.ne.us

I'm going to be TDY at Gowen Field in Boise, ID from 26 April to 10 May...wonder how much vhf/uhf activity there is. I might be able to take an IC-260 and horizontal loop with me.

Wayne N0POH DM79op

nrclog@filebank.com

Missed the AU on 4/11 but did work the 2m sprint 27 Q's in 8 grids with my trusty 4el and 25w. Thanks to N0KQY DM98 for grid #19 on 2m for the QRP setup. Enjoyed moving well away from the calling frequency and rag chewing with a number of folks. We were hoping for some upgrades but we'll have to see how the money tree holds out this spring and summer.

Phil N0KE DM69 (Our apologies to Phil for misplacing this report it should have ran in March’s issue -W&J) When the FCC vanity flood gates reopened on February 12, 1997 I ended up with my 2nd choice of N0KE. At least there is some resemblance of the old call preserved which should cut sown on some confusion. After seeing the number of people who changed, I figured that I might as well have people learn a new one for me as well, and since I like to contest it would shorten it. Testing it in the ARRL SSB DX contest under poor conditions, it seemed nicer to have one less letter to get through. If the snow ever melts in time in June we hope to give it a good work out from our favorite spot in DM69. On Feb 1 I met AC6IO at the Grand Mesa contesters meeting in Grand Junction and later went by his station. (His Dad is K5RHR) During the January VHF he had about 15 QSOs with New Mexico. He is active on 6, 222, and 432 and has ambitious plans for his station. After moving from California he is quite surprised at the lack of activity in these parts.

KANSAS

Larry N0LL EM09 N0ll@ruraltel.net

The media convinced many VHFers an aurora would show up Wednesday night local. It has been my experience those charged particles take 24 or so hours to develop into an aurora if they get stuck in the earth’s geomagnetic field, so I was on the watch. 11 QSO were made between 0127Z and 0310Z April 11th which was

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VHF+ APRIL 1997 PAGE 5

Subj: AU FIZZES OUT ABOUT 10:10PM THE AU STAYED HERE IN EN92 TIL ABOUT 10:10 PM AND I CALLED IT QUITS. MAYBE IT CAME BACK BUT I GAVE UP AND WENT TO BED. MADE SEVERAL GOOD CONTACTS TO BOTH THE EAST, NORTH AND WEST. WITH THE AU COMING IN AND OUT AND CHANGING DIRECTIONS ON ME, FOUND THAT IF I DIDN'T MOVE ANTENNA ON BOTH SIDES OF NORTH I WAS MISSING STATIONS. ALSO WORKED VE2JWH FN35, K0MQS FN31, WA1JOF FN44, VE3FOD EN76 TO NAME A FEW. CONDITIONS GOT BETTER AS NITE PROGRESSED. 73'S TERRY WA3LTB EN92 144 MHZ AU INTO EN34 4/11 0200Z LOUD aurora into EN34 on 2M as we speak. Stations in EN34 working AU on 50, 144 & 222 MHz and looking for it on 432. 73 Rich N0HJZ (EN34fv) Au in progress since 0300 utc. Hearing Washington, Idaho, Oregon, British Columbia from DN17, Eastern WA Mike Pinault N3CEV/7 Anything Under 50Mhz Must Be DC! Near Spokane Washington DN17el I made my first aurora contacts on 2 meters tonight. I worked Michigan and Illinois, but heard New York, Minnesota, and SOuth Dakota. Didn't catch the grids on most of these. Signals were generally weak, but copyiable. I guess I need more power and better antennas for this sort of thing. I called quite a few stations, but was not heard by most. This was the first aurora I have worked since I worked Minneapolis on 6 meters in the mid 1960's. I was working on my homework in the computer lab tonight, and decided to check the e-mail. I saw the postings about the opening, finished the assignment in record time, and bolted for home. I managed to catch the last half hour or so of the opening. 73, Steve WA9JML FYI - without much time or effort worked following on AU on 4/11 between 0130-0535z FREQ 144.2 +/- from EN34oa to EM19, FN13, EN74, EN81, EN82 Lots of loud signals (and QRM) Only heard locals on 432.1 (no distance AU signals) FOR John, W0LER reference his note: SURE LIKE TO KNOW WHO you worked in DM70!! on AU

from MN (EN35)....WOW!! 73, Ed, w0ohu EN34oa (144 & 432) As can be expected, the good AU condx brought on some auroral-E. Heared a number of stations out east. Couldn't catch anyone's attention until W2DRZ (FN02) heard me. Also worked KB8MBC (EN73). Right after that, KL7FZ and KL7Y (both in BP51) called me off the back of my beam. Worked a few other KL7's also. Also worked a few VE7s and W7s. All this happened between 0516Z and 0600Z (April 11) on 50.125. Barry Bergstrom VE6MK (ex-VE6BMR) DO33im PAGE FM MY LOGBOOK Here is a page from my logbook referencing my aurora activity for Apr 10, 1997 4/10/97 2244Z 144.2 KA0RYT EN34 2331 144.2 N4PZ EN52 2349 432.1 WD8KUF EN73 (Not AU, just friend making QSO, darn!) 4/11/97 0052 144.2 K9MRI EN70 0110 144.2 AC8W EN82 0120 50.1 N0USG EN34 0130 50.1 N8ZJN EM79 0133 50.1 KA8JOM EN66 0134 50.1 KB8MBC EN73 (Not AU, friend asking whats going on) 0200 144.2 KA0RYT EN34 (We try 432.1 unsuccessfully, darn!) 0235 144.2 VE3EGC EN76 (Not AU, he's QRP 10w.) 0258 144.2 W1REZ FN55 0305 50.1 VE3SXE FN25 0308 50.1 VE3FIT FN03 0312 50.1 VE2VAT FN45 0313 50.1 AA2QM FN34 I went to bed at 0400, there was still AU going on and plenty of stations to work. I could easily have made a (Continued Page 7) (Aurora Continued) hundred contacts on 2 meters, but I was concentrating my efforts to make my first 432 AU contact. Didn't happen this time though. Aurora died out several times during this period, but kept coming back after 10 or 15 minutes. 73 de Ken N8CGY

The 4/10-11 Aurora from the Reflector

(These are Unedited! - W&J) Nil hr in KS so far - copied a 9 calling CQ AU on 6 but no AU distortion on his signal. CBS featured the solar flare on the evening news with a prediction of this aurora being "bigger than 1989." Hope it pans out. - Jon N0JK Same thing for me here in EN54. I sat from approximately 6pm (CST) until around 2am calling CQ every couple of minutes. Never heard anything. Oh well. The hype was great, and as you mentioned it motivated me to sit down and "play" with this little rig! I am still looking forward to the bands opening up here in the summer. 73's, Austin Kyser KB9PCW Its now 0040 and Aurora still going strong...........on 2m only. I have heard a few bits of AU on 432 and 1 strong, short non-AU flutter signal on 432 also, but not enough to get a call and no answer came back after that. Still waiting for my first 70cm AU QSO...who's it gonna be? 73 de Ken N8CGY EN74oh K8SD, EN13 4/10 AU now 01:25 into MI, WI from SD SOME FAIRLY GOOD AU SIGNALS HERE IN EN92, WORKED COUPLE EN41 STATIONS FN55 EN52 FN23 , NOTHING SPECTACULAR BUT SOME ACTION ON 144 MHZ FOR A CHANGE..... GOOD DX, TERRY WA3LTB EN92 4/11 AU from CO (DN70) to IA and MN Ron Galbraith - N0EC DN70lf N0EC@qsl.net Got into the aurora late. Did manage to work W2AH DM78 & K0GU DM70. Lots of w8's and w9's. Was looking for new grids. Sure wish I could have been on earlier. Got on @ 0245 gmt. John W0LER

loads would get to the feed line. With so many strong side lobes, the noise of the terminations would be hidden by the earth noise picked up by the side lobes. Antennas such as K1FO or DL6WU yagis that have a good G/T rating have far cleaner patterns than this dual rhomboid. Since Laport claimed 27 dbd for the real earth situation and EZNEC shows 17.3 dbd, one might wonder about the reason for the difference. I believe its in the energy in the sidelobes in both planes. E.g. there is enough energy in 40 sidelobes each ten to 20 db down to account for 10 db less signal off the front. I've not investigated planes other than E or H. Likely there are lobes at odd angles not in either standard plane of measurement.Where'd he get his 27 dbd? Probably from a standard formula, gain = 10 log10 (35000/HV) dbd where H and V are horizontal and vertical pattern 3db points, but this formula presumes the side lobe energy is negligible and there are no losses in the antenna. Neither is true for this antenna. There are differing opinions on what the constant should be in this formula. Since it ignores sidelobes and efficiency it rarely produces a conservative gain figure. This antenna is 8.5 wavelengths long and 4.5 wavelengths wide. In G3SEK's "The VHF/UHF DX Book" the charts for DL6WU yagis show a gain of 16.6 dbd for an 8.8 wavelength boom. If a pair of these were stacked side by side, they would cover about the same real estate as the dual rhomboid and give 19.5 dbd (21.7 dBi) with low side lobes. Of course, it wouldn't do that over 20 MHz at 432... But this DL6WU array would have a super G/T that the dual rhomboids never will. On the other hand, the dual rhomboid does have a WIDE impedance bandwidth (with adequate pattern) from 254 through 610 MHz, so for wide band modes and proper scaling it might be a useful antenna. Gain certainly is higher than any VHF log periodic array I've ever

(LaPort Continued) I used the dimensions of the 73 article with frequencies of 254, 305, 432, and 610 MHz. The scaling appears to be such that the 432 range matches Laport's 8.5 MHz design frequency. I also used frequencies outside that range at 210, 740 and 890 MHz to check the effects of extreme frequency. Since running these, I have received a letter from Dayton Johnson with his dimensions. Which are essentially 1/3 the dimensions for 432 MHz. The numbers of lobes, lobes > -20 db and lobes > -10 db includes the front lobe when present in the azimuth plane. At 740 MHz the front lobe splits into three with the first side lobes 1 db stronger than the main front lobe. At 890 MHz the main lobe is down 14 db from the first side lobes, but still 12 db stronger than off the back. I might have missed counting a lobe or two when the resolution of my printer ran out on the fine lobes or lobes ran together. Over a real earth ground plane at 432 MHz, but at Laport's height in wavelengths (1.53), the patterns computed by EZNEC are very close to the patterns measured by Laport with an airplane. EZNEC reports a gain of 22.51 dBi, but you need to discount 3 db because it in halfspace, which leaves 19.5 dBi or 17.285 dbd. I've not tried applying two sources in place of the loads and a load in place of the common feed to see how much termination noise would reach the feed line, I expect it would be similar to the power transfer the other way, so that roughly 1/3 the noise power of the

seen, but the dual rhomboid can't be stretched to much more than this 2.4:1 frequency range without total destruction of the pattern. Based on the widely reproduced K2RIW 432 yagi, I'd expect construction tolerances for the DL6WU to be tight, probably 1/64" at 432, .005" at 1296. But tolerances for the dual rhomboid need to be tight also because its getting gain and reducing sidelobes by cancellation of sidelobes from various runs of wire while making the main wire lobes match. If those wires aren't positioned accurately (and Laport makes the point saying, "Due to the natural sharpness of secondary lobes in the patterns of long straight wires, the apex angles of the antenna must be exact for best sidelobe suppression." G3SEK tells me that DL6WU construction tolerances are not so tight. "I don't have personal experience of the FOs but the DL6WU/DJ9BV yagis degrade very gradually with element length errors. They are particularly tolerant of random errors." G3SEK continued, "DL6WU's measurements on a professional range showed that for his designs 'the length tolerance of an individual element is quite large as long as the mean value is maintained within about 0.5%.' That says that the mean error for half-wave elements at 432 MHz can be 1/16" (1.6mm), and errors in (Continued Page 8) (Laport Continued) individual elements can be greater if they are scattered evenly around the mean."

VHF+ APRIL 1997 PAGE 6

VHF+ APRIL 1997 PAGE 7

From Tad Cook, KT7H Seattle, WA April 18, 1997 To all radio amateurs SB PROP ARL ARLP016 ARLP016 Propagation de KT7H Average solar flux was down a little with sunspot numbers up a bit over the past week. The most significant event was the delayed reaction to the big solar mass ejection, which drove the Planetary A index to 38 and K index up to 7 on April 11. Over the next few days watch for a retreat in the solar flux from the high seventies down to the low seventies until the end of the first week in May, when it will start creeping up to the eighties again. Solar flux is expected to be above 80 by May 10. Look for geomagnetic disturbances to appear again around April 24 and 25. All of this forecast is based upon activity seen during the last solar rotation, and of course new activity could appear at any time. Sunspot Numbers for April 10 through 16 were 47, 31, 30, 34, 45, 39 and 33 with a mean of 37. 10.7 cm flux was 77.6, 77.1, 76.4, 78.8, 77.4, 78.7 and 75, with a mean of 77.3, and estimated planetary A indices were 10, 38, 9, 8, 4, 4, and 12, with a mean of 12.1. NNNN /EX Courtesy of the W1AW info server via Internet W&J

Houghton Lake, Mi EN74oh Wow had a great time. Best time was between 01:30 and 03:30 from here in SD, EN12 running only on 2 meters. 150 watts 12 el @ 35 ft. States worked, CO ND MN WI ILL MI IN MO KS Grids worked DN70 DN86 EN31 EN34 EN35 EN41 EN52 EN70 EN82 EM09 EM43 EM49 I heard VE3FOD. Hugh beacon stations were K0MQS EN31 and K0GU DN70 I heard all night until 05:00 or 06:00. Barry, K8SD If only I had more power! My 10 watts was obviously insufficient to make the ~700 (direct path) mile journey from MN to CO. That was the first time that I have heard CO up here on AU. Chris Cox, N0UK/G4JEC Didnt get down to the shack till after 01Z, found spots going back to at least 23Z on packet. Heard K1ZE/FN41/RI CQing (loud enough to override my noise blanker so the line noise would ride through), nothing else until suddenly there was K8BHZ, S9+, same frequency as ZE. BHZ must have had a real pileup as he sure took his time replying to anybody! Called a couple times but eventually moved on...then I heard WA2GSX/FN13, 55A. Worked him then realized I already had FN13 on 144...wasn't a loss, tho, since that was only my 2nd AU Q on 144 from this horrible QTH (the other was VE9AA a few months ago...TNX again, Mike!). To give you an idea of how bad this QTH seems to be, I never heard anything else that wasn't a W1! Lots of nice spots from KU8Y on packet, kept tuning to his frequencies (especially that VE3/EN76) but never heard anything. Didnt hear any other locals doing anything, either..they must have been pointed to the NW (I'm due north or NE of all those in CT so their beam pattern, when pointed NW, would make them pretty weak). Soon's I get a decent car again, I can try piling the radio and yagi in there and heading for nearby hills when an opening comes around. Until then, this QTH is like being at the bottom of a coffee cup or something... Oh, yes...I got called by a K9, I thought K9PU, who was real weak, right after I worked WA2GSX. At first, I dismissed him as the line noise sorta covered him and I figgered he was calling GSX; but after I tuned around the band for a few seconds and ran across PU still calling me, I finally got my rear in gear and called back. Of course, the

AU began to die for me at that point and I never really heard PU's grid. Did I get his call right? Sure didn't sound like K9CA, but MAYBE... WWV gave a couple of K7s this morning, and if I had a decent car that didnt smoke, I would have stayed home to try some more...but the way this thing smokes, I have to sneak the car to work before all the cops arrive at their road-work stations (yes, they use cops to "direct" traffic around roadwork sites here in Mass!!). Hereabouts, they dont even let you drive the car home if they stop you for any kind of safety inspection thing. Dumb, costly, and very profitable for tow truck operators...73, Steve Ko0U/1 FN42dg Had some decent AU last night from CN84JC, Eugene, OR. It began around 0330Z when I started to here K7NQ in CN87. First Q was VE7SKA/CN88 on 2 meters at 0352, then W7HAH/DN26 at 0355 (he was loud), K7JY/CN87, VE3GBA/7/CN88, W7OE/DN17, with time out to work WB7DHC on 6 meter SSB. It was only open for me until 0430 or so, and then when I came back later, near 0700, I heard VE7XF/CN89 on 6 quite loud for a few minutes. All in all an average opening this far south, nothing reall y wild, but hey, I'm not complaining! 73 Tom K7ZL Au usual the west coast faired poorly, at least in my opinion. Why don't they move the magnetic pole west? Worked W7YOZ (CN87) and (Continued Page 11) (Aurora Continued) heard W7OE, plus several others too weak to pull out. Opened late and closed early. Sigh. 73 K6ZX - CN82gm - Merlin, Oregon

While the 4/11 AU may not have "the mother of all Auroras" it was certainly impressive at this end. This is the first time that I've heard AU

VHF+ APRIL 1997 PAGE 8

Laport's article also shows a quad rhomboid that he claims has smaller sidelobes. Maybe some year when I've more time and less computer work for work and an EZNEC that will handle 1000 segments, I'll model it. Its too bad the QST editorial staff was wowed by the 17.3 dbi figure. That's not really great for a 1296 antenna. I checked in the results from the 1983 CSVHF conference and the 27 element Spectrum International loop yagi that I'm now using for 1296 did 17.8 dbi and its boom is only 6 feet long... As for "cats cradle," I have concocted some designs for 432 or 1296 that have gain equal to the Laport dual rhomboid, but with far fewer and far better suppressed side lobes, at least by EZNEC analysis. Computed gain bandwidths are about twice that of the DL6WU computation I'm using for reference. I've not built any of these and any performance claims need to be tested before I make them public. I made crude attempts at optimization which have made considerable improvements so they are surely not yet close to optimized. In February, I presented a program for the Story County (Iowa) ARC on the Laport dual rhomboid and my cats cradle ideas. I edited my slides down to about 70. I don't have a way to convert them to gif for showing here.

DUAL RHOMBIC REVISITED

Steve KO0U/1 Steveh@fons.com

I recall that some years back at a West Coast VHF Conference, somebody had a

terminated dual rhombic built for 432 that was tested on the antenna range Sunday morning. As I remember it, the antenna was apparently badly mistuned as it showed something less than 10 dB gain; the total length between apexes was 21 feet, I think. He used bamboo poles for the crossmembers similar to the spreaders used in the old cubical quads. The builder stated he'd built it based on the article in 73 magazine which had been recently published. Shortly afterward, I drove out to the high desert northeast of LA to buy a generator from a guy who had just gotten on 145 SSB/CW (that's how long ago all this was...145.2 was the calling frequency in SoCal until the early '80s). He had a nice, large plot of land in the desert, and was experimenting, along with a buddy of his in Las Vegas, with both rhombics and V-beams for 6 and 2 meters. He had a dual Vee beam for 2 meters that was essentially 1/2 of the dual rhombic lately publicized in QST for 432, something like around 120 feet leg length. His buddy in Las Vegas was using a single, relatively-small rhombic on his house roof. While I was there, the guy called his buddy in Vegas who came back, supposedly running just a barefoot TS-700S, well over S9. It seemed to me that the guy's implementation of the dual-Vee beam was working pretty well. But he also stated that the level of all the side and back lobes was sufficient that he didn't think he was going to put up a rotary yagi since he seemed to be able to hear (and work) just about anything that he heard anyone else work, such as the guys up north in the bay area. As Jerry, K0CQ indicated this morning in his posting about his modeling of the dual-rhomboid, the level of the minor lobes can be quite high; perhaps high enough to allow use of the antenna for coverage of more than just a single direction. Of course, it would be happenstance to find a minor lobe

actually fall in a particular direction you might want to cover in addition to wherever the main lobes might be. But consider that some of those minor lobes are only a few decibels below the main lobe. Thus, the gain of many of them is considerably above that of a dipole, turnstile or mini-loop such as those made by KB6KQ and M2. Consequently, it may be advantageous, in some circumstances, to consider a large rhombic or Vee beam with the understanding that you will have very poor control over where all the minor lobes wind up; but it could give you more gain in additional directions (remember, too, that those minor lobes will also pick up additional "noise" sources which may make the antenna WORSE than even a 10-element CC...).

Just a few comments that appeared regarding the articles in the December 1996 and March 1997 QST “World Above 50 MHz”. I thought it was rather interesting reading after having read the initial articles and saw these on the Reflector. Any RMVHF+ subscriber feedback is more than welcome on this antenna subject or any other subject. As with all “public domain” e-mail comments, the author’s get a copy of this issue for their scrapbooks - N0POH

VHF+ APRIL 1997 PAGE 9

NEW SMIRK REFLECTOR This reflector deals with any questions about the SMIRK Klub and the SMIRK Web site, or to make skeds with other SMIRK members. You can use the reflector to help new hams obtain information about six meter operations. Discuss 6 meter equipment, modifications, or antenna design. Or pass on any DX or QSL information be it new or old. To subscribe send email to: Majordomo@qsl.net no subject In message: subscribe smirk "email address" 73's George and Lisa N0EOQ KA0NNO http://www.cswnet.com/~ka0nno/ SMIRK HOMEPAGE http://www.cswnet.com/~ka0nno/page3.html#SMIRK HOMEPAGE

Bahama’s On 6 and 2 I am leaving for the Bahamas on June 5 for FL16. I will be there for 15 days this year. Last year I had 2200 QSOs on 6 and 2 meters. I was very surprise how many people needed me for a new country. I sent out over 800 QSL cards from that trip. While there I hope to install a 6 and 2 meter beacon. It is being built by Earl W8MGJ. They will run about 1 1/2 watts each and the call will be C6AFP. I receive the call C6AIE again. QSL info is to WZ8D with a S.A.S.E. Anybody that can donate a 6 meter ringo or a small 4 or 5 element 2 meter beam for the beacons that would be a great help. -- John Walker 1930 Meredith Dr. Loveland Ohio 45140 WZ8D EM79 160m-1296

Are you doing something unique in the weak-signal world? Is there something you've built or designed or done on the air that you can't wait to share with others? Something "cutting edge"? Tips for newbies? If so, CQ VHF magazine wants to make you famous! We are always interested in feature articles about weak-signal communications and all other VHF/UHF activities. If you've got something to share with a group of readers who span the spectrum from newly-licensed amateurs to old-time hams with more than 25 years' experience, I'd love to hear from you. (Please pass this on to others as well) You may download CQ VHF's writers' guidelines from the magazine's World Wide Web site at "http://members.aol.com/cqvhf/" or contact me via e-mail at "CQVHF@aol.com". If you don't have e-mail or web access, you may write to CQ VHF, 76 North Broadway, Hicksville, NY 11801 USA. (CQVHF has a little something for almost everyone. For those who are tired of a strict diet of QST and the mostly world of HF that they tend to cover you may wish to look at CQVHF - They’ve thought rather highly of RMVHF+ too! W&J)

Ham Radio Excluded from CB Enforcement Bill

ARLB021

At the request of the ARRL, Amateur Radio has been specifically exempted from a bill submitted April 17 by US Sen Russell Feingold (D-Wisconsin) that would give states and municipalities authority to enforce the FCC's CB regulations. Feingold's bill, designated as Senate Bill 608, originated with efforts by the Beloit, Wisconsin, City Council--responding to long-standing CB interference complaints--to pass an ordinance allowing local authorities to enforce FCC regulations. The bill is aimed at reducing radio frequency interference stemming from the use of unauthorized equipment or frequencies by CBers. In presenting his bill, Feingold told his Senate colleagues that he has received RFI complaints over the past several years from numerous Wisconsin communities ''in which whole neighborhoods are experiencing persistent radio frequency interference.'' If approved by Congress, Feingold's bill would amend the Communications Act to allow state or local governments to enforce regulations that prohibit the use of CB equipment not authorized by the FCC (such as high-power linear amplifiers). As it now stands, no license is required to operate on the 11-meter Citizens Band, but the FCC does have strict requirements on the type of equipment that CBers can legally use. Feingold's bill would preserve the federal preemption of all other telecommunications matters. It would exclude FCC-licensed services, including Amateur Radio, from state or local oversight. Also at the ARRL's request, the bill calls upon the FCC to provide ''technical guidance'' to states and municipalities in detecting and determining violations. Those affected by a state or local enforcement decision would be able to appeal to the FCC. ARRL asked Feingold to add this provision as final safeguard for amateurs who might be erroneously prosecuted despite the bill's other exemptions for amateurs. Feingold's bill also would not preclude the FCC from enforcing its own regulations as they apply to CB. Feingold called his bill ''a common-sense solution to a very frustrating and real problem which cannot be addressed under existing law.'' NNNN

CQVHF Looking for Weak Signal Articles... Rich Moseson W2VU

feature for the May issue. As we’ve mentioned elsewhere, we really hope our biggest feature for May is YOUR CONTEST Plans! Also, if anyone is planning on adding VHF+ capability to any Field Day outings please pass that along. I’ve worked 1D on CW for the past few years just to get those extra points to those who want to ask for them. For the No-Coders in the crowd, don’t be afraid to practice your Morse on the bands that you are licensed for. I have never really been able to figure the origin of the “unwritten rule” that says that No-Code Technicians are forbidden to use code in bands 50 MHz and above. No Code Technicians are licensed for ALL PRIVILEGES above 50 MHz. Recently, Dave W6OAL mentioned the possibility of a CW net here on the front range on 2 meters. I’ll sign up! please keep in mind I’m at about 6 to 8 wpm and tend to space a few characters out every once in a while, but practice makes perfect. I’ve completed more than one contest QSO with a key when nothing else would do. Well maybe it shows, I’m spending 20 to 30 minutes a day listening and practicing. Meanwhile, we really would like to encourage your feedback. We’ve lost a few subscribers lately, are we in danger of losing your support because we don’t know what you want to see in Rocky Mountain VHF+ ??? Please take a few minutes to drop us a note, give us a call or e-mail to let us know if we’re on the right track for you or not. We know a few have dropped by the wayside because of the current conditions on the bands or their current availability to operate. Hopefully, we’ll see them back as the SUN Spots return for the next Solar Cycle… 73 y we’ll see you on the bands… N0POH y KB0YRX

We can now predict the RMVHF+ cycle. It gets pretty barren between the September Contest and the January Contest. Then between the January Contest and the first day of Spring. At least for this sunspot cycle that’s been the case. Most everyone’s comments ended up in the activity reports because most of them dealt with real activity. We’ve run a few things this month that were on hand and I felt they were both timely and worthwhile. I was very thrilled to see the CB exemption and the CB enforcement bill announcement from ARRL. My neighbors and I have had repeated interference from CB linears that are used by a group of high school age kids. They get a big kick out of high power. If they didn’t swear so much on the air I might be inclined to try to introduce them to Amateur radio, but for now, I hope I can start eliminating some of the interference caused by the amps in these guys vehicles. We’ve still got a glitch or two in the computers here. They have eaten two copies of dB or Not dB part 3. I suspect that it’s a glitch with Publish97 and it’s translator for Word 6.0. We’ll resume Ron’s series in May. Also on tap, for those who may be trying to whip up a transverter for 2304 with a little help from Don N0UGY’s article from March, how about an antenna? Don handed me a disk with How to Build a Yagi for 2304 while at the LARCfest. That will be our

VHF+ APRIL 1997 PAGE 10

By Letter - By Phone - By E-mail - BY Packet -

On the Air

NETS

SUNDAY MORNING 8:30 AM MOUNTAIN TIME WSWSS on 3.940mhz , net control is KB6KQ in Carson City Nevada,

MONDAY NIGHTS

7 PM Mountain Time - Weak signal VHF Group 3843 kHz 7 PM Mountain Time - The Colorado ARES NET meets on 144.220.

7:30 PM Mountain Time - The New Mexico NET meets on 144.200 7:30 PM Mountain Time - “Friends on Two” net meets Colorado Front Range Horizontal and Verticle. Rag Chew and local info. Dave W6OAL Net Control

8 PM Mountain Time - Rocky Mountain VHF+ meets on 144.220

ACTIVITY NIGHTS

Tuesday 8 PM Local - 222.1

Wednesday 8 PM Local - 432.1

Thursday 8 PM Local - 1296.1

5

VHF+ APRIL 1997 PAGE 11

1997 Activity Calendar April 30 432 MHz Sprint (7-11 PM Local) May 10 902 MHz Sprint(7-11 PM Local) May 10 1296 MHz Sprint(7-11 PM Local) May 10 2304 MHz Sprint(7-11 PM Local) May 17 PPARA Swapfest Doherty HS 4515 Barnes Rd Colorado Springs, CO Doors open at 8:00AM KB0REI Carlos 719-632-1569 or Email Ccaro@ccs.lmco.com May 17-18 50 MHz Sprint (2300Z to 0300Z) May 31 Northern Colorado Hamfest Larimer County Fairgrounds June 14-16 ARRL VHF QSO Party June 28-29 ARRL Field Day August 2-3 ARRL UHF Contest August 16-17 ARRL 10GHz Contest August 23-24 Mountain ARC Campfest Woodland Park CO 4 mi N on Hwy 67 Talk in 146.82(-) Contact Don AA0NW (719) 687-3692 September 13-15 ARRL VHF QSO Party September 20-21 ARRL 10GHz Contest September 28 BARCfest Boulder County Fairgrounds Portions of this list courtesy of West Coast VHFer

signals from places that were beyond the range of most tropo openings. On 2M I heard many stations from DN70 (CO) to FN55 (ME) and all points in between, and was able to get solid QSO's in new grids using 150W and an 18' M^2 yagi at 5'. My 2M contacts were: 0110Z KO8Y EN57 0117Z VE3CWJ EN96 0135Z VE3VHB FN24 0218Z K0GU DN70

I also made 222 AU contacts with the ever-present K2YAZ (0139Z, EN74) and with W0ZQ (0204Z, EN34). I did manage one 432 AU contact, with K2YAZ right after our 222 contact, and heard KA0RYT (EN34) LOUD! on 432.1 trying to work some other stations. On 432, K2YAZ had a 55A signal, but it was 2.4 kHz up from my freq, presumably due to a 1.2 kHz doppler shift each way. I just barely heard Bob at first, with my RX tuned to my TX freq and using the standard CW filter on my FT 736. If I had been using the narrow CW filter, or even an audio filter, I would have completely missed the contact. Gotta remember to use that RIT knob when chasing AU on the higher bands! 73 & DX Jim - WB9SNR

Aurora was lots of fun with stations from FN65 to EN31, and north to EN66 and EN35 worked easily. Very little from any grids to the south. Even KE8FD in EM89 was more tropo than au! Worked two stations in FM19 at the height of the aurora on tropo - no buzz on the sigs with the antenna north and had to swing the array southeast to complete. Spent much of the time calling CQ and listening with the antennas far west looking for Dakotas/Nebraska(and 7's!!)but to no avail. Nice to hear relatively rare Rhode Island now well represented by K1ZE. Biggest signal award goes to K8BHZ - Brian, I know you're not too far from here, but you were LOUD! Swore at times I was back in the early 70's with K0MQS, W0LER, and WB9SNR on the band (144 Mhz). Almost got my wife Heather out to the shack so we could activate VE3EMS! -- 73, Peter Shilton VE3AX (ex-VE3VD, VE3EMS)

(Your feedback would be appreciated if you like to see what others did while you got your’s or as in my case and others, while we missed out. You want more or less? Please let us know! W&J)

VHF+ APRIL 1997 PAGE 12

Newsletter out of Minnesota) "I think the ARRL CAC will be reviewing the "new rover rules" soon. They said they would review them in two years. Well it's been almost two years" You know, I had forgotten that! "Now there is NO WAY that a ham from the Upper Midwest could win (Roving), unless you had huge rates and only roved in two grids. I don't call that roving." Rich's quote, which represents not only his area, but the Rocky Mountain West as well as MOST of the rest of the COUNTRY outside of the populated EAST and WEST COASTS... Copies of this month's Rocky Mountain VHF+ will be sent to some selected non-subscribers, as a

I recently received my first exchange copy of Great Lakes VHF/UHF. A nice regional newsletter published by Dave Bostedor Jr. N8NQS. One of the lead articles was ARRL Contest Rover Scoring Rules (Sour Grapes -or- Legitimate Gripes). In it were reminiscences of those who rove, comparing the NEW Scores with the venerable OLD rules. My First thought was "I thought we'd already beat this one to death…” until I caught the words of Rich N0HJZ. (Rich, until recently, published a regional VHF/UHF

reminder that Rocky Mountain VHF+ is an ARRL affiliated contest club and the area between the seacoasts needs to get a little more than lip service from the organization that represents the amateurs of the United States. CAC, take a look at Rover Rules and a little more land mass than the populated coasts. We too are dues paying ARRL members. 73 from the editor Wayne Heinen N0POH