test ic910h

Product Review & Short Takes Columns from QST Magazine

Copyright © 2000 by the American Radio Relay League Inc. All rights reserved.

Month YearProduct ReviewsICOM IC-910H VHF/UHF Multimode Transceiver

DB6NT MKU 10 G2 10-GHz Transverter Kit

Short TakesN4PY Pegasus Control Program, version 1.45

From May 2001 QST © ARRL

Joe Bottiglieri, AA1GW Assistant Technical Editor

PRODUCT REVIEW

Bottom Line

The ICOM IC-910H offers a greatselection of capabilities and featuresfor the VHF/UHF enthusiast. Its mul-tiple modes and ample power output—and optional 23-cm coverage—make ita versatile tool for FM, weak-signalterrestrial and satellite operation.

Reviewed by Steve Ford, WB8IMYIt’s easy to pigeonhole the IC-910H

as a “satellite transceiver,” but that wouldbe a mistake. This radio offers a rangeof versatility—not to mention a hefty100 W output on 2 meters and 75 W out-put on 70 centimeters—that makes it atruly multipurpose rig.

The IC-910H is disarmingly compactat only 91/2 × 311/16 × 913/32 inches. Despiteits size, all of the front-panel controls andswitches are ergonomically placed foreffortless operation (even with big fingerslike mine). The VFO knob is large andits rotation is smooth. The expansive LCDdisplay is easy on the eyes and readablefrom every angle. Since the IC-910H is adual-band radio (actually, it’s triband ifyou purchase the 1296 MHz module), youhave separate RF/AF gain and squelchcontrols on the front panel. The micro-phone and headphone jacks are on thefront panel as well. (A small hand mikeis included.)

Turn the radio around and you findantenna jacks for 2 meters and 70 centi-meters (installing the optional UX-9101296-MHz module adds a third antennajack). There are three accessory sockets,two data jacks for digital communication,a pair of external speaker jacks, the obliga-tory dc power connector and an interfacejack for computer control. All in all, it isa clean, uncomplicated layout.

The IC-910H as Terrestrial SSB/CWTransceiver

The IC-910H is an exceptional tool forexploring the mysteries of the so-called“weak signal” modes. The convenienceof being able to jump back and forth be-tween bands is something that could spoilme in a heartbeat. The IC-910H displaysboth the “main” and “sub” band frequen-cies vertically (main on top, sub below)along with bargraph-style signal-strengthindicators in each section. You can re-ceive simultaneously on both bands, butyou can transmit from the main band only(this arrangement is reversed when youare in the satellite mode). Of course, aquick press of the button flips the main/sub frequency assignments. The ’910Hhas two VFOs for each band. You can optto use the main VFO knob to make fre-quency changes on either the main or subbands—or assign the RIT or IF SHIFT

ICOM IC-910H VHF/UHF Multimode Transceiver

knobs to function as the sub band VFOcontrol (clever!). You can even punchyour chosen frequencies in directly fromthe front-panel keypad.

I used the ’910H primarily to huntcontacts on 2 meters and 70 centimeters.Even with my puny att ic-mountedYagis, the range was impressive. SSBcontacts spanning 150 miles were notuncommon on 2 meters. During a briefband opening on 70 centimeters, I en-joyed an SSB contact on 432.1 MHz overa distance of about 100 miles. With out-door antennas, low-loss coax and receivepreamps, I’m confident that my commu-nicating range would have been consid-erably greater.

On 1296 MHz I set up a couple ofskeds with a local station just to see howthe IC-910H played on this band. Reportson my transmit signal were very favor-able, and the local station that I was com-municating with sounded good as well.The overall lack of activity on the bandin my area and my less than optimal an-tenna (a small helical) gave me less suc-

cess with unscheduled contacts than I hadon the other bands.

IC-910H as FM TransceiverThe IC-910H is a fully capable FM

transceiver. The considerable outputpower on 2 meters and 70 centimetersgives the radio a formidable punch on FMsimplex. For repeater operation the ’910Hoffers most of the same conveniencefunctions you find on many mobile FMrigs. The duplex offset frequencies areprogrammable for each band. There is a50-tone subaudible (CTCSS) tone en-coder/decoder for use with repeaters thatrequire the tones for access. The stockmicrophone, however, does not include aDTMF pad for control or phone patchapplications.

Testing the ’910H on FM was an idealopportunity to experiment with thememory and scanning functions (al-though these functions are available forother modes as well). The IC-910H sports106 memory channels—99 regular chan-nels, 6 scan-edge channels and one callchannel for each band. The memory chan-nels can be programmed with the fre-quency, mode, simplex or duplex andsubaudible tone frequency. Alphanumericmemory naming is not supported.

There’s also 5 (or 10—your choice)“Memo Pad” memories. These are veryhandy for temporarily storing interestingfrequencies. This storage system is set upas “first in, first out.” When you program inthe sixth (or 11th) frequency, the first fre-quency that you memorized will be erased.


Memory programming is straightfor-ward and probably familiar to most FMoperators. You can transfer VFO contentsto a memory channel, or vice versa. Thecall channels are convenient memoryslots to store a single frequency (or fre-quency combination) for each band thatyou use often. To access one of these, yousimply push the MS/BAND button to se-lect the desired band, then press the CALLbutton.

There are three scanning modes in theIC-910H: memory scan, programmed scanand mode-select scan. The memory scan,as the name suggests, scans through thememory channels, automatically exclud-ing blank, call or scan-edge channels. A“memory channel lockout” feature, fortemporarily excluding a specific memorychannel from a scan, is not included. Thescan resume conditions (what happens af-ter the scan stops on a busy channel) andthe scan speeds are selectable. In the pro-grammed scan mode, the ’910H scans inthe VFO mode between the two frequen-cies programmed in the scan-edge memorychannels. Mode-select scan is intriguing.It allows you to scan through only thosememory channels that are programmedwith a particular mode (FM, SSB or CW).For example, you can set up the ’910H toscan only your SSB “hot spots” if that isyour interest at the moment!

I’ve already mentioned that theIC-910H can generate subaudible tonesfor repeater access. As it turns out, thetone-scan function allows you to detectthese tones as well. If you don’t know thefrequency of the subaudible tone in useon a particular repeater, the ’910H canscan the incoming signal and alert you tothe exact tone frequency. In fact, you canconfigure the transceiver to activate itsown tone squelch function. In this mode,the ’910H remains silent until the propersubaudible tone is received.

Related to the various scanning func-tions is the IC-910H’s simple band scope.This feature allows you to sweep bothsides of a center frequency to check foractivity. Detected signals are displayedas part of the signal-strength indicator foreach band. This feature is available forSSB as well as FM.

IC-910H as Satellite TransceiverDespite the versatility of the ’910H,

its use as a satellite transceiver garnersthe most attention in the amateur com-munity. Considering the innovative sat-ellite-operating features this rig provides,this is easy to understand. I’d be less thanhonest if I said that I wasn’t eager to trythe ’910H on the satellites as quickly aspossible.

I put the IC-910H to work primarilyon the Fuji-OSCAR 29 and 20 satellites

because these birds operate in Mode J—listening on 2 meters and retransmittingon 70 centimeters. In addition, both sat-ellites use inverting transponders. What-ever you transmit on the uplink is invertedon the downlink—LSB on the uplink be-comes USB on the downlink; a signal ata frequency in the lower portion of theuplink passband appears at the upper por-tion of the downlink passband. Add theconsiderable Doppler frequency shiftthat’s present on the 70-cm downlink andyou have the potential for serious opera-tor confusion. (A condition that may alsoexist on the new AO-40 satellite—it usesinverting transponders.) The IC-910Hpromises features to alleviate the head-aches. Does it deliver?

Prior to my first Fuji-OSCAR attemptwith the ’910H, I set the downlink fre-quency on the main band at 435.900MHz—the top end of the downlink pass-band. I entered the uplink frequency in thesub band at 145.900 MHz, which is thebottom end of the uplink passband. Byswitching to the satellite mode and en-abling reverse tracking, I was ready to go.It’s worth noting that the ’910H includes10 separate satellite memories that youcan preprogram with all the necessarysetup information for your favorite birds.

When OSCAR 20 rose above 10 de-grees elevation, I was able to hear the CWbeacon clearly with my attic Yagis. I be-gan tuning up through the downlink pass-band and watched as the ’910H’s uplinkfrequency stepped downward automati-cally in perfect sync. Despite that fact thatI wasn’t using a receive preamplifer, I wasable to eavesdrop on several SSB conver-sations without difficulty.

A quick phone CQ brought a responseand a 59 report. Doppler shift on the 70-cm downlink was tricky, but the IC-910’sautomatic reverse VFO tracking made iteasy to compensate. I didn’t have to re-mind myself to raise my uplink frequencyto compensate for Doppler shift on thedownlink.

And even with my mediocre antennas,the ’910H provided more than enoughoutput for my signal to be heard throughthe satellite. In fact, I often discoveredthat I was a little too strong. (The rule ofthumb is that your own signal on thedownlink should be roughly equal instrength to the satellite’s CW beacon.)Thankfully, the ’910H’s output is adjust-able all the way down to 5 W.

Digital satellite enthusiasts will bepleased to hear that ICOM has paid par-ticular attention to data communication inthe IC-910H. As you can see in the ac-companying ARRL Lab test results, thebit-error-rate (BER) performance of the’910H was impressive. Using a 9600-baudmodem and WiSP software, I was able to

consistently grab large amounts of dataduring two KITSAT-OSCAR 25 passes.

IC-910H as Contest TransceiverIf the ’910H performs well for terres-

trial weak-signal and satellite work,would it perform just as well during acontest?

If your contesting interest is more thancasual, this transceiver may disappoint.In fairness, however, the IC-910H is notdesigned to be a competitive contestradio, and it would be unreasonable tocompare it to, say, a VHF/UHF conteststation based on high-performance trans-verters. The dynamic range performanceon 2 meters and 70 centimeters wasn’tadequate to deal with numerous nearbysignals. I set up a contest simulation witha couple of stations and it quickly becameclear that the ’910H wasn’t up to the taskof sorting through the chaos (even withjudicious use of the IF SHIFT control andRF attenuator).

It is important to note that our Labtests revealed that the IC-910H generateda substantial amount of phase noiseon all bands. In casual applications,this would not be a problem. Unlike HFphase noise, these signals would nottravel very far. However, if you were us-ing the IC-910H in a multioperator con-test environment, the transceiver has thepotential to create a fair amount of inter-ference to the other radios, depending onthe bands and frequencies in use.

Additional HighlightsICOM has also packed in some fea-

tures that you may not expect to find in aVHF/UHF transceiver. Some examplesare VOX, a sideband speech compressorand a variable attenuator. A speech syn-thesizer—the UT-102 is available as anoptional accessory. This will announcethe current operating frequency and mode(and the S meter reading, if desired) atthe push of a button. Optional DSP noisereduction boards can also be installed.Separate UT-106 DSP units can be addedto the main and sub receivers.

There’s even a built in CW keyer. Thekeying speed is adjustable from about 6to 60 WPM, and you can vary the break-in delay time, the weighting, the paddlesense, the pitch and the side tone level.In a pinch, you can use the UP/DOWNbuttons on the microphone for sendingCW.

ConclusionWith a decent antenna system, feed

line and preamp, the IC-910H has thecapability to be a worthy contender forpoint-to-point terrestrial communicationon SSB and CW in noncontest environ-ments. On FM its power and features


Table 1ICOM IC-910H, serial number 01242Manufacturer’s Claimed Specifications Measured in the ARRL LabFrequency coverage: Receive, 136-174, 430-450, 1240-1300 MHz;1 Receive and transmit, as specified. transmit, 144-148, 430-450, 1240-1300 MHz.1

Power requirement: Receive, 2.5 A; Receive, 1.5 A; transmit, 21.5 A. Tested at 13.8 V. transmit, 23 A (max output). 11.7-15.9 V dc (13.8 V nominal)Modes of operation: SSB, CW, FM. As specified.

Receiver Receiver Dynamic TestingSSB/CW sensitivity, bandwidth not specified, Noise floor (MDS), 500 Hz filter: 10 dB S/N: <0.11 µV. 144 MHz –141 dBm

432 MHz –142 dBm1240 MHz –144 dBm

FM sensitivity, 12 dB SINAD: <0.18 µV. For 12 dB SINAD:146 MHz 0.13 µV440 MHz 0.14 µV1240 MHz 0.17 µV

Blocking dynamic range: Not specified. Blocking dynamic range, 500 Hz filter:144 MHz 106 dB*432 MHz 104 dB*1240 MHz 92 dB*

Two-tone, third-order IMD dynamic range: Not specified. Two-tone, third-order IMD dynamic range, 500 Hz filter:144 MHz 85 dB*432 MHz 80 dB1240 MHz 78 dB*

Third-order intercept: Not specified. 144 MHz –6.4 dBm432 MHz –5.8 dBm1240 MHz –14.5 dBm

FM adjacent channel rejection: Not specified. 20 kHz channel spacing: 146 MHz, 66 dB; 440 MHz, 73 dB; 1240 MHz, 51 dB.

FM two-tone, third-order IMD dynamic range: Not specified. 20 kHz channel spacing: 146 MHz, 66 dB*; 440 MHz, 73 dB*; 1240 MHz, 51 dB*; 10 MHz channel spacing: 146 MHz, 93 dB; 440 MHz, 85 dB; 1240 MHz, 65 dB.

S-meter sensitivity: Not specified. S9 signal: 146 MHz, 25 µV; 432 MHz, 14 µV; 1240 MHz, 11 µV.Squelch sensitivity: SSB, <1.0 µV; FM, <0.18 µV. At threshold: SSB, 144 MHz, 0.58 µV; FM, 146 MHz, 0.14 µV;

440 MHz, 0.10 µV; 1240 MHz, 0.09 µV.Receiver audio output: 2.0 W at 10% THD into 8 Ω. 2.8 W at 10% THD into 8 Ω.IF/audio response: Not specified. Range at –6 dB points, (bandwidth):

CW-N (500 Hz filter): 358-1123 Hz (765 Hz); CW-W: 147-3084 Hz (2937 Hz); USB-W: 129-2887 Hz (2758 Hz); LSB-W: 148-3098 Hz (2950 Hz).

IF and image rejection: 144, 430 MHz, 60 dB; 1240 MHz, 50 dB. First IF rejection, 144 MHz, 91 dB; 432 MHz, 99 dB; 1240 MHz, 126 dB*; image rejection, 144 MHz, 85 dB; 432 MHz, 86 dB; 1240 MHz, 99 dB.

Transmitter Transmitter Dynamic TestingPower output: 144 MHz, 100 W high, 5 W low; 144 MHz, typically 96 W high, 1.1 W low; 430 MHz, typically 430 MHz, 75 W high, 5 W low; 1240 MHz, 10 W high, 1 W low. 73 W high, <1 W low; 1240 MHz, typically 10 W high, <1 W low.Spurious-signal and harmonic suppression: 144 MHz, 68 dB; 430 MHz, 71 dB; 1240 MHz, 71 dB. 144, 430 MHz, ≥60 dB; 1240 MHz, ≥50 dB. Meets FCC requirements for spectral purity.SSB carrier suppression: ≥40 dB. As specified. >40 dB.Undesired sideband suppression: ≥40 dB. As specified. >47 dB.Third-order intermodulation distortion (IMD) products: Not specified. See Figures 1, 3 and 5.CW keying characteristics: Not specified. See Figure 7.Transmit-receive turn-around time (PTT release to S9 signal, 70 ms. 50% audio output): Not specified.Receive-transmit turn-around time (tx delay): Not specified. SSB, 32 ms; FM, 32 ms. Unit is suitable for use on AMTOR.Composite transmitted noise: Not specified. See Figures 2, 4 and 6.Bit-error rate (BER), 9600-baud: Not specified. 146 MHz: Receiver: BER at 12-dB SINAD, 7.4×10–4; BER at

16 dB SINAD, 1.1×10–5; BER at –50 dBm, <1.0×10–5; transmitter: BER at 12-dB SINAD, 1.5×10–3; BER at 12-dB SINAD + 30 dB, <1.0×10–5.440 MHz: Receiver: BER at 12-dB SINAD, 7.1×10–4; BER at 16 dB SINAD, 1.7×10–5; BER at –50 dBm, <1.0×10–5; transmitter: BER at 12-dB SINAD, 1.6×10–3; BER at 12-dB SINAD + 30 dB, <1.0×10–5.1240 MHz: Receiver: BER at 12-dB SINAD, 9.4×10–4; BER at 16 dB SINAD, <1.0×10–5; BER at –50 dBm, <1.0×10–5; transmitter: BER at 12-dB SINAD, 1.7×10–3; BER at 12-dB SINAD + 30 dB, <1.0×10–5.

Size (HWD): 3.7×9.5×9.4 inches; weight, 10 pounds.Note: Unless otherwise noted, all dynamic range measurements are taken at the ARRL Lab standard spacing of 20 kHz.*Measurement was noise-limited at the value indicated.Third-order intercept points were determined using S5 reference.1With the optional UX-910 1200 MHz Band Unit.


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Figure 1—Spectral display of the IC-910Htransmitter during two-tone inter-modulation distortion (IMD) testing on2 meters. The worst-case third-orderproduct is approximately 27 dB belowPEP output, and the worst-case fifth-order product is approximately 51 dBdown. The transceiver was beingoperated at 100 W output at 144.2 MHz.

Figure 3—Spectral display of the IC-910Htransmitter during two-tone inter-modulation distortion (IMD) testing on70 cm. The worst-case third-order productis approximately 23 dB below PEP output,and the worst-case fifth-order product isapproximately 41 dB down. Thetransceiver was being operated at 75 Woutput at 432.2 MHz.

Figure 7—CW keying waveform for theIC-910H, showing the first two dits usingexternal keying. The equivalent keyingspeed is 60 WPM. The upper trace is theactual key closure; the lower trace is theRF envelope. The transceiver was beingoperated at 100 W output at 144.02 MHz.

Figure 2—Spectral display of the IC-910Htransmitter during composite noisetesting on 144.02 MHz. Power output is100 W. The carrier, off the left edge of theplot, is not shown. This plot showscomposite transmitted noise 2 to 22 kHzfrom the carrier.

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Frequency Sweep: 2 to 22 kHz from Carrier

Reference Level: - 60 dBc/HzVertical Scale: dBc/Hz

Figure 5—Spectral display of the IC-910Htransmitter during two-tone intermodula-tion distortion (IMD) testing on 23 cm. Theworst-case third-order product is approxi-mately 25 dB below PEP output, and theworst-case fifth-order product is approxi-mately 38 dB down. The transceiver wasbeing operated at 10 W output at 1240.2 MHz.

Figure 6—Spectral display of theIC-910H transmitter during compositenoise testing on 1240.02 MHz. Poweroutput is 10 W. The carrier, off the leftedge of the plot, is not shown. This plotshows composite trans-mitted noise 2 to22 kHz from the carrier.

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Figure 4—Spectral display of theIC-910H transmitter during compositenoise testing on 430.02 MHz. Poweroutput is 75 W. The carrier, off the leftedge of the plot, is not shown. This plotshows composite transmitted noise2 to 22 kHz from the carrier.

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make the ’910H the clear choice for ei-ther voice or data communication. Forsatellite operating, the IC-910H has al-ready taken its place among the elitetransceivers for its power and ease of use.

I had only one nit to pick with theIC-910H—and it is a nit this radio shareswith many other rigs in its class. As a hamwho would like to explore the higher mi-crowave bands (especially on the newAMSAT-OSCAR 40 satellite), I plan touse transmit and receive converters. Withthat in mind, I would love to see: (A) alow-power (1 W or less) output port onthe rear panel to drive a transmit converterand, (B) the ability to select alternate fre-quency displays that would show the ac-tual frequency being received rather thanthe frequency of the IF transceiver. Inother words, when I am listening to anS-band downlink signal from AO-40, Iwould prefer to see the 2.4 GHz fre-quency on the ’910H display, not the2-meter frequency my receive converteris supplying. These may seem like nig-gling requests, but they make a substan-tial difference in operating ease and con-venience for satellite operators andterrestrial microwave enthusiasts.

Manufacturer: ICOM America, 2380116th Ave NE, Bellevue, WA 98004;425-454-8155; fax 425-454-1509;[email protected]; www.icomamerica.com. Manufacturer’s sug-gested list price: $1799. Typical currentstreet price: $1450.

Manufacturer’s suggested list pricingfor selected optional accessories: CR-293high stability crystal unit, $380; CT-17level converter (for computer control),$169; FL-132 500 Hz CW filter (mainband), $133; FL-133 500 Hz CW filter(sub band/satellite), $133; UT-102 voicesynthesizer, $74; UT-106 DSP unit, $166;UX-910 1200 MHz Band Unit, $599.

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