ICOM IC-761 HF transceiver
Manufactured: Japan, 1987-1989 (Discontinued)
ICOM's IC-761 is Ihe latest HF entry from I the Land of the Rising Sun. It is a fully solid state, digital displayed, highly sophisticated radio communications device, I know those are not words normally used to describe a piece of ham radio equipment, but the 761 is no plain piece of ham radio gear. It is the most precision-crafted and complete ham transceiver from ICOM to date.
The IC-761 is larger than the Kenwood TS-940. and is black. It is solid in appearance and feel, with a formidable 69-control front panel. It rounds itself out with memory functions, a built-in antenna tuner, full break-in keying, electronic keyer, and high-stability crystal unit. Naturally, the 761 can be used as a very effective short wave receiver. It can also be remotely controlled by computer via an RS-232C/seria I-port connection.
The instruction manual that comes with the 761 is the best laid out manual I have seen in several years. Replete with pictures, diagrams, and easy-to-understand explanations of each individual control, it is as much state of the art as is the transceiver itself.
With a rig as sophisticated and complicated as this one, I needed to completely review the manual before any on-the-air operation was done.
The smooth weighty feel of the tuning dial is impressive (and adjustable) giving the feeling of total control. This is a welcome improvement over other manufacturer's radios. The digital readout is very nice, with no background flicker during tuning, and easy-to-read large blue numbers. Additionally, the memory numbers (and some of the other information that appears on the display) are in red. No confusion here.
I do wish, however, that there was 10 Hz readout This is available by switch selection (or internal modification) on many other contemporary HF transceivers,
The tuning rate is adjustable from 5 to 500 kHz per turn. Under ordinary circumstances the user will be tuning at the rate of 5 kHz per turn of the dial If the dial is turned at a fast rate, the tuning rate picks up to 25 kHz per turn. If the ts button is pushed, you clip along at 500 kHz per turn. I thought this was a change from some of the earlier ICOM transceivers, so I did some checking. The 751A tunes at 2 kHz per turn in slow speed, and the venerable 730 tunes at 1 kHz per turn. I like the slower tuning rates better; however, the large tuning dial of the 761 makes for easy tuning.
The digital keypad, used for direct frequency entry, has excellent tactile and audio feedback, You push a button, and know you did, not think you did.
With the advent of all the solid state radios over the past few years. I think everyone knows all about passband tuning and i-f shift. The 761 has both, and they perform as expected. They share a common control that is de-tented for the zero point. In addition to these tunable receive features, there is a filter switch that allows switching to alternate fitter schemes.
The memory feature is particularly nice in that when a memory frequency is selected, you can immediately tune away from it by turn* ing the main tuning dial To return, merely push the memo button.
The notch filter works very well, allowing easy night operation on 40 meters, It is a deep notch, however; very sensitive to tuning.
I tuned in the local country-western station on AM and listened to it. The audio quality was excellent. It makes a nice change after you've been in a few pileups with the Saturday after* noon kilowatt bunch.
The quality of the receive audio from the built-in speaker compares favorably with my main station speaker. It is not tinny sounding.
There is a tone control for base and treble. There is not a large amount of variation, but enough to make a light voice sound more authoritative.
The receiver is very quiett and doesn't get overly excited by summer static. Background noise is almost nonexistent. I found the noise blanker capable of removing offensive woodpeckers and the garbage caused by a faulty florescent light in my laundry room.
Scanning is possible, with several modes to select from. I found that scanning the 10-meter band was profitable when checking to see if the band was open and when looking for beacons. It was easy to scan the memories for activity on any of the several nets I operate on.
The 761 has two VFOs—really handy for working SSB splits. For CW splits, you can normally get by with the use of RIT (transmit). Split-band operation is possible with the 761.
The 761 is easily modifiable for use on odd-bait MARS frequencies, although many can be reached with the factory set up.
The keyer behaved wonderfully, and QSK is where it's at for the CW operators. I could find no fault when operating QSK, and could be broken with single dit. The note was approved of by all.
The monitor feature is a great adjunct when setting up your compression levels or testing various mikes for tonal qualities. Just put on the headphones and listen to your own voice.
Itls also possible to vary transmitted voice tones with a pot inside the 761. The pot can be preset to highlight highs or lows, at your choice.
The audio reports I received were interest-mg. Most indicated I had excellent audio, a couple stated I was overdriving the rig. Several contacts asked what amplifier I was running. Just remember, audio reports vary with the receiving operator's hearing and preference. Reports from stations knowing my voice were all positive.
The built-in antenna tuner got a poor workout here, as my antenna system is pretty well peaked up. However, I was able to give it a test on 80 CW by using the 75 phone antenna. It took only 2 to 3 seconds for the automatic tuner to do its work, and I was on the air again.
The relay used to key linear amplifiers is a little anemic. I recommend the use of an external keying relay. ICOM is not alone with this problem. I recommend an external relay for most of the current transceivers-Contrary to popular belief, a failure of the lithium memory backup battery will not place the entire transceiver off the air. It will only mean you cannot save and recall frequencies. Replacement does not appear to be a complicated matter.
Bench testing is the only true method of measuring performance of any of the currently
available amateur transceivers. I feel that all of them are capable of performing above and beyond the capabilities of the human ear, and certainly over the poor band conditions we often experience.
The following equipment was used in checking the performance of the IC-761: Leader LDC 8243 Frequency Counter Marconi Instruments 2022 Signal Generator Hewlett Packard 606 HF Signal Generator Hewlett Packard 651A Audio Generator Bird 43 Wattmeter
Hewlett Packard 8551B/851B Spectrum
Analyzer Cushman CE-5 Monitor Tectronics 475 Oscilloscope
The specificatons and test results of the rig are shown in the sidebar,
I could find no fault with bench operation of the 761, and found no place where the advertised specifications were not met or exceeded, Again, the rig is capable of outperforming many ears and conditions.
Not all the features of the iC-761 (or any other top of the line transceiver) will be of use to all operators, nor will the price be acceptable to everyone. However, feature for feature, the IC-761 is a most capable piece of equipment and is real competition for other top of the line transceivers. With the exception of the few faults I indicated in my observations, I feel comfortable in recommending the 761 as a good piece of equipment, albeit a little rough on the wallet.
Thanks to the folks at the Electronic Equipment Bank of Vienna, VA, for the loan of the IC-761. and the use of their very complete test bench.!
- Bill Clarke WA4BLC - 73 Amateur Radio 1987