Icom IC-7100

the little radio with big features…

© 2018 by KV5R. All Rights Reserved. Rev. 2/9/2019.

Icom IC-7100

Introduction

Ahhhhh, the li’l 7100… What can I say? I like it! It performs like big radio, but it’s small. It sounds good, and it’s well made. With its remote head, touch-screen, IF DSP, all-band all-mode (even D-Star), and built-in USB computer interface, it’s, well, about 20 years beyond my old 706MkIIG. It has an impressive list of standard features, like 0.5ppm TCXO reference oscillator, speech, SD card slot (to save/restore settings, record QSOs, etc.), three adjustable filter settings for each mode, an SSB DATA mode (for running all those computer soundcard digital modes), and, and, and… lots of other nifty stuff. The only thing it doesn’t have is a 1st IF mixer output for a panadapter—but it’s fairly easy to add one, and we will, in another article.

Decisions, Decisions

Why’d I get one, instead of the 7300? Well, I operate from bed nowadays, and I need that little remote head. I just can’t sit up to a desk for long periods anymore. And though I’m not really into VHF/UHF, or D-Star, it’s there if my interests change. Plus, I got it on sale for $860, and it’s a LOT of radio at that price! Even though it took three months to get the Icom rebate.

Prior to purchasing the 7100 (in November 2017) I spent several weeks reading the articles and user reviews on eham.net, qrz.com, and elsewhere. I carefully considered the reports of low SSB output, ticking noise, and failing touch-screens — early problems that were eventually fixed but last forever on the web. Many reviewers simply didn’t like the 45-degree control head, and the fact that it isn’t attachable. People tend to love it or hate it. One thing is certain, if you’re tied to the idea that a radio must be a rectangular box with a flat face, you won’t like the 7100—well, at least not at first. It isn’t a “pretty” radio like the big desktop models. It won’t impress your friends with a big colorful display or 20 knobs and 100 buttons. But after using it for a little while, the lack of “bling” just doesn’t seem to matter—it just works, it’s very easy to use, and takes up little space. And you can take the control head (up to 11 feet) to your bed or recliner, kick back, and not always be tied to a desk and chair.

I added an SDR panadapter (fed to my 32-inch TV/monitor), a 1kW amplifier, an 8-band EQ/compressor/noise-gate, and a dynamic vocal microphone on a boom, so it’s really not missing anything the “big-boy” radios have, except the high price tag.

First Impressions

Likes

There are many things to like about the 7100. Among them,

  • Sloping, detached control console: Finally, a radio face you can see without bending your neck or propping up the front of the radio. Put the radio body (and its gob of cables) out of the way, and put the control head where you need it. Since I operate from a supine position, I need the face angled forward, not back, so I screwed a little dash-cam mount into its ¼-inch camera socket and put it at the exact angle I need. But on a desk or in a mobile, the 45-degree face is just right. No more bending low to see the screen, and no more propping the radio upward. And the triangular cross-section of the control head provides room for a nice oval speaker inside, though I still prefer my old 8-inch dual-cone external speaker.
  • Touch screen: easy to use, intuitive, and functional. No deep-level menu system needed. Most items toggle with a short-press or two, and adjust with a long-press and a turn of the dial. The deepest menu is Set → Functions, where it goes three levels deep, and everything is labeled with plain language, not cryptic code numbers. If you’ve operated a 706 or 7000, the 7100 is much easier, even though it has many more settings.
  • Variable bandwidth digital IF filters: three per mode, and all can be changed with a long-press. It’s pretty sweet to tune a CW or PSK31 signal then dial it right down to 50Hz! Or on SSB, knocking out that incessant jibber at 3kHz. Also, in addition to three adjustable filters for SSB, there’s three for SSB-DATA mode, so you can set three for voice, and three for computer digital modes. There are also three transmit bandwidth filters, which may adjusted between 100 and 2900 Hz. Unfortunately, 2900 is the limit, so don’t expect to do “enhanced” (wide-band) SSB with this radio.
  • TCXO: High-stability temperature-compensated reference oscillator. Calibration is simple: there’s a setting called REF ADJUST in Set → Functions. Dial up WWV, read an audio beat frequency on the computer, and you can get it within ±0.2Hz, without even removing the cover. And being temperature compensated, it stays on frequency. It’s better than many test-bench frequency counters. Indeed, I calibrated it to WWV at 20, then dialed it up to 50 and calibrated the TCXO reference oscillator in my test-bench frequency counter.
  • DSP: The noise blanker, noise reduction, and notch filters work very well, with one exception: any nearby strong signals (in the roofing filter’s pass-band) will generate “splatter” in the noise blanker. Otherwise, it’s the first noise blanker I’ve seen that’ll knock out that nasty 60Hz power line grinding noise, not just impulse noise. The noise reduction (NR) works, but muffles the audio somewhat, and is best at no more than 4, like previous Icoms. There are two notch filters, Manual and Auto. The Auto Notch zaps multiple heterodynes, and may be left on all the time; it does not seem to color the audio. The Manual Notch works differently, it’s outside the AGC loop, and even though you have to set it manually, it’ll null a carrier and stop it from compressing your AGC. Very handy for reading a weak CW or PSK signal right next to a strong one.
  • Audio EQ: It has bass and treble for TX and RX and every mode. One could wish for a mid-range also, but it’s a lot better than nothing. The default 0 settings are somewhat muddy, so put the bass on 0-2 and the treble on 4-5 for both transmit and receive, as a starting point.
  • Built-in USB serial port and Soundcard interface: No more overpriced little interface box, USB adapters, and gob of cables. Download and install the driver, plug in the supplied USB cable, and select the new COM port and soundcard in your digi-mode software. It does take some time setting up both the radio and the computer, but if you’ve used a SignalLink or similar, it’s not much different. We’ll cover that in the next article.
  • Great AM, shortwave, and FM broadcast receiver. Great VHF/UHF scanner. 500 memory channels in 5 banks. When the ham bands are dead, there’s lots of other radio stuff to browse. It’s like having a ham transceiver with four more expensive receivers thrown in for free!

A Few Gripes

None of these are deal-breakers, just annoyances that should have been corrected well before the model’s 5th year. I believe that some of them are marketing inducements, little shortcomings designed to urge buyers on to more expensive models.

  • Low-resolution monochrome resistive-touch screen: Really? When you can get an $89 tablet computer with a 1920x1200 16.7-million-color capacitive-touch screen, there’s no excuse for Icom using a 320x240 monochrome display. Considering the 7000’s color display, it’s a step backwards. But even though you can see the dot-matrix pixels, it is very readable. The back-light adjusts from very dim to very bright, and there's also a contrast adjustment.
  • RJ-45 mic jacks: there’s plenty of room for the much stronger 8-pin Foster. The RJ-45 was never made to be pulled on with a coil-cord, and besides, making your own requires that expensive modular plug crimper tool. I can understand the modular plug on the thin 706 control head, but not on the considerably larger 7100.
  • The HM-198 stock hand mic: it’s too big, and sounds mushy. The HM-103 from my 706 sounds much better. Why didn’t they just stay with that winner?
  • Icom reverted to the “pre-Pro” high-level mic input and pre-amp mic. So, to use any non-Icom mic, you need a pre-amp. They probably did that to overcome crosstalk in the data cable.
  • The mini-B USB jack: tiny and flimsy. There’s room for the full-sized B jack, like the 7300 uses.
  • The two stacked knobs: they’re too small, and they wobble around. They work okay, but feel cheap. When turning the tiny volume knob, you have to be careful to not also turn the RF/SQL knob. The 706 had much better stacked knobs.
  • The 16 buttons: Poor design choices, 4 of them are for CW and contesting, while several much more often used ones are in the three on-screen menus, like VOX and Compression. Things rarely used, particularly on a mobile radio, should be in menu settings, not physical buttons. It looks like marketing said, “We gotta put some buttons on the panel for every possible buyer,” ignoring the fact that typical users will use VOX and COMP 10,000 more times than RIT and XFC. But they put VOX and COMP on screen menus (M1-M3), so you have to push Menu button 1-3 times then push the screen. They even managed to put VOX and COMP on different menus! And there’a blank button beside VOX, where COMP should be! D’oh! Hey Icom, VOX and COMP should be on hardware buttons, and CW sidetone pitch should be in a menu! Then there’s the “Quick” button, which open a menu of things I’ve never used, and never will. Perhaps there should be 3-4 user-programmable hardware buttons, instead of 3-4 you’ll almost never use.
  • In SSB-DATA mode, RX bass and treble affect USB RX audio, giving your digi-mode software a non-flat response. Oops! Icom missed that line of firmware code. EQ is bypassed for SSB-DATA TX audio, but not RX.
  • The internal USB hub presents two virtual serial (COM) ports, but unlike the 7300, the RTS/DTR signals are ignored in the firmware, so you can’t use digi-mode software that asserts those RS-232 “pins” for PTT or CW keying. The first serial port provides CI-V rig control (on hex 88), and PTT is by CI-V command only. There is no CI-V command for CW keying, so the only way to run CW from a computer is to use an external interface. That’s a stupid omission, because the hardware is there, in the radio, they just didn’t use it. The second serial port provides a selection of RTTY or D-Star data (ASCII text output to a terminal emulator), or GPS NMEA interface (an external GPS may be used with D-Star, so the radio can look up nearby D-Star repeaters while mobile).
  • The USB interface also presents a virtual sound-card, and it works well, except that they used a chip with a known bug (there’s a TI white-paper on it): it’s a line-level device but it identifies to Windows as a microphone device, causing Windows to add +30dB to it. Adjusting the correct receive level for computer-based digital modes is somewhat tricky. Further, SSB-DATA audio I/O defaults to the 13-pin ACC-1 jack, so USB audio is dead until you enable it in Set → Connectors. See more details about soundcard set-up in the next article.

Low SSB Power?

Much has been written (and YouTubed) about the 7100’s SSB power. Indeed, out of the box you plug in the mic and talk and see about 13 watts on the meter. This is because it has a very fast ALC, pulling average talk power (and typical meters) way down. But the PEP is actually there! On mine, a little over 100 watts PEP, on a ’scope. There is no need to mod the radio, either with the capacitor mod, or the jumper mod. Version 5 of the firmware brings up average power some, though it still needs to be run with a fairly high ALC indication, and maybe a 1 on compression. If you are used to running SSB voice with little or no ALC indication, well, forget that, and run the 7100's ALC at about 40-80% indication. Also, like most Icoms, it has the initial ALC overshoot problem, so adding a capacitor to slow down the ALC is a bad idea, as it will certainly make overshoot worse, perhaps arcing your amp or tuner.

Other Setup Notes

Setting up the 7100 is pretty easy, but there’s a lot of features in there, and it’s a good idea to take time to go through both the Basic and Advanced manuals. D-Star is particularly confusing, and understanding the D-Star sections of the manual will require some background study on-line. If you have no interest in D-Star, you can get through the manuals pretty fast.

Programming repeaters, and other memory channels, is like earlier Icoms, in that you program everything into a VFO then write it to a memory channel. It’s not difficult, once you’ve done a few, but it’ a very tedious process. I bought RT Systems’ IC7100 Programmer software ($25) with the radio, and it’s darn well worth it. You just set up all your settings in a big dialog box, and memories in a spreadsheet, then send it all to the radio. Get the version without the CI-V programming cable, because it will send over the USB cable supplied with the radio.

The first thing to do is pop in an SD card and leave it. Any time you update memories or settings, back it up to the card. Press Set → SD Card → Save Setting → New File. Use the provided name, which is a date-time string. That way if anything gets messed up, you can always restore all settings and memories to a previous state. You can also pop the SD card into a PC and back up its contents—a good idea, since SD cards can fail. I keep my radio backed up to both the SD card and RT Systems software.

You can record QSOs (hundreds of hours on a 16-gig card), but unfortunately you can’t play them back on-air, without putting the card in a PC and moving them to a different folder on the card. Many people appreciate hearing a brief recording and playback of their transmitted audio, but it just isn’t properly implemented for immediate playback. Why can’t recording and playback be in the same folder? Another irrational oversight in firmware development.

There’s a little switch on the bottom of the control head for Ext. Speaker or Headphones. One would think it changes the output level, but no, it changes the jack from TS (2-conductor) mono to TRS (3-conductor), so you can run stereo headphones without need of an adapter. If you plug in your stereo headphones and only hear one side, switch the little switch.

About that Sloping Face

I keep hearing idiots (who don’t own one) calling it an alarm clock. I’ve never seen an alarm clock that looks like a 7100, but if there is one, it’s designer had some good sense in ergonomics design. Others say they can’t possibly mount it in a mobile, which is nonsense. Still others say you can’t mount the head on the radio, as if that’s somehow a problem. These are simply subjective reactions, because the radio looks different than most.

Radios are supposed to be a rectangular box with a flat vertical face, right? Why? Because long ago the knobs on the front of a radio used long shafts driving mechanical rotary switches and variable capacitors mounted on the main chassis deck, so a box was the only practical shape. But modern radios use optical encoders, and the only connection from the face to the radio is a ribbon cable or two. Yet still, traditions die hard (if ever), and most people still prefer a flat-faced box radio, even if they have to prop it up with a phone book to see it (the kick-stand is never quite enough). Having a perpendicular view of the face is even more important with modern LCD screens on radios. Placing a radio up on a shelf is problematic, because the larger radios, with rear cable clearance, require around 20 inches of depth; and a radio up on a shelf provides no arm support while dialing around.

The 7100’s 45-degree face is easily readable on the desk, or mounted on a RAM mount in the mobile. The RAM mount kit with a 2-inch flange on the bottom, a 4 or 6-inch extension tube, and a 2-inch flange with ¼-inch camera stud on top, is about $30 on Amazon and elsewhere. The flange can be screwed down to the top or side of the car’s center console, and the RAM mount adjusted to place the control head under the right hand. Not a problem! Or, if you’d rather place it on the top of the dash (a bad idea—too much visibility, too much sun), you can just get a little dash-cam mount. I recommend screwing it down—don’t depend on sticky-back or suction-cup mounts! They always fail. As for Icom’s optional mobile mount, well, I can’t see how it works; it isn’t very flexible; and of course, it costs way too much. Go with a RAM mount—they make high-quality mounting kits for mounting anything anywhere, and are good enough for police, military, and commercial marine applications.

If for some reason of portability and convenience, you want to mount the head on the radio, just get some 2-inch Velcro and stick it right on top! Coil up the excess cord, and you’re good to go. But you can’t mount it on the front of the radio, because the fan is front and center, and 1 or 2 cables exit the rear of the control head. I suppose one could use a 3-D printer to make a part that would replace the front plastic cover of the radio and contain the head, but it does seem rather pointless…

So in short, the detached, sloping head actually makes a lot of sense, both practically and ergonomically, even if it doesn’t follow tradition. Hopefully, more radios will migrate to split-component designs, just as desktop computers left behind the all-in-one designs 30 years ago, and hi-fi stereos 20 years before that.

Overall Impression

Given the form-factor, features, quality, and price, I’m very happy with it. Yes, if I were sitting up to a desk, I’d probably have a 7300. But for my operating needs, the little control head, mounted on a swing-out arm, and a boom mic, works very well. Now if it just had Bluetooth…

New Radio Day


Wow, what a long day! I knew the 7100 was out for delivery, but it didn't arrive until after dark!


I put the body up there on a shelf,


and mounted the control head on a swing-out arm by the bed.

What’s Next?

Next we’ll get into sound-card settings and calibration. If you’ve just acquired a 7100, it’ll save a bunch of time. And after that, panadapter on the Big Screen!

73, — KV5R

2 thoughts on “Icom IC-7100
  1. Thanks for the whole scoop!

    I look forward to re-equipping my old stuff. 17 and 30 meters aren’t the only thing, but they’re a good start. Great read.

  2. Very nice, thorough review of the IC-7100. I agree with most everything here. I have had one for several years and have no significant issue with the radio.

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