Icom R7100 VHF/UHF Rcvr.

spongella

SatelliteGuys Pro
Original poster
May 12, 2012
1,625
1,236
Central NJ
Wonder if anyone has or had the Icom R7100 25 MHz - 2 Ghz receiver, and how did they like it? Seems to have good ratings on eham.net. It's an older receiver that users claim has excellent sensitivity. Thanks.
 
I've had one since they first came out. It was a very good receiver back then but most of them now would be old, detuned, degraded and subject to failure at any moment.


Wonder if anyone has or had the Icom R7100 25 MHz - 2 Ghz receiver, and how did they like it? Seems to have good ratings on eham.net. It's an older receiver that users claim has excellent sensitivity. Thanks.
 
  • Like
Reactions: spongella
I had one of these for a few years and traded up to an IC-R8500. It was a nice receiver for its time.
Like the 8500, Icom has deemed it obsolete and won't service them anymore.
I found a guy in Georgia who will service them (through Icom). He is a former factory tech and sounded fluid in his knowledge.
Parts are almost unobtanium. Common loss of VHF sensitivity leads to the RF amp section and good luck finding the specialized transistors that are sensitive to "taking a shot". Sucks because they are such nice radios.
PC interface software support makes them more flexible.
I like the "hands on" of dial spinning late at night and always have.
Fortunately/unfortunately SDR radio has now become the mainstay of amateur radio technology these days.
SDR is pretty great if you don't have nostalgia burned in your brain. Still finding myself firing up the Collins boat anchor and enjoying the warm glow and smell of tubes.
Dollar for dollar taking a chance on a radio that "works perfectly" that is X years old versus a comparably priced SDR that is new, the SDR definitely would be the wiser choice. I've tweaked in the RF section of my 8500. It's still pretty"hot". SDR does better though since things like filters, modes, scan and store, etc. are right at your finger tips.
Hope this helps.
 
As for it being old and possibly de-tuned I agree. After looking through the service manual though I will do the realignment myself. I like older receivers like the R-7100, it weighs 14 lbs and has a real D'Arsonval S meter, not a cartoon S meter hi hi.

SDR is great, been through that phase, I like the fact of having a spectral view and waterfall, something the R7100 does not have, but as you say spinning a dial has intrinsic value. Thanks for the comments.
 
  • Like
Reactions: KE4EST and raydio
spongella
Mario, when you get it show some pics. Inside pics too while you have the case off. Would love to see a small video of it as well.
 
  • Like
Reactions: spongella
Mike, wish I had read your post sooner. Spent a few hours yesterday morning just changing the two 2032 memory batteries. One is for the clock, other for the 900 memories. The manual was not complete in their description of how to replace 'em; it was much more complicated. I'd say this was the hardest battery change to deal with so far, but at least Icom didn't solder them in place. It was a good learning experience though.

When buying older equipment always keep in mind that memory batteries get old and may need replacement. Some radios like the Yaesu FRG-100 make it a snap while other radios like some 2 meter xcvrs require soldering and lots of complicated surgery to get to. When I start alignment will take photos Mike. Thanks.
 
I agree on some make it very complicated. Almost as if they figure the radio with be trashed by the time the battery goes dead. I have a replaced the battery in quite a few 2 meter/440 mobiles, that did take some extensive surgery!
 
  • Like
Reactions: spongella
Wow. Batteries. Who would have thought!
At least the receiver doesn't "time bomb" and forget who it is when one goes dead or because you didn't piggy-back in a new one.
Has anyone out there run into one that does?
 
  • Like
Reactions: spongella
Has anyone out there run into one that does?
No, they still work, but you can not program any memories in. If you do, turn off the radio and back on and they are gone. Also, it is very annoying to turn a radio on and it forgets where the VFO was last at, including any settings, one had programmed. Such as CTCSS tones, digital mic gains, RF squelch, etc.
 
  • Like
Reactions: spongella
No, they still work, but you can not program any memories in. If you do, turn off the radio and back on and they are gone. Also, it is very annoying to turn a radio on and it forgets where the VFO was last at, including any settings, one had programmed. Such as CTCSS tones, digital mic gains, RF squelch, etc.
Is this when the batteries are dead or even after new ones are installed?
Makes me want to dig into the schematic of my 8500.
 
  • Like
Reactions: spongella
Just when the battery dies. After you install a new one that work fine. They have BBRAM in them. "Battery Backed-Up RAM" Lasts longer and faster than EEPROMs. EEPROMs only have so many write cycles. Also, just think about when you are spinning your VFO on an HF rig. Every time the frequency changes, the change is instantly stored. Not only would it slow down your tuning it would kill an EEPROM in no time. Much faster for a micro-controller to write to regular RAM then EEPROM. :)
 
  • Like
Reactions: arlo and spongella
Used to have one back in the 92 and installed a kit purchased then from the UK for about $20.00 that opened 0-25Mhz
Had it installed by a radio shop in Burbank for $25.00 (had to many cables to be soldered into fragile chips and didn't want to take any chances)
Scanned perfectly from 0-2000MHz with no issues whatsoever after KIT was installed.

Wished I never sold it in 94.
 
A follow-up photo of the R-7100A once the upper and lower chassis are separated. The two coin cell memory batteries are on lower right.
 

Attachments

  • IMG_0964.JPG
    IMG_0964.JPG
    83.4 KB · Views: 253

Users Who Are Viewing This Thread (Total: 0, Members: 0, Guests: 0)

Who Read This Thread (Total Members: 1)