R7100 clicking sound

[K3JTP]

I recently picked up an IC-R7100 that works fine except for an irritating random clicking inside, which I'm assuming may be the relay. I am monitoring air bands below 380 MHz, so the relay should not be closing, and the reception is not affected by the clicking. I have had several R7100s before, but I have never experienced this issue. Is it the relay that is causing the clicking and is there any way to fix it?
Les Polt
Baltimore

 

[K3JTP]

In reply to my own posting I came across a similar thread years ago, which duplicates my issue:The relay opens as soon as the squelch is broken and closes about 2 seconds after the squelch closes. Is there a way to lubricate the relay or minimize the noise? I have not experienced this with other R7100s.
Les Polt

 

[iMONITOR]

Years ago I was told it was caused by band switching circuits, but that was when it was heard during scanning different bands/frequencies. However I found this info below. I can not confirm.


Icom IC-R7100 and its clicking noise
https://ea4eoz.blogspot.com/2017/11/icom-ic-r7100-and-its-clicking-noise.html

 

[K3JTP]

Thanks. That seems to be the answer, if I can access the Main Unit.

 

[RFI-EMI-GUY]

Years ago I was told it was caused by band switching circuits, but that was when it was heard during scanning different bands/frequencies. However I found this info below. I can not confirm.


Icom IC-R7100 and its clicking noise
https://ea4eoz.blogspot.com/2017/11/icom-ic-r7100-and-its-clicking-noise.html

It appears it would be very easy to remove the relay, replace it with an optoisolator and dropping resistor for the LED. This could be soldered on a square of perf board and fit exactly in place of the relay. The you would still have that functionality.

I used the record function to activate PTT of a small low power UHF transmitter so I could monitor remotely.

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[Ubbe]

Doesn't the optoisolator need to be able to handle both high UHF frequencies and low uV levels?
I've never seen a semiconductor solution for any of those receivers that use relays to shift frequency bands.

Maybe it could be possible to source relays that are not so loud and put on a seperate board that doesn't lead the clicking sound to the chassi and perhaps wrap sound dampening material around it?

/Ubbe

 

[RFI-EMI-GUY]

Doesn't the optoisolator need to be able to handle both high UHF frequencies and low uV levels?
I've never seen a semiconductor solution for any of those receivers that use relays to shift frequency bands.

Maybe it could be possible to source relays that are not so loud and put on a seperate board that doesn't lead the clicking sound to the chassi and perhaps wrap sound dampening material around it?

/Ubbe

The relay is switching DC like the remote start stop switch of an old cassette recorder. For whatever reason ICOM had no provision to disable the relay in that model and it clicks away. They could have used an optoisolator when the designed it but, maybe a relay was cheaper.

Some ICOM receivers do have bandswitch relays, my R9000 has one and I have to keep frequencies in the banks in the same range or it makes a click. Annoying.

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