Icom IC 251 - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

nemo1956 · 26th Mar 2021, 10:51 pm

Hi all. Well here is an update on the 251 PSU problems.
I gave up on it.
I replaced the hole thing with a new SM, PSU for a laptop. It's running well now.
I did find that the opto coupler was OS on both sides so at that point I decided to call it a day.
Thanks for all your help on this problem.
Now the next problem with it is the microphone is nor working so I bought a replacement but found the audio to be very low.
On investigating this I find the so called direct replacement microphone has no per-amp inside it.
Cheap Japanese crap has struck again.
So I'm. Putting a single transistor inside so that should fix the lack of signal at the input.
73's.
Paul.

26th Mar 2021, 10:51 pm	#21
nemo1956 Triode Join Date: May 2016 Location: Phimai, Thailand. Posts: 49	Re: Icom IC 251 Hi all. Well here is an update on the 251 PSU problems. I gave up on it. I replaced the hole thing with a new SM, PSU for a laptop. It's running well now. I did find that the opto coupler was OS on both sides so at that point I decided to call it a day. Thanks for all your help on this problem. Now the next problem with it is the microphone is nor working so I bought a replacement but found the audio to be very low. On investigating this I find the so called direct replacement microphone has no per-amp inside it. Cheap Japanese crap has struck again. So I'm. Putting a single transistor inside so that should fix the lack of signal at the input. 73's. Paul.