[1000mp] MP Relay/Receive Problem

[Rod Elliott]

John et al...

I have a December 1996 MP. About two years ago I began to notice occasional 
RX desensitization that varied randomly from slight to totally dead. This 
was not band-specific and happened with the ATU on or off. It was easy to 
cure by sending a dit. However, as time progressed it became more frequent, 
severe, and difficult to clear. Eventually it got so bad that ANT A was 
(and still is) useless. So, I switched over to ANT B, and have had no 
problems since. Never checked to see if AGC on/off had any effect.

To me, this sounds like a dirty relay contact. I believe a  semiconductor 
would be either functional or dead, and thus wouldn't show a progressive 
deterioration.

By the way, I had identical symptoms with my old FT-102, starting when it 
was about 3 years old. I took the big hammer approach on it: Pried the 
plastic covers off all the RX-circuit relays I could find, and cleaned each 
contact with contact cleaner and lint-free paper. Put the covers back on 
and sealed them with magic transparent tape. After that had no problems in 
the next 10 years of operating. Somebody once told me there was lubricant 
on the contacts which was gumming up... once removed, no problem. Sounds 
possible, particularly in low-level circuits.

73
Rod Elliott VE3IRF



At 08:55 05/27/02 -0400, you wrote:
>I've got the same problem in my MP, late '95 vintage. I've never tried
>turning AGC off to see the effect. A single quick transition to TX
>always bring it back to full life RX. It has never come back to life on
>its own without my intervention, but then I've not sat around waiting
>for it to do so. On my rig it appears somewhat infrequently, as reported
>by others, and cannot be duplicated at will.
>
>I'm eagerly awaiting ideas as well.
>
>73, John W2KI
>------
>
>Barry N1EU wrote:
> >
> >
> > I suspect this problem has been happening to many MP owners out there and
> > they aren't aware.  By bringing it to the attention of the reflector, I
> > think we'll see a lot more reports of it in the future by serious 
> contesters
> > who spend a lot of time running (cq'ing) with the MP.
> >
> > It sure would be great if Yaesu would solve this one, but I'm not 
> holding my
> > breath.  As SM0KCO suggests, it very well might be a semiconductor problem,
> > not a relay problem.
> >
> > 73,
> > Barry N1EU
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