[ICOM] Icom 765 - loss of audio & transmit !

[Will]

I own a fairly late model ICOM 765. About 2 years ago I replaced the 
VCO trimmers; these were bought direct from Icom UK as I was 
experiencing many of the symptoms related to the need to replace 
them. Raspy SSB audio etc etc.   I was, at the time, not convinced 
that the replacement trimmers were of the ceramic type but, after a 
call to their head office in Kent, England, I was assured that they 
would do the trick. The replacement procedure went without a hitch 
and all has been well since.  The past few days I have had the 
following experiences. When I switch the rig on, I more or less 
immediately lose any audio and am unable to transmit on 7 Mhz or 
below. Switching bands up to 10, 14, 21 Mhz etc both transmit and 
receive is fine but when I go back to 7, 3.5 or 1.8 Mhz, I cannot 
hear a thing nor am I able to transmit.  I switch the rig off and 
leave it for a while and, on a intermittent basis, when I switch it 
on again, I can transmit and receive on 7 Mhz or below. The audio 
then fails as does the ability to transmit. There is definately an 
intermittent fault, be it a dry joint or a dodgy bit of switching on 
the bands mentioned. I think I may have a faulty VCO trimmer but has 
anyone else experienced this. In particular, the fact that it is only 
affecting 7 Mhz and below ???  kind regards Will / GM0HKS

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