[Icom] IC-765 Intermentent T- R in RCV

[K4WLS]

Hi Gang, Finally read rest of mail on this subject.

Not had IC-765 long, but have had few instances of intermittent
T-R switch on receive. Bumping paddle brings sensitivity back
up. Got this rig at estate sale, so do know how long it had been
"sitting up" (not being used).

Don't know about IC-765, but the QSK T-R relay contacts on my
Ten-Tec Corsair are gold plated, and I occasionally have the same prob
with it. Prob seems to come and last intermittenly for few days and
then goes away for months. 

Have ordered IC-765 service manual. Running a current through the
T-R relay contacts from a 13.8 VDC to a "sink" circuit on the other
side sounds like a risky process at best, even if you know what you
are doing. Some other causes for this problem besides oxidation
or dirt/dust on relay contacts could be:

Weak relay spring
Relay contacts not seating properly when coming back to receive

In the case of above, if you have the front of the rig fully elevated on
front feet, try sitting in flat on Op table and see if this improves things.

Also, try lifting the rig up from Op table, elevate to side and give it
a good shake. It's heavy so be careful !! This can loosen up a relay
spring that is somewhat bound and and possibly remove any foreign
matter in the relay mechanism or contacts. 

In the 6 Mos or so since I have had my IC-765 this has happened to
me 2 or 3 times. Bumping the paddle brings the receiver back up.

I will be interested in hearing more on this !!     73,  Larry  K4WLS