none wrote:
(Snip)
couldn't find any.

At first, I suspected the cable between the TX and the front panel was
at fault, but moving it doesn't change anything. I will have to check with another
cable anyway.

I'd be thankful for any hints or advice.

Matthias HB9EGM


I am sure you will try the obvious to look with your eyes for broken or
pinched parts, tighten grounds, re-seat plugs and clean off any
oxidization.

From time to time I have had to troubleshoot equipment with partially
intermittent components or circuits. Freeze spray is sometimes
recommended, however I find freeze spray is not easily localized and
instead causes moisture to short out other sensitive circuits leading to
mis-diagnosis.

What you might first try, is to use artist's paint brushes of various
stiffness to probe the various components until the intermittent one is
found.

Secondly, if you do isolate an affected circuit schematically, but not
physically, you can use a trick I have used which is to use a small AC
coupled audio amplifier across the circuit to ground (biased either by
operating voltage or Ohmmeter) and listen for a micro-phonic affect as
you move the affected parts.

--
Joe Leikhim K4SAT
"The RFI-EMI-GUY"©

"Treason doth never prosper: what's the reason?
For if it prosper, none dare call it treason."

"Follow The Money" ;-P