View Single Post
  #4   Report Post  
Old July 28th 03, 05:54 AM
Craig \(WB6LZV\)
 
Posts: n/a
Default

Great news on cleaning the switch. What you found sounds about right.
Alignment should help with the frequency adjustment problem. I've also had
to replace transistors in the buffer stages between VCO circuits after I've
fixed the switch. For some reason, they failed... most likely from the
switch failure. This was the case in two of the 6800W's that I repaired.
The good news is that you can get replacement substitution transistors.

Regards,
Craig

"Jean Bernard Pinelli" wrote in message
...
Craig!

Ok & tks for advise.

I spend some hours today in order to remove S6... (main board removal is a
nightmare!) Inside S6 was a kind of green jelly and corrosion on the

silver
contacts. After cleaning (ultrasound + polishing) I put into S6 a silicon
paste normally used in high tension transformers (radiology) in order to
avoid corrosion on the bushes. I have also removed and cleaned 2 others
switches (S1 & S2)

After re-assembling the set, a great improvement: readout on digital meter
is now in accordance with position of SW band selector. I have now to
adjust VCO1 & VCO2 (and probably whole set adjustment) as frequency dont
change yet when I turn tuning dial knob....

I keep you informed! Again thank you!

Jean

"jb.pinelli" a écrit dans le message de news:
...
Hi you all,

I need an advice, as I try to repair my (old) Sony ICF-6800W...(Sony, of
course, refuse to do the job)

a) AM & FM are ok
b) No sound on SW bands... Digital led readout indicate wrong values.

Drum
&
preselector are ok.

If someone got the same problem... any advise welcome!

Jean