----- Original Message -----
Sent: Monday, November 28, 2005 1:21
PM
Subject: [drakelist] R4C repair tip
Hallo, just few words on a new ( for me
) problem on an R4C
PTO not working. Checked the + 11V
supply, not present.
Changed C165, tantalum cap. The supply
goes OK, but the pto, now oscillating, is warbling up and down in frequency on
a random basis.
Dismounted and changed the 8 V zener
diode. Absolutely perfect!
At school, 30 years ago, I learned
about the fact that zener diodes are noisy devices, but this has been the very
first time I experienced this .
I hope that this tip will be useful to
the reders!
Regards
Carlo Bianconi
IK4ISQ
