View Single Post
Old 16th Sep 2019, 11:32 am   #43
peter_scott
Dekatron
 
peter_scott's Avatar
 
Join Date: May 2003
Location: Edinburgh, UK.
Posts: 3,273
Default Re: Yet Another Bush TV22

I would like to do something similar to that Hugo but I confess that currently I just have my modern electrolytics just hanging on their wires.

The frame timebase does appear to have quite a few high impedance nodes so I suppose I shouldn't be surprised that 50 Hz mains can get in where it's not wanted. Just touching my 1M scope probe on any of the oscillator transformer connections gives a substantial increase in scan amplitude.

With the hum bucking C60 in place the HT ripple is 1 volts p-p. With it disconnected the ripple is 3 volts p-p but with or without C60 the apparent amplitude of the frame ripple doesn't appear to change!

Peter

Last edited by peter_scott; 16th Sep 2019 at 11:49 am.
peter_scott is offline