So far I have done the following.
-Switched tubes in same channel that redplated. The other tube then also redplated in that socket.
-Switched tubes from good channel to suspect channel and those started to runaway before I quickly turned off.
-I cleaned and retension both sockets in that channel. I also remade the connections to pins 5, 6 and eyelet 23 on the socket that redplated. The 1K resistors measure ok.
-With no tubes installed in that channel, both pins 4/5 measure approx -40vdc. The current does not run away without the tubes installed.
-At the rectifier diode I am getting approx -75vdc and then I get -44 approx at the 100uf caps in the bias supply.
- without tubes in channel, I measured higher voltage on can cap. half circle showing approx 466vdc and blank section 458vdc.
The current behaves without tubes installed in the suspect channel. Install the tubes (which both have redplated now in that same socket) and the current runs away and I have to turn it off before it approaches the fuse rating.
I am unclear what my next step should be, unfortunately I dont have another set of tubes and need a little guidance from here. Many thanks.
Last edited by rmk on Sun Jan 10, 2021 3:47 pm; edited 1 time in total