12-04-2011, 06:06 PM
Hello everyone!
New to the forum and need some help.
Looking to bring back to life a 41-250 (X-Mas gift for the father in law).
Here's what I found:
Dead 84 rect.
Questionable Osc and 1st det tubes (both XXL)
questionable because my Hickok manual had an error in it
So I ended up checking them wrongly and I think they were hurt in the process
Don't use the consolidated Hickok manual settings for an XXL tube use the settings for a 7A4...Story for a different post
What I have done so far:
Replaced all paper caps
Replaced the 250uf items21&21A and the 370uf items24&25
new 84
two new XXL (7A4)
replaced a hand full of the rubber wires that were cracked bad.
cleaned all the contacts with deoxit
Temporarily bypassed the arching on/off switch until I can get the replacement installed
After power up I have nothing but occasional subtle static and a real slight hum
voltage across item 27A (16uf) is spot on 182V
voltage across item 62 (12uf) is spot on at 266V
voltage across item 27 (8uf) is way high at 183V
Reading at the plate of the osc is the same 183V
The 33Kohm and the 18kohm resistors at location 26 & 28 respectively check ok.
what is driving the high voltage?
HELP
Thanks
Joe
New to the forum and need some help.
Looking to bring back to life a 41-250 (X-Mas gift for the father in law).
Here's what I found:
Dead 84 rect.
Questionable Osc and 1st det tubes (both XXL)
questionable because my Hickok manual had an error in it
So I ended up checking them wrongly and I think they were hurt in the process
Don't use the consolidated Hickok manual settings for an XXL tube use the settings for a 7A4...Story for a different post
What I have done so far:
Replaced all paper caps
Replaced the 250uf items21&21A and the 370uf items24&25
new 84
two new XXL (7A4)
replaced a hand full of the rubber wires that were cracked bad.
cleaned all the contacts with deoxit
Temporarily bypassed the arching on/off switch until I can get the replacement installed
After power up I have nothing but occasional subtle static and a real slight hum
voltage across item 27A (16uf) is spot on 182V
voltage across item 62 (12uf) is spot on at 266V
voltage across item 27 (8uf) is way high at 183V
Reading at the plate of the osc is the same 183V
The 33Kohm and the 18kohm resistors at location 26 & 28 respectively check ok.
what is driving the high voltage?
HELP
Thanks
Joe