Golden Eagle 750 " relay help"

[Danzik]

Screen voltage was not found

 

[nomadradio]

and negative bias the finals had -111vdc of bias on pins 5 and 9 which seems high ?

Yeah, that's high. They used a NE-2 neon pilot lamp as a zener diode for the negative grid bias. If you can find a 82 Volt 5-Watt zener, it will probably take the place of the neon bulb okay. Just be sure to leave as much extra lead wire on the zener as you can. The surface of the lead wires is part of the heat sinking for that kind of component. Cutting the leads too short will raise its operating temperature for no good reason.

To replace the bias regulator bulb the banded end (cathode) of the zener will go to ground.

Whups, was replying to the previous post. Screen voltage is necessary too. Seems to me the schemo is in a publication I uploaded called "Amplifier World". Should be posted on the forum here...

73

 

[nomadradio]

Hmm. Turns out what's at the very end of Amplifier World is the 1k model, not the 750.

https://www.worldwidedx.com/threads/amplifier-world-im-the-dog-who-caught-the-car.267821/

Gotta see if I have the 750 on file.

Found it. See attached file.

Makes it appear the final tubes have the screen grids grounded. Only the two driver tubes have positive voltage on the screen grids.

73

 

[Danzik]

Hmm. Turns out what's at the very end of Amplifier World is the 1k model, not the 750.

https://www.worldwidedx.com/threads/amplifier-world-im-the-dog-who-caught-the-car.267821/

Gotta see if I have the 750 on file.

Found it. See attached file.

Makes it appear the final tubes have the screen grids grounded. Only the two driver tubes have positive voltage on the screen grids.

73

Thank you very much Nomad ! I found the issue and it is now working again and it did have to do with the screen voltage, it appears possibly it was old corrosive Flux in behind the HV board around the wire that carries the screen voltage and the round transistor there . Thanks a ton

 

[nomadradio]

Rock on! Congratulations for sticking with it!

73

 

[Danzik]

Rock on! Congratulations for sticking with it!

73

Thanks man