Hygain Afterburner Plus 482 Grid Bias

[kopcicle]

I'd have to desolder at least one end to check it,correct?

in this case, no. Capacitor on one end and space on the other at rest.

 

[743SEPA]

Do these tube units have any residual voltage I need to worry about,don't want to get lit up.

 

[BlowinSmoke]

Do these tube units have any residual voltage I need to worry about,don't want to get lit up.

It's not the tubes you need to worry about, it is the filter caps that may have open or no bleeders.

 

[kopcicle]

More on this in it's own thread

 

[Shadetree Mechanic]

View attachment 39037
More on this in it's own thread

Wow, that's some transformer there. I think you need more tubes. Haha.

 

[Dmans]

Reminds me I need to drag my Hy-Gain out and power it up for it's Bi-Annual run!

73
David

 

[kopcicle]

What is new is old
http://www.813am.qsl.br/artigos/moduladores/hileman/Class_K_Modulator_CQ_Oct_53.pdf

Wayback Machine

 

[nomadradio]

Wow, that's a trick I don't remember stumbling across.

73

 

[Shockwave]

Since the tubes are wired as grounded grid triodes, is there any reason we are not biasing them as such, through the cathode? It seems like lifting RFC 1 from ground and inserting a zener or a string of silicone diodes bypassed with a cap, would be the way to go here. You can precisely dial in the bias current, without worrying about other available supply voltages. Add a DC blocking cap to prevent that bias from going back into the radio.