I am new to the Group, a friend of mine suggested to ask my problem here as there are many capable Hams on this group.
I have a GS35 on 2m and has been working for years, I have changed the tube during it's life and blown a bias transistor here and there.
The problem I am having now is one I have never seen. When I apply HT to the Amp usually the Amp is cut-off with the cut-off resistor and no current flows. Now I get Negative Grid current and Anode current starts to flow, and the more I increase the Anode say from 1000v to 1500v the current increases.
The things I have changed in the Amp:
Tube - New tested good tube installed.
Bias Board - tested adjustable from 0 to 55 v
Filament Transformer
HT & Heater feed-thru cap.
Usually when the Grid Bias transistor goes - I am using a BDX66B from DL4MEA design (? ) the amp does not do anything so not sure that Bias is the problem.
I anyone might have come across this negative grid current problem please let me know.
