Dual GI46A HF Linear Power Amplifier

I always wanted to build a high power linear for HF bands. Some time ago I had purchased a Gunset 200 (4X811) linear. I played with it and eventually upgraded to (4X572) tubes. That didn’t go well so I ended up scraping the project and only saved the HV transformer. Later on, I acquired a Heathkit SB200 main chassis. Utilizing the saved HV Transformer I built a linear with two Russian tubes GI46A. I used the original SB220 PI filter with some modifications to add 6m operation. At the end I was able to achieve 950W RF on 80, 40, 20 and 15m bands but only 700 W on 6m. I believe the HV transformer was limiting me to get more than a KW. That was the reason I ended up modifying the Harris TV channel 2 modules for 6m as the next project below which gives 1KW all day long.

Preliminary state of the equipment

Linear amplifier completed

Close view of the PA

Circuit Diagram

Here is an interesting publication for Power Amplifiers builders with high power vacuum triodes

Triode Board