I built a grounded grid amp a few years ago....um..I guess 20..and used a pair of 4-1000PRs. I built it with RTTY contesting in mind. I used a separate filament transformer and B&W filament choke for
Another question(s) re 4-1000As. I see them pretty regularly at ham swap meets, used and cheap. Often with the carbon coated brown "tint" on the inside of the envelope. Does anyone know what the like
Pat, I agree that using a single tube makes more sense. You still may have a performance issue on 10M but if you are careful maybe not. The bottles I used were pulled from navigational aid sites but
The 4-1000A is rated far beyond 30 MHz. The problem is mostly in HF amplifiers that Plate current paths get to be long thus lowering the VHF parasitic frequencies so that choosing a suppressor that w
When I built my pair of 4-1000`s (GG/1972) I used very short plated strap for the plate leads and located the parasitic supressor at the cathodes ...Worked fine on 10 &15 meters,at slightly reduced e
The 4X1 was used in a huge number of 5KW AM BC transmitters; 2 in the RF deck and 2 as modulators. When the RF tubes got soft they were used in the modulators. By the time a ham got them they were fa