3-1000 parasites

[k7yoo]

I picked up an old BTI 3-1000 amp recently and just like others I have seen/owned the band switch shows the telltale signs of parasitic arcing. I have info and a kit I purchased from Richard Measures about 10 years ago and will give the amp the full anti-parasite treatment along with the switch repair. Has anyone else had experience with these amps or the 3-1000? I mainly got the amp because I wanted to convert it to use a 4-1000A but thought I might as well try out the 3X tube for awhile.
Skip

[WD8BIL]

Hi Skip.......... good to finally meet ya.

Mom used castor oil for parasites.
Come to think of it, she used it just about anything 

[WA1GFZ]

I found an odd one while helping a friend get a linear going that is easy to deal with. The input fil choke has a resonance that would make the amp take off. We cured it with a 1 K resistor between the tube side of the choke and ac coupled to ground. This with the right network on the plate of the tube made it rock stable. A 4-1000A will drop right in but the gain will be slightly lower. The tetrode is slightly taller. gfz

[k7yoo]

That is good info about the filament choke. The slightly lower gain of the 4X1 might also be a + in this situation. The BTI manual mentions that you only need to saw 4 fins off the plate cap to use the taller 4X1. What they don't mention is the fact that the tuned input will need a few mods. The amp was built in the late 60's when exciters had tube finals and Pi networks that weren't fussy about 50 or 100 ohms, so I guess I can excuse the oversight.