Re: First VTTC light, and a few questions

["David Trimmell" <davidt-at-pond-dot-net> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

Hi, This post by Ralph leads me to ask: you are grounding the filaments?
The reason a CT Filament Transformer is nice, but you can still ground one
side (I do, often). Any C (500 or so PicoF) to ground will take care of
nasty RF.

David Trimmell

At 07:37 PM 7/20/00 , you wrote:
>Original poster: Parpp807-at-aol-dot-com 
>
>Grayson,
>As the circuit starts to oscillate, as the plate current increases, all sorts 
>of dirty RF
>flows into the filament circuit. I played with a pair of #10s and a pair of 
>45s. Both tubes are directly heated and exhibited the behavior you describe. 
>I have very little experience with
>VTTCs. Bypassing the filaments to ground eliminated the problem. I used a TV 
>transformer with a fil CT but that should not make any difference. I have 
>some big
>plate transformers that I hope to use with 4-811s or 4-836 triodes. The 836 
>has a large graphite plate and should make things nice and toasty. Sorry I 
>can't be of greater help
>but my experience is :-((.
>
>Happy day,
>Ralph Zekelman
>
>
>