Finished the 3C24 VTTC and now it dosn't work!
Vaxian, Wed Apr 18 2007, 05:38AMHad first light with the coil strewn across the desk and wired together with jumpers.
Put it all nice and neat into the lexan box I made for it and NOTHING!
The tube get's REALLY hot with just 40-50 Volts, no oscillation.
Have checked over the wiring numerous times, seems all OK.
Have tightened, taken apart, retightened all connections.
Any suggestions on what may cause this? I'm at my wits end.
Re: Finished the 3C24 VTTC and now it dosn't work!
..., Wed Apr 18 2007, 06:45AM
You double triple checked the phasing?
Also, I am a little worried about how close your secondary is to the mot, in my vttc I had to have about 1/2" of empty space and an aluminum plate between them or it would have trouble oscillating.
..., Wed Apr 18 2007, 06:45AM
You double triple checked the phasing?
Also, I am a little worried about how close your secondary is to the mot, in my vttc I had to have about 1/2" of empty space and an aluminum plate between them or it would have trouble oscillating.
Re: Finished the 3C24 VTTC and now it dosn't work!
Coronafix, Wed Apr 18 2007, 06:59AM
I was also going to question the MOT proximity.
Terry Fritz did some analysing of this and found that
having the coil central over the MOT helped a lot,
but it may still need raising.
Coronafix, Wed Apr 18 2007, 06:59AM
I was also going to question the MOT proximity.
Terry Fritz did some analysing of this and found that
having the coil central over the MOT helped a lot,
but it may still need raising.
Re: Finished the 3C24 VTTC and now it dosn't work!
Vaxian, Wed Apr 18 2007, 11:22AM
Hmmmm,
It was like that nwhen it was working before. The plate cap and grid leak were jumpered in.
I will try tilting the top away from the MOT and firing it up though.
Thanks
Vaxian, Wed Apr 18 2007, 11:22AM
Hmmmm,
It was like that nwhen it was working before. The plate cap and grid leak were jumpered in.
I will try tilting the top away from the MOT and firing it up though.
Thanks
Re: Finished the 3C24 VTTC and now it dosn't work!
Steve Conner, Wed Apr 18 2007, 01:05PM
Sounds like your feedback was only just enough to start with, and the new tube has less gain than the old one. Try more turns on the feedback winding, and/or a bypass cap across the grid leak resistor if you don't have one already.
Steve Conner, Wed Apr 18 2007, 01:05PM
Sounds like your feedback was only just enough to start with, and the new tube has less gain than the old one. Try more turns on the feedback winding, and/or a bypass cap across the grid leak resistor if you don't have one already.
Re: Finished the 3C24 VTTC and now it dosn't work!
Vaxian, Thu Apr 19 2007, 03:18AM
IT LIVES!!! wha ha ha ha!!!
Dosn't make any sense, I rewired the grid leak in phase the same way it was for first light (EXACTLY)
I turned it around and it oscilates!
Still getting hot really fast but I'm getting sparks!
Will share spark pix when they are above 1/8" with a red plate.
Thanks everybody.
Think I'll wind a better primary with more taps and a larger grid leak resistor may help.
Vaxian, Thu Apr 19 2007, 03:18AM
IT LIVES!!! wha ha ha ha!!!
Dosn't make any sense, I rewired the grid leak in phase the same way it was for first light (EXACTLY)
I turned it around and it oscilates!
Still getting hot really fast but I'm getting sparks!
Will share spark pix when they are above 1/8" with a red plate.
Thanks everybody.
Think I'll wind a better primary with more taps and a larger grid leak resistor may help.
Print this page