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Registered Member #1643
Joined: Mon Aug 18 2008, 06:10PM
Location:
Posts: 1039
Are all doorknob caps suitable? The only ones I find with RF capacitor in the tag are these
Which well, they come in 3300, 2200, and 1000pF but that cost is a bit up there. 3 series would give 30KV 1.1nF but, 80 bucks is a bit to spend on such if im not mistaken...
Registered Member #4108
Joined: Sun Sept 25 2011, 11:43PM
Location:
Posts: 149
my vttc uses a stack of capacitors to get 120kvar, the sparks is my profile picture you want huge kvar rating on the primary, if it is it will be more efficent!
Registered Member #1643
Joined: Mon Aug 18 2008, 06:10PM
Location:
Posts: 1039
Well, for cost factor, i dont see anything wrong with getting a single 1nF, 12KV, 90Kvar capacitor then...i mean, it sounds like its correct to me...decent Kvar, voltage is up there, 1nF as it seems it should be by a guess...just need to make a better primary/tuning coil.
Registered Member #3806
Joined: Sat Apr 02 2011, 09:20PM
Location: France
Posts: 259
I got real improvments on my 572B VTTC when I replaced my poor dorknow tank cap by a K15Y-1 one !
The benefits were: - Improved output with lower input current - This cap doesn't heats at all, so fres stays stable - No more tube plate reddening
These K15Y-1 caps are great, I bought them from this guy, I received my order quickly and caps were very well packed. But he is on holiday until August the 17th.
Registered Member #152
Joined: Sun Feb 12 2006, 03:36PM
Location: Czech Rep.
Posts: 3384
The Q of the primary of a VTTC is usually around 10, so a 90 kVAr cap is probably good up to some 9kW of input power. For your application overkill, but no way you can damage it, these caps will take anything you throw at them.
Registered Member #1643
Joined: Mon Aug 18 2008, 06:10PM
Location:
Posts: 1039
Just thought id update with today's mail. I wont be able to get the thing done in awhile, as im a bit busy on other projects (DIY CNC computer / 1Tesla DRSSTC) as well as working a lot...job. But, i'll put things together someday, in triode style, and see where this capacitor takes me. Do have a primary of i think 48 turns, with taps every 6 inches - Lots of taps, and running off that 1mhz blue coil. So. Hopefully when i next get around to it, I'll be able to get better performance :)
Capacitor is a lot heavier than i thought it would be... 1nF 12KV 90KVAr
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Need tips for a VTTC.
you want huge kvar rating on the primary, if it is it will be more efficent!
