Here are some various tubes I've used for VTTC projects. I also showa completed small 4-125A tesla coil project, with various notes.
https://sites.google.com/site/jfuturet/home
I also have some small 4" diameter toroids listed on ebay:
https://www.ebay.com/itm/4-x-1-Spun-Aluminum-Toroid-for-Tesla-Coil-High-Voltage-Marx-Generator-Polished/223285898946?hash=item33fce06ec2:g:Y~8AAOxyuuJR3veX:rk:2:pf:0
Also a couple of solid state power supplies that might work well to power a VTTCinstead of using an MOT. I've always meant to try this, but I'll probably neverget around to it, so I listed them on eBay.
https://www.ebay.com/itm/2-Panasonic-Inverter-High-Voltage-Power-Supplies-4000-VDC-Tesla-VTTC-Project/323623685393?hash=item4b59798d11:g:jbsAAOSwKStbkB0J:rk:6:pf:0
Tubes with graphite plates such as the 810 can handle more than their ratedvoltage and power. The HF-300 or HF-200 work well, for a VTTC. Tubessuch as the 4-400A, 4-1000A, work well too. I just tie the two grids together.I particularly like using the 833A or 833C (graphite). There are a bunchof rarer tubes than can work well that look like an 810 and have graphiteplates. Such tubes might sell cheaper since they are not popular. Someexamples are: EV-20, KU-23 (same as HF-300), HF-100 (a little smaller).
The 813 tubes tend to sell very cheaply and they work well also (graphite),they are tetrodes.
I don't like the 811 or 812 tubes much because they are rather feeble in theiroutput power. However the 572B is stronger but can only withstandlimited voltage. Yes, the 304TL (or TH) are interesting tubes. I've alsoused the 3-500Z.
John
-----Original Message-----
From: derstrom8--- via Tesla <tesla@xxxxxxxxxx>
To: tesla <tesla@xxxxxxxxxx>
Sent: Thu, Dec 27, 2018 10:44 am
Subject: Re: [TCML] First VTTC - Some help needed choosing tubes
Hi Chris,
I have been on the fence regarding a staccato controller, though I most definitely have the means and ability to make one. I think I'll probably go that route, and thus will probably use the doubler (depending on the capabilities of the tube I end up using, of course).
I am also flexible on the secondary size, I just mentioned 4.5" x 16-18" because I already have PVC this size on-hand. I'm pretty sure I've seen coils this size run from 811 tubes before. That being said I'm still looking at other tubes, most recently the GU-81M pentode. This tube seems rather beefy but is still pretty cheap and would fit my budget. Here's the listing: https://www.ebay.com/itm/GU-81M-81M-generator-pentode-tube-Tesla-Coil-750W-50MHZ-Military-USSR/113446069628 . It's used but looks to be in excellent condition. Seller has 100% positive feedback, granted there are only 92 ratings. Still seems fairly trustworthy though and I think might be worth the bet. I'd just need to know what to do with the extra electrodes. I've seen them used for current limiting and other things, but I think for my first VTTC keeping it simple is the best option.
I have read through Steve Ward's VTTC pages a number of times. There's lots of great information there, and I find myself continually going back and re-reading it to see if I can glean more from it.
Rest well,
Matt Lewis, Fairlee VT
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