[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

New VTTC (fwd)



---------- Forwarded message ----------
Date: Fri, 3 Aug 2007 23:04:31 -0700
From: James Zimmerschied <zimtesla@xxxxxxx>
To: Tesla <Tesla@xxxxxxxxxx>
Subject: New VTTC

Hello to list members, Lately I have been spending time and money putting
together my first vacuum tube coil. I wanted to do this type of project
for a long time but it took incentive such a Cameron Prince's and Chris
Hooper's results that made me go ahead with the project.

I used the design on Steve Ward's website pretty much as a cookbook design
(thanks Steve) with some added help from Brett Miller and John Freau. I am
using the 833C Taylor tube from RF Parts. Many of the other items I had in
my spare parts so that helped some on cost.

I made use of a bunch of Sangamo mica caps in a MMC arrangement for the
tank capacitor. I have a staccato board but haven't go that working yet.
My current best spark length is around 18". This is below the performance
that others have achieved but I am confident that there is room to
improve. I will be adding a lexan shield at the top of the primary form as
others have done. I took a heavy secondary to grid coil arc pushing the
grid coil location upward. The arcs from this coil burn through PVC
voraciously in the few seconds of breakdown that occurred.

A few specifications:
secondary is 900 turns of #28 on a 4 inch PVC form.
primary is 32 turns of #12 stranded on a 6.5" PVC form
tank cap is 0.002uF
grid leak resistor is 5K Ohms (100W)
grid leak cap is 0.002uF ceramic disks
one MOT with DC doubling
three micorwave oven caps (~4uF)
grid coil is 25 turns of #20

I was happy to be able to get this going without too much problem. Thanks
to the VTTC pioneers and those who willingly share their knowledge.

I tried to send some photos but they were apparently blocked. If the
moderator could let me know the current procedure, I could get some photos
posted. Jim Zimmerschied