Help w/ Big Tube Coil

From: 	Jeff W. Parisse[SMTP:jparisse-at-ddlabs-dot-com]
Sent: 	Sunday, July 13, 1997 11:34 AM
To: 	'Tesla List'
Subject: 	Help w/ Big Tube Coil

At last month's TRW swap meet, I picked up two barely used 250W transmitting tubes. Last week, I purchased sockets, a filament transformer and a plate power supply and am now ready to start planning construction of my first tube coil. Brent Turner is going to help me put it all together (his book is a tremendous Tesla Coil resource that every beginner, intermediate or advanced coiler should have) but I'd also like to get the group's input.

The Specs:

Tubes:			CDR 250TH, PlateMax: 4kV, 350mA, Filament: 5Vac, 10.5A
Filament Transformer:	5Vac, 30A
Plate Power Supply:	2800Vdc, 680mA

The Questions:

1. Is a feedback coil the best (easiest?) way to pulse the grid of a CW TC?

2. What primary/secondary size and arrangement should be best for this power level?

3. Why do the secondaries of most tube coils appear to break the classic W:H rules (i.e. too tall & skinny).

4. Can/Should a toroid be used?

5. Any additional comments, suggestions?...

We're going to post start to finish construction details on our web site.

Jeff W. Parisse
Art Director, Digital Design Laboratories
www.ddlabs-dot-com  1-800-796-1138