On Thu, 04 Dec 2008 06:23:48 -0800, JIMMIE wrote:

After years of avoiding morse code I am finally getting into it. the
ideal of operating a very simple transmitter appeals to my junkbox/
trashcan construction mentality.
I am looking for a substitue for a 6L6 that has the plate brought out
the top. I was trying to build a little Glowbug transmitter but was
having all kinds of problems neutralizing the the thing. I think I would
have better luck if I can separate the grid and plate circuits from each
other. I am considering an 807 as a replacement Suggestions would be
appreciated.

Jimmie

Have you considered a 6L6 with careful shielding at the socket? IIRC the
pins that neighbor the plate pin would be at RF potential; you could put
a big, flat, high-value ceramic right between those socket pins to shield
the grid, and possible even extend the shield out if you were willing to
hand-make a cap from copper strip and Kapton tape.

It's kinda heroic measures to take on a tube that's more expensive now
than it's "high-tech" RF brethren, but if you just gotta have that metal-
tube look it may do the trick.

--
Tim Wescott
Control systems and communications consulting
http://www.wescottdesign.com

Need to learn how to apply control theory in your embedded system?
"Applied Control Theory for Embedded Systems" by Tim Wescott
Elsevier/Newnes, http://www.wescottdesign.com/actfes/actfes.html