Howdy,


A 6L6 immersed in a can of peanut oil is an old timey final, smells
good too.


73,
Grumpy
(Who can't get news express to work withg AIOE anymore.)

ken scharf wrote:
Fred McKenzie wrote:
In article
,
JIMMIE wrote:

I am considering an 807 as a replacement

Jimmie-

Just how simple will this transmitter be? My first novice transmitter
was built from an ARRL publication back in the 50s. The specification
was for a single 6V6, used as a crystal oscillator with output coupled
to the antenna.

I found I could get more power with a 6L6 plugged into the same socket.
Along the way to getting more power, I found that crystal current would
increase to the point where the crystal would fracture!

If you use a 807 or 1625, I hope you will have a lower power oscillator
driving it. Something like a 6AG7 would make a nice crystal oscillator,
and should have sufficient output to drive an 807.

73,
Fred
K4DII
The 6AG7 - 807 combo is a classic. E. F. Johnson sold a 50 Watt Novice
transmitter in the '50's with this tube line up (also a 5R4GY rectifier
IIRC). Other tubes that have been used as the oscillator/driver were
the 6CL6, 12BY7, 6GK6, and 5763.

On Dec 10, 9:27*pm, "
wrote:
Howdy,

A 6L6 immersed in a can of peanut oil is an old timey final, smells
good too.

73,
Grumpy
(Who can't get news express to work withg AIOE anymore.)



I tried doing that with a 4cx250 once. Never got it to work. Looking
back on it I should have mounted the base of the tube to the paint can
lid and hung it in the bucket upside down.
Hmmm, might be something fun to try this winter.

Jimmie

JIMMIE wrote:
On Dec 10, 9:27 pm, "
wrote:
Howdy,

A 6L6 immersed in a can of peanut oil is an old timey final, smells
good too.

73,
Grumpy
(Who can't get news express to work withg AIOE anymore.)



I tried doing that with a 4cx250 once. Never got it to work. Looking
back on it I should have mounted the base of the tube to the paint can
lid and hung it in the bucket upside down.
Hmmm, might be something fun to try this winter.

Jimmie
I recall an article on using a 4cx250 with water cooling. Actually it
sat upside down in a pool of water which was allowed to boil off from
the heat of the tube. Which means the tube didn't get hotter than 100
degrees C (until all the water boiled away). This is known as 'vapor
phase cooling'. Believe it or not you can cool a tube with STEAM!