[HomeBrew] VR Tube regulation 0D3

[Carl]

Amps at contesting.com would be a good place to ask Bob, or the Amplifier forum 
on QRZ.com.

Alpha, Emtron, and others using tetrodes use modern regulation but I dont 
know the voltage specs; I havent gone beyond 400V.

Carl
KM1H

----- Original Message ----- 
From: Rj Mattson
To: homebrew at mailman.qth.net
Cc: km1h at jeremy.mv.com
Sent: Wednesday, April 02, 2014 1:52 PM
Subject: VR Tube regulation 0D3


Hi Carl
I didn't realize how many of my junk box 0D3's have gone sour.
I need to stabilize my cw/am PA 813 screen grid at 750vdc or so to run AB2.
Can your describe or point me to an url that has an easy modern screen 
regulator?
Can a modern IC regulator do 750vdc?
My 813 xmtr is a pre-war am/cw rack job and I am not interested in chopping 
it
up for grounded grid.
The 58 handbook "All purpose 813 amp" ckt has a simple solution for AB2
that leaves my cw/am function intact. You just need gud 0D3's or equiv.
I run my original CE-20A on 160m ssb and need amplification.
Be well
bob...w2ami x wn2ami 1962


 ----- Original Message -----
** From: "Carl" <km1h at jeremy.mv.com>
**
** I guess I'll have to recreate my 813 oscillator to show again it can be
** done and
**  sound fine. I had it running 100W on 80 CW using a couple of real FT-171
** BC-610 crystals and
**  VR tube regulated screen about 30 years ago. ....................
**  Since VR tubes have been steadily reaching end of life, even NOS, this
** time
** Id go
**  with a modern IC regulator and bypass the zener era of regulation.
**
**  Since I enjoy building, especially late 20's and 1930's circuits, 
another
**  was a PP NOS GE VT4A's self excited oscillator at 100W on 80 CW that 
took
** 2
** 1/2
** years of casual operation to confirm DXCC about 3 years ago. That wound 
up
** with regulated DC
**  filaments and an electronically regulated 1000VDC B+.............
**
** Carl
** KM1H
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