[Milsurplus] What's With 2,000 Volt, 50-Watt Xmtrs??

[Ray Fantini]

State of the art nineteen thirties design was excessive plate voltage and low plate current, by today's standards at least. Way easier to obtain equal power with low current at high voltage than medium voltage at medium current with old style filter capacitors and rectifier tubes. The 803 is a great tube, think I brought it up before that I have used one in a TBW and heaped great abuse on it without being able to harm it and ask at that time on the reflector and appears no one has seen one fail other than thru sheer stupidity like excessive filament or braking the envelope.
Ray Fantini KA3EKH

-----Original Message-----
From: milsurplus-bounces at mailman.qth.net [mailto:milsurplus-bounces at mailman.qth.net] On Behalf Of mac
Sent: Wednesday, November 17, 2010 1:00 PM
To: David Stinson
Cc: arc5 at mailman.qth.net; milsurplus at mailman.qth.net
Subject: Re: [Milsurplus] What's With 2,000 Volt, 50-Watt Xmtrs??

Fifty watts out with 2KV on the plate is the (suppressor) grid  
modulated specification for the 803.  The tube is good for 200 watts  
out on CW with the same plate supply.  Designers choice, maybe, in the  
case of the AVT-12 to save the weight of a modulation transformer and  
extra circuitry of a plate modulated rig designed around lower  
voltages. Same route taken in the TBW for ex.  Pair of 803s in the TBL  
good for 100W phone and 400W+ on CW as Howard mentioned.  Same deal in  
the TCK with a pair of (control) grid modulated 813s in the PA..

Dennis D. W7QHO
Glendale, CA