[BC] The last of the tube 1000 watt transmitters

[John Lyles]

But that PDM transmitter WAS plate modulated. Sort of. The plate was 
tied to ground for DC, and the cathode was tied to a varying source 
of negative HV, provided by the switch tube through a LP filter. This 
was essentially the same thing as plate modulation except without a 
transformer or class B P-P audio stage. Perhaps a better title is 
"the last of the class B plate modulated 1000 watt tube 
transmitters". OK I am beating a dead horse here. But with a glass 
window to look in at three (not four) 3-500Z triodes, the Power 
Pebble 1 kW was just as hollow state as a four banger with iron in 
the audio. Check here for the original brochure:

  http://www.jtml.info/314R1/314R1-1.html

Best Regards,
John L.

 > From: Art Reed <areed21774 at aol.com>
 >
 > Perhaps the thread should really be titled "The last of the Plate
 > Modulated 1000 watt tube transmitters".
 >

 > From: dynotherm at earthlink.net
 >
 > You may be correct, although I thought the Power Rock moniker
 > was applied only to the 820D's and E's (5 kW).
 >
 > I guess it is just me, but I don't think of things like the
 > MW5's etc as real tube transmitters (although they are). To
 > me a real tube box not only has tubes but is high level
 > modulated by a push-pull pair and IRON. IOW, just like
 > back in the day. <g>

 > Phil Alexander, CSRE, AMD