[Milsurplus] BC-654/SCR-284

[Robert Nickels]

On 6/28/2011 8:20 AM, Ray Fantini wrote:
>   Second, is a 307 a three volt 807? How do you build a beam power tube that works on three volts and a battery feed?
I can help a little with this question Ray.   The VT-225 aka 307A, 
RK-75, or CV2612 is a transmitting pentode described as "a 306A with 
quick-heating 5.5 volt 1A filament" in Ludwell Sibley's "Tube Lore".   
The plate is rated at 15 watts, with the 3rd grid brought out to a 
separate pin for suppressor grid modulation, as was done in the 
BC-654.   They were made by Western Electric, Ken Rad,  Raytheon, 
National Union and Sylvania.  Audiophiles have become enamored of them 
(especially those of rare and wonderous "WE" heritage"), so you can 
guess what impact that's had on tube prices

Transmitter and receiver power was separate, with the receiver able to 
operate from a battery and vibrator power supply, while the transmitter 
required a hand crank generator or dynamotor power supply.   .  Very 
cool radios with a great history.

73, Bob W9RAN