Globe King models.
Models 500 and 500A without VFO, later models 500B and 500C with built-in VFO.
VFO tubes: 6AU6 6CB6 0A2. Also the 6V6 was replaced by a 6AG7 and keyer 12AU7 added.
Latest 500C using 4-400A as final amplifier instead of 4-250A.
GE data sheet for the 6AG7 Pentrode, MT8 - Metal tube Octal socket. (EIA 8Y)http://www.r-type.org/pdfs/6ag7.pdf
GE data sheet for 6V6 Beam Pentrode, GT - Glass tube.http://www.r-type.org/pdfs/6v6gt.pdf
There are differences for the screen (grid 2) connection: Pin 4 for 6V6, Pin 6 for 6AG7.
Globe King 500: transmitter; Advertisement: JUL 1954 QST; price $675.00 wired;
500 watts AM, 500 watts CW, 500 watts SSB (with external exciter);
160 thru 10 meters; bandswitching. http://amfone.net/Tech/wrl/king500.htmRF Section
: 6V6 crystal oscillator, 6146 buffer, 4-250A final, 6X5 and 5Y3 low voltage rectifiers.Modulator
: 6SJ7 speech amplifier, 6C5 amplifier, 6C5 amplifier, 6L6G driver,
push-pull 5514 modulators, 5Y3 low voltage rectifier, pair 816 high voltage rectifiers. Power Supply
: 5U4G low voltage rectifier, pair 866A high voltage rectifiers.
Crated shipping weight 270 lbs.