KPO's 50 KW G.E. Transmitter, 1933

KPO's 50 KW transmitter, model RT-152-G, was custom-built by General Electric on contract to N.B.C. The contract also included the construction of the transmitter building, cooling pond and antenna system.
Left Cabinet Image

The driver section of the transmitter was located to the left of the operator. It consisted of three cabinets. The left cabinet was the power and control unit for the driver section. It included the mercury vapor rectifiers for the 600 VDC and 3 KVDC circuits. The center cabinet contained duplicate plug-in crystal control oscillators, two intermediate RF power amplifiers (UX-860 and UV-849), the speech amplifier (2 UV-211) and the modulator (2 UV-849). Modulation took place in the UV-849 intermediat amplifier section. The right cabinet is the 5 KW linear power amplifier, with 2 water-cooled UV-863 tubes.

The 50 KW linear power amplifier was located on the left-hand side of the center section, as viewed by the operator. It utilized two UV-862 water-cooled tubes. To the immediate right of the power amplifier was a monitor speaker and the main 50 KW rectifier secction, which utilized six UV-857 mercury vapor rectifier tubes. There was also a seventh tube which operated as a hot standby,capable of replacing any of the other tubes at a moment's notice.

Transmitter       Transmitter

The panels to the right of the operator were the main control panel for the motor generators and water pump motors, as well as chart recording voltmeters and ammeters. 

   Rear view

Rear views of the transmitter show the 5,000 watt driver stage (above), the output network (below, left) and the high voltage rectifier tubes (below, right).

Rear view   Rear view

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John F. Schneider & Associates, LLC