90801 Exciter-Transmitter

This is the replacement for the 90800 50 Watt transmitter. Based on a transmitter design that made its appearance in the December 1952 issue of the ARRL QST Magazine. The original Millen schematic indicate a design date of July 1953. As a replacement for the 90800 it does have some similarities, such as size, power, number of tubes and lack of built in DC power source. However, the similarities end there!

Utilizing a 5763 as an oscillator/multiplier circuit feeding a 6146 final amplifier the 90801 is capable of 90 watts CW DC input power. Filament and DC voltages are supplied by a remote power supply. Two major differences between this transmitter and its predecessor is the 90801 uses bandswitched coils vs plug-in coils and has been TVI proofed through extensive RF shielding.

A companion modulator (90831) was also produced for the 90801 transmitter. The modulator is built in a similar sized rack cabinet.

Owner: Don Buska, N9OO