TBM-4 Specifications

accepted by Navy February 19,1940

placed in Service July 15,1941

Power.................... 500 watts on A1 350 watts on AM

Frequency Range.. 2.0 MC and 18.1 MC

B+ requirements.....3000volts from motor-generator

Tube requirements...3 860 tubes,1 861 (Final)

Warmup Time...........1 1/2 hours

Oscillator...................Colpitts

Cathode Keying

The TBM and TDK Transmitters have different Motor-Generators and Modulators, otherwise they are identical