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Early Electronic Television

General Electric HM-171 and HM-185 Technical Information

Television: Three channel (50-90 mHz) superhetrodyne. 5 inch CRT (5BP4) tetrode. Electrostatic focus and deflection, approx. 30 degrees.

 

Function
Quan. Type
Notes
   
Oscillator/Mixer 1 6F8
Video IF Amplifier 2 6AB7 Video (9.5-12.75 mHz), audio (8.25 mHz)
Video IF Amplifier 1 6AC7  
Video detector/amplifier 1 6F8
Video output/sync separator 1 6F8
Horizontal (line) oscillator 1 6N7
Horizontal (line) output 1 6F8
Vertical (frame) oscillator 1
6N7
Vertical (frame) output 1 6F8
Audio IF amplifier 2 6SK7 8.25 mHz
Audio detector 1 6H6 HM-171 only
Audio detector/amplifier 1 6SQ7 HM-185 only
Audio Output 1 6V6 HM-185 only
Rectifier (HT) 1 5U4
High Voltage (EHT)  1 2X2 2500 VDC

Service notes

Technical information