Museum Hours:

Saturday 10-6

Sunday 12-5

Early Electronic Television

HMV 904/905 Technical Information

Television: Single channel superhetrodyne. 45.0 mHz video, 41.5 mHz audio. The 904 uses a 5 inch CRT (Emiscope 3/1) triode and the 905 uses a 7 inch CRT (Emiscope 3/2). Magnetic focus and deflection, approx. 45 degrees.

Radio: Short (16-52 meters), Medium (200-550 meters) and Long (750-2000 meters) wave bands.

Function
Quan.
Type
Notes
  
RF amplifier 1 MSP4
Oscillator/mixer (frequency changer)   1 X41C 37 mHz local osc. frequency
IF Amplifier 1 KTZ41 Video (5.5-8 mHz), audio (4.5 mHz) and radio (456 kHz)
IF Amplifier 1 KTZ41 Video and audio
IF Amplifier 1 KTZ41 Video only
Video detector/amplfier 1 MS4B
Sync separator 1 KTZ63
Horizontal (line) oscillator 1 KTZ63
Horizontal (line) output 1 KT63
Vertical (frame) oscillator 1 KTZ63
Vertical (frame) output 1 KT63
Audio detector and AVC 1 MDH4
Audio Output 1 KT41
Rectifier (HT) 1 U52
High Voltage (EHT)  1 U17 2500 VDC

Service manual