GE HM-275-3A Prewar Television


Year: 1939 Deflection: Magnetic
Production: 75 Focus: Electrostatic
Original Price: $795.00 HV Type: AC Mains
Tube Count: 30 CRT: 12AP4


General Electric HM-275-3A from 1939, 12" CRT, mirror in lid, 5 channel push button tuner, 3 band radio. This set originally cost $795. ($9,618. in today's money), when the average yearly salary was $1,800.

The model HM-275-3A was a very limited production set , it is said that only 75 units were manufactured in 1939 and none were sold. After the new TV standards were implemented in 1941, this model was modified for FM audio and the sync and video circuits were also modified, the set was relabeled and sold as the Musaphonic Model 90. 

Presently there are only two Model 90 and two HM-275 sets known to exist.


This set came from the GE facilities in Portsmouth, VA and probably is the reason it still carries the HM-275-3A labels and has the original AM TV audio along with the original 1939 electronic design. From information I have been able to gather, this set was  restored to operating condition in 1982 by the GE model shop to be placed in a company museum. The cabinet veneers are from a rare wood called Sapeli. It measures 39"H x 42"W x 21"D closed.

I have received some additional history on this set. I was able to track down the man who worked in the GE model shop in the early '80's. He told me that six televisions were shipped to the Portsmouth, VA plant from the Louisville plant to  be restored and used in an exhibit at the 1982 or 1983 Consumer Electronics Show, not at a museum as I was originally told. The exhibit was called "The History of Television". After the show the sets were returned to Portsmouth, and because there was no place to store them they were to be disposed of, I guess that's when this set was taken home by one of the employees. I haven't had any luck tracking down any articles about the Consumer Electronics Show for that period of time, I would appreciate any information about this show.


The RF chassis, this chassis contains the 5 channel RF tuner, video & audio IF circuits, horizontal & vertical oscillators. This is the only prewar set that uses an RF amplifier stage.

Bottom view of the RF chassis.


The three tube 5 channel tuner, RF amplifier, Mixer, & Oscillator

Mechanical linkage for the fine tuning control


This chassis contains the low voltage & high voltage supplies, and the audio output. The high voltage supply uses a 60 cycle transformer, with 879 (2X2) rectifiers in a voltage doubler, supplying about 6,500VDC to the CRT.

Low voltage supply uses parallel 5U4G's, the audio output is a 6L6G.

The electrolytics are not original to the set, probably replaced during the GE restoration in 1982.


The 12AP4 CRT in it's protective cardboard shield.

The GE logo on the original CRT bulb. RCA supplied the CRT's to GE, the story goes that RCA sent all their borderline tubes to GE and used the best in their TRK-12 sets.



The radio and television control panels


The tube layout and model label from back of set which still carries the original 1939 model number and tube lineup.






These are two pages from a 1939 GE TV sales brochure showing the top of the line HM-275-3A, notice the viewers in their evening wear. Click on the page to see a full size scan.

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