TheoryTron is a discontinued series of TVs created and marketed by Theorysonic from 1964 to 1989 and it was replaced by the current Nehervia television sets. It is available in NTSC, PAL and SECAM markets.


Theorysonic had entered the television market in 1964 along with the radio.

TheoryTron was criticized for its maximum frequency channels of 12, while its competitors' televisions had 13.

Watching UHF and cable TV channels requires a UHF converter or set-top-box for TheoryTron to watch more channels like channel 23.


Image Model Released Notes
TheoryTron TS-400 TS-400 September 14, 1964 First TheoryTron-branded TV and also Theorysonic's first TV.
TheoryTron TS-415 TS-415 August 13, 1965
TheoryTron TS-421 TS-421 January 22, 1966
TheoryTron TS-430 TS-430 June 26, 1968
TheoryTron TS-470 TS-470 January 2, 1970
TheoryTron TS-484 TS-484 March 13, 1971
TheoryTron TS-492 TS-492 February 22, 1972
TheoryTron TS-500 TS-500 September 14, 1974
TheoryTron TS-520 TS-520 November 12, 1976
TheoryTron TS-535 TS-535 July 3, 1977
TheoryTron TS-550 TS-550 June 23, 1978
TheoryTron TS-575 TS-575 March 13, 1980
TheoryTron TS-600 TS-600 May 9, 1981 First TheoryTron model with stereo sound.
TheoryTron TS-620 TS-620 February 22, 1982
TheoryTron TS-670 TS-670 January 2, 1984
TheoryTron TS-690 TS-690 May 19, 1984
TheoryTron TS-700 TS-700 April 30, 1985 Last TheoryTron TV set.
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