On the bench: Sentinel 400TV

[earlyfilm]

Originally Posted by Kamakiri

Tested the tubes, replaced some, but on the schematic on the inside of the set, the 12AT7 in the tuner was crossed out in pencil, and 6C4 written on the diagram. . . . . I don't know if this tuner has been replaced before, but it's marked as being a Sarkes-Tarzian with a stamp date of sometime in Feb 1949.

I'd guess this was a factory substitution of a newer 1949 model tuner that was made when Tele-Tone manufactured your set.

There is a schematic of both your set model and a Tele-Tone made set with the 6C5 tuner at:

http://www.earlytelevision.org/tv_sc..._diagrams.html

To find what probably is your ST tuner, look at the Airline 94SE-3018A schematic on the same page.

James