Early 1970's RCA portable.

[Electronic M]

Originally Posted by Phil R

The source I used was a Channel Master digital converter.

I said it wasn't an "Instant On" as the picture doesn't appear immediately as it did on my the solid-state Sylvania GT-Matic I used to have (this one had a pilot on the picture tube).

I don't think the filament on the picture tube remains lit on the RCA. If it does, it still far from being an "Instant-On". But because the other tubes are pre-heated, the set takes about the same time to turn on as a regular transistorized set with a CRT.

There are different kinds of 'instant on' wiring depending on the year and maker. Most tube/hybrid instant on sets ran the heaters at ~half voltage when the set was turned off....There would still be warm up time, but it would be much shorter and would be called "instant on". I've never seen a set that had instant on where that term was literal, though it would not surprise me if some of the solid-state era sets with that feature left the CRT heater on full blast all the time.

I have some 'instant on' sets (proclaimed to be so in the manual) both tube and hybrid, they keep the tubes lit at half voltage when the set is off, and they have a warm up time (a short one).

It is common practice on this forum to refer to any set that, by design, keeps tube heaters lit to some degree while the set is turned off, as an 'instant on' TV set regardless of actual warm up time.