Let's talk about channels C and F please.
 

This is on a mid-60s CCIR Sony set. I've looked all over the place and can't figure out what these channels are. Lots of references to "E" channels, which seem to be kinda like "bis", and which this set does not seem to have.

https://i.imgur.com/GmETM34l.jpg

Can anyone tell me what these are? Or were?

Thanks.

alan

Model number?

.

This is a 9-51UET. It was made in Barcelona by KOSMO ELECTRONICA under license from Sony in ~1968. There appear to be several variants of this set sold in Europe, all with a different last letter in the model number, but the others were built in Japan by Sony.

Assuming it was made in Barcelona for that region I'd recommend looking at period literature on the RF spectrum there. Those channels may have originally been for some public service like police 2-way radio placed in the middle of the TV band that later moved to different frequencies and got repurposed into TV channels. If the TV channel numbering was around long enough when extra midband channels were added it would make sense to give the new channels letters rather than disturb existant branding and make tuning old sets confusing.

Another possibility is those channels never carried TV in that market, but it was cheaper to buy a tuner made for many countries and give the channels not used in the area letters corresponding to their non-TV use.

The Sony set covers the standard European system B channels 2 to 11.
Italy used the same system but the channels went A,B,C etc.with slightly different frequencies but within range of the fine tuner.Italy channel A approximates to European Channel 3.
Exceptions are channel C(83 odd MHz approximately US channel 6) and channel F
on highband.
Wikipedia graphic shows the frequencies.
https://en.m.wikipedia.org/wiki/Tele...AVHF_Usage.svg

I have the same TV made by Sony in Japan
and it has exactly the same tuner knob layout.
The North American Sony equivalent was th ae Sony TV9-51UW.