The Tuneon. A different type of tuning indicator

[Royboy]

Has anyone come across the Tuneon?
Used in the GEC Fidelity 5 (see trader sheet 54).
It seems to be a variable neon tube.
The glow seems as though it should vary with anode current of the IF amplifier.
My set is dead at the moment so I can't check it out yet.
Regards
Royboy

[Cobaltblue]

Yes Cossor used them in many of their sets.

Pre dates the "Magic Eye"

They are often black from years of use.

http://www.radiomuseum.org/tubes/tube_3184.html

Cheers

Mike T

[ukcol]

Some info in this thread.

https://www.vintage-radio.net/forum/...ghlight=cossor

[Keith]

There's a nice picture of a similar device illuminated at different levels at http://www.magiceyetubes.com/relatives.htm

[Andrewausfa]

I was quite surprised to find it still glowed on my GEC Fidelity AC5.

Andrew

[peter_scott]

See also: https://youtu.be/WEHzuYQcF8U

Peter

[turretslug]

I rather like the principle, it's elegantly simple in an era when active devices were bulky and expensive and had to be sparingly applied and each one had to do as much as possible- a few decades later, incorporating a few dozen transistors in an IC to drive a signal strength meter wouldn't be a problem. The IN-9, IN-13 etc. devices available from ex-Soviet bloc sources seem to use a similar principle.

[Freya]

The HT supply has to be spot on to get a decent range on the tube. Too high and its fully lit, too low and its barely on.

[crackle]

Yes, they work quite well, I have just restored a KB 428 radio with one of these. You can see it in this thread and I did a short video of it working.
http://www.vintage-radio.net/forum/s...1&postcount=28

Mike

[Keith]

Excellent restoration of this lovely set, Mike. Love the stations names windows and the Tuneon indicator.

Thanks for the video. Sadly, I fear that even the associated KB "Rejectostat" aerial wouldn't be effective against your interference. Sounds like you've got LED lighting controllers and/or PLT nearby. Absolutely dreadful - I would have to consider moving!!

[Royboy]

Many thanks to all who answered my query regarding the Tuneon.
The information is much valued
Regards

Royboy

[Mr Moose]

Hello,
Strictly speaking the name Tuneon only applied to the GEC (or MO) version of this indicator but it has now become a generic term for similiar tuning indicators.
As your set is a GEC you presumably have the GEC one, so a data sheet is here http://www.r-type.org/pdfs/tuneon.pdf
Yours, Richard

[Biggles]

I have a Clarke & Smith schools receiver and it uses an indicator which works on a similar principal. It looks like a 15W pygmy bulb but is is neon and has a visible metal halo from the front. As the tuning changes, the ring neon glow dims or brightens. It is the only set I have seen using this type of indicator. I think the neon supply takes the anode voltage change of the IF valve as AGC varies, through a resistor string in the supply. It's quite effective and I have tried to replicate it in home built sets but without much success. I think the HT voltage has to be very stable as was mentioned earlier.
Alan.

[AC/HL]

Is this the one (about half way down the page): http://www.electrojumble.org/Valves_etc.htm

[Marconi_MPT4]

I had a look through some old data books and found information on the GEC Button Tuneon dated 1937.

It would have cost 2s/6d compared with a standard Tuneon Indicator at 4s/-. Data sheet details brief info on setting the operating conditions.

Hope it is legible as the higher quality png was automatically converted to jpg when uploaded.
Rich