Were there any all-valve PAL colour-TVs?

[G6Tanuki]

Thinking about the "first ICs used in colour TVs" thread leads me to ponder - was any UK manufacturer foolish enough to produce an all-valve UHF PAL TV?

I know there were plenty of all-valve NTSC colo(u)r-tellies in the 'states (they went colour well over a decade before the UK), but NTSC is a bit simpler and by the time PAL got established in Europe the movement-towards-semiconductors was well on the way. Given the poor performance of consumer tuner-stage valves at UHF, and the UK only having colour on UHF, I'd really not wan to have had to deal with low-gain/drifty UHF valve-tuners **and** the complications of an all-valve PAL decoder strip!

[Graham G3ZVT]

I shouldn't think so.
One of the strangest hybrid colour sets from the point of view of surprising places to use valves was the 11" Kuba Portacolor, usually seen here with a Granada Colorette badge.
I think the burst amplifier was a valve, and there were probably more surprises. Can anyone find the schematic?

They certainly made great portable room heaters.

[Biggles]

I remember being given a Philips G6 on a "keep if I can repair" basis when I was about 14. One look inside was enough to put me off (thankfully). It had a fair number of valves and I never worked out the power consumption but it must have been huge. I can't remember if it had transistors too, but looking back I would imagine that the signal processing was probably done with a bucketful of lockfits.

[Nuvistor]

It wasn’t a production set but it’s history is documented well. Started as 405 NTSC, modified to 625 NTSC and again modified to PAL-S.
https://www.radios-tv.co.uk/communit...tal-colour-tv/

https://www.vintage-radio.net/forum/...ad.php?t=36175

[space_charged]

Originally Posted by Biggles

I remember being given a Philips G6 on a "keep if I can repair" basis.

I was given a single standard G6 as a leaving present from a holiday job I had in a TV repair workshop. It had a defective EHT overwind, so I re-designed it to use a tripler. That allowed me to get rid of the shunt stabiliser and the focus rectifier valve.

I used it as my main set for a good many years and fitted it with a re-gunned tube. I still have the set, though not used it in years.

I do remember the colour decoder uses a lot of valves.

[Graham G3ZVT]

Originally Posted by space_charged

I was given a single standard G6 as a leaving present from a holiday job I had in a TV repair workshop. It had a defective EHT overwind, so I re-designed it to use a tripler. That allowed me to get rid of the shunt stabiliser and the focus rectifier valve.

I used it as my main set for a good many years and fitted it with a re-gunned tube. I still have the set, though not used it in years.

I do remember the colour decoder uses a lot of valves.

The PCF200s became difficult to obtain at a reasonable price, and a solid-state module was developed that simply plugged in to the B9A sockets. The results were poor as I remember, and of course, you had to replace all three.

[space_charged]

Yes I have heard of solid state plug in replacements for valves being used. Never seen one let alone had to use one though. I love the magic of valves and have a reasonable stock of NOS set aside to keep my kit going.

I will restore my G6 at some time. It was put away (in warm and dry conditions) in working order so should be fine. Its a 25" version in a very nice (large) wooden cabinet with doors.

I have a spare colour decoder for it in my loft, complete with valves.

[Maarten]

The PL802 was replaced by a solid state module, I think.

The continental version, the K6, didn't have a bucketload of lockfits. Maybe a shot glass of germanium transistors with a BC107 thrown in for good measure. I should look up what was in it exactly, but mostly valves anyway. Power consumption close to 400W.

[Nuvistor]

PL802 definitely had solid state replacement, the picture was not quite as good as the valve version.
Photo in post#11
https://www.vintage-radio.net/forum/...ead.php?t=5509

[usradcoll1]

Originally Posted by G6Tanuki

Thinking about the "first ICs used in colour TVs" thread leads me to ponder - was any UK manufacturer foolish enough to produce an all-valve UHF PAL TV?

I know there were plenty of all-valve NTSC colo(u)r-tellies in the 'states (they went colour well over a decade before the UK), but NTSC is a bit simpler and by the time PAL got established in Europe the movement-towards-semiconductors was well on the way. Given the poor performance of consumer tuner-stage valves at UHF, and the UK only having colour on UHF, I'd really not wan to have had to deal with low-gain/drifty UHF valve-tuners **and** the complications of an all-valve PAL decoder strip!

I remember reading about an all-valve RCA CTC16 from the US converted to PAL using, IIRC, an all valve decoder. It was featured on the US website, "VideoKarma" by Collie 405.
That's how I found this fine website and been hanging around ever since.
Respectfully and always interested, Dave US radcoll1.

[Andy Doz]

Those solid-state replacements ran hotter than the valves they replaced!

[Chris55000]

Hi!

The 11" Granada Portable Colourette wasn't entirely valved as the a.g.c and one or two of the preamplifiers, as well as the U.H.F. tuner, were transistorised!

It had a number of techniques "rolling back" the years in circuit design – there was no LOP stage width stabilisation, and the small deflector coils had to be connected together as the insulation was unable to withstand the boost h.t. voltage, necessitating a fully isolated scan–drive winding on the LOPT.

Note the CRT heater transformer was NOT mains–energised – it was a small current–transformer operated by the heater–chain current!

All this can be inspected from Granada's S.M., very nicely written with Mullard–style text andWireless–World diagram lettering, from here:–

http://www.oldtechnology.net/documen...Colourette.zip

Chris Williams

[ctc15]

Hi I have a RCA CTC16 ntsc all valve colour TV which has been modified to work on 625 lines NTSC and PAL 4.43 Mhz you can see it at this thread https://www.vintage-radio.net/forum/...ighlight=ctc15
Keith

[emeritus]

Keith, that link does not work for me.

[Nuvistor]

https://www.vintage-radio.net/forum/...d.php?t=129430

Is this the link?

[ctc15]

Hi Frank Thank you for the correction.
Keith

[Andrew2]

Originally Posted by Andy Doz

Those solid-state replacements ran hotter than the valves they replaced!

I hated those darned things. They ran hot and had a poor HF response along with lower gain than the real deal.

[terrykc]

We had an all valve Ekco NTSC set at college that I modified for simple PAL. Had to punch holes for two EH90s in that steel chassis!

[Graham G3ZVT]

Originally Posted by Chris55000

Hi!

The 11" Granada Portable Colourette wasn't entirely valved as the a.g.c and one or two of the preamplifiers, as well as the U.H.F. tuner, were transistorised!

It had a number of techniques "rolling back" the years in circuit design – there was no LOP stage width stabilisation, and the small deflector coils had to be connected together as the insulation was unable to withstand the boost h.t. voltage, necessitating a fully isolated scan–drive winding on the LOPT.

Note the CRT heater transformer was NOT mains–energised – it was a small current–transformer operated by the heater–chain current!

All this can be inspected from Granada's S.M., very nicely written with Mullard–style text andWireless–World diagram lettering, from here:–

http://www.oldtechnology.net/documen...Colourette.zip

Chris Williams

4 transistors vs 16 valves,
and, irony of ironies, it's supposed to be a portable!
Can anyone beat that for a consumer set intended for the UK?

[Nuvistor]

I never worked on one but when they came available I did ask why, presume Granada did rent them, perhaps they rented very well.