Pye 405 line colour TV

[FERNSEH]

Split from this thread:-

https://www.vintage-radio.net/forum/...634#post107634

Graham. Station X. Forum Moderator.

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My Pye 405 line colour TV set must at one time received colour transmissions from AP.

Someday I might demonstate NTSC pictures on it again.

I just need to find the time to construct a 625PAL to 405NTSC for the set.

DFWB.

[ppppenguin]

Originally Posted by FERNSEH

I just need to find the time to construct a 625PAL to 405NTSC for the set.

David, there are several ways to approach that problem.

• Ask David Robinson nicely if he will lend you his converter with 405 NTSC output.
• Persuade Darryl that he really would like to do a 405 NTSC version of either Aurora. He and I both think it's feasible without hardware changes though it might be quite a lot of work.
• DIY, possibly using Kat Manton's methods hooked up to an NTSC coder.

[FERNSEH]

Originally Posted by ppppenguin

David, there are several ways to approach that problem.

Hi Jeffery,
Good advice. While I'm still in this shop trying to fix modern junk for next to nothing I'll never get around to constructing a converter for the set.
So, under the present conditions nothing will ever get done.

The answer? Swallow my pride and buy in the equipment from someone else.

DFWB.

[David_Robinson]

Originally Posted by ppppenguin

Ask David Robinson nicely if he will lend you his converter with 405 NTSC output.

I'd be glad to do this as long as I can borrow another converter, preferably an Aurora, for the duration. It would be great to prove that the colour from my unit is actually correct!

I have a Bush dual standard colour set with the idea of hanging a separate NTSC decoder onto it for 405 colour. I think this would be preferable to modifying the set's own decoder and destroying the authenticity of the set in the process. The set does need a lot of work however before I reach that stage.

[Panrock]

Originally Posted by FERNSEH

My Pye 405 line colour TV set must at one time received those transmissions from AP.

David, does it have a turret tuner? Can it receive Channel 5 ?


S

[FERNSEH]

Hi Steve,
The 13 channel tuner unit is a similar to the one used in the Pye "Luxury 17" model of 1955 as are the sound and vision IF amplifiers.

The Pye colour set employs two parallel connected PL36s and PY81s in the line output stage.

The colour circuits resemble those of the RCA CTVs models CT100 and 21CT55.

DFWB.

[FERNSEH]

Originally Posted by David_Robinson

I'd be glad to do this as long as I can borrow another converter, preferably an Aurora, for the duration. It would be great to prove that the colour from my unit is actually correct!

Hi David,
You are most welcome to try out your converter on the Pye CTV sometime, but first I must estabish if the set still works.

I will be contacting Daryll about the possibility of customising one of the Aurora converters for NTSC 405.

DFWB.

[Dave Moll]

See: http://www.earlytelevision.org/pye_e...tal_color.html

[FERNSEH]

Also Ian Watson's site: Early photography and 405 television.

Click on 1956CTV

http://www.jdwn.freeserve.co.uk/eps405tv/index.htm

DFWB.

[beery]

Hi All,
there is also a picture of the set displaying colour bars on the site I created for FERNSEH at:-
http://freespace.virgin.net/brian.beer/pyentsc.htm

For the rest of the site go to:-
http://freespace.virgin.net/brian.beer/index.htm

Cheers
Andy

[Dave Moll]

Returning to the topic of Fernseh's set, in response to a comment made by him (in the thread about 405-line colour in Scotland) about whether there are other sets than his, I seem to remember John Trenouth saying that the Media Museum in Bradford (formerly the NMPFT) has at least two 405-line colour sets, though I'm not sure they're in working order.

Unfortunately, I was unable to confirm this when I went on a backroom tour at the museum last autumn, as the tour was led by the curator of photography (who didn't know anything about the televisions) and there was no curator of televisions at the time

[Ray Cooper]

ppppenguin:

The 405 system seems to have acquired and discarded lift at least once over the years... The only reason I can see for having lift is to help the H flyback blanking of early sets...

There used to be a peculiar defect on some early Band I TXs that caused an effect commonly called 'rope'. This was a hazy and wavering band of faint light roughly up the centre of the picture. It was caused by overshoots on the rising edge of sync pulses - usually due to faulty clamp action in the modulator - and was exacerbated by the absence of flyback blanking in receivers. It resisted solution for some time, and the quick fix was the 5% lift, technically called 'pedestal', which bodged the problem away. In later years, the TX problem was solved, and most early sets without flyback blanking had died the death, so 'pedestal' was abolished.

Of course, the viewer could produce 'rope' at any time he desired, by mistuning the local oscillator so producing overshoots. But control of this was felt to be in the viewer's hands rather than the broadcasters.

Getting a bit OT, this...

[SWB 18]

I thought that the attached scans of a Pye leaflet I have might be of interest.

It appears to come from a demonstration of colour television given by Pye, possibly at a Radiolympia?

Phil.

[Dave Moll]

Although it doesn't seem to have a date, it refers in one paragraph to 1931 and "nearly twenty years", which would put it around 1950.