Welcome to Australia's only Vintage Radio and Television discussion forums. You are not logged in. Please log in below, apply for an account or retrieve your password.
Australian Vintage Radio Forums
  Home  ·  About Us  ·  Discussion Forums  ·  Glossary  ·  Outside Links  ·  Policies  ·  Services Directory  ·  Safety Warnings  ·  Tutorials

Vintage Television

Forum home - Go back to Vintage Television

 Can anyone identify a late 1960's Pye TV set
« Back · 1 · 2 · Next »
 Return to top of page · Post #: 16 · Written at 4:30:36 PM on 10 October 2018.
Ian Robertson's Gravatar
 Location: Belrose, NSW
 Member since 31 December 2015
 Member #: 1844
 Postcount: 1490

That Pye push-in-pull-out width control was last used on the hybrid T23 chassis which may well have been used in that cabinet style. This one is more likely to be an all solid state T26.

The T23 hybrid chassis was the last to have unregulated deflection, so width would have been affected by mains voltage. That might explain the overscan.

The Pye T20 I grew up with had the same width control. I recall spending some time in the early 60s lining it up "perfectly" with just enough overscan to cover the push-through bonded faceplate 23HP4 CRT using the Marconi resolution chart transmitted by Ch9 early in the morning. It held its width and height quite well as I recall.

Some of those "twin speaker" models were actually only fitted with one speaker! Our console T20 had a little cheap 4" Magnavox speaker in the middle of its huge baffle. It still sounded OK, surprisingly.


 
 Return to top of page · Post #: 17 · Written at 3:04:45 PM on 11 October 2018.
NewVista's avatar
 Location: MilwWI, US
 Member since 10 May 2013
 Member #: 1340
 Postcount: 653

Ah, I see, it must have been the hybrid that I worked on - would have been around 1969 to 1971?


 
 Return to top of page · Post #: 18 · Written at 3:53:45 PM on 11 October 2018.
Ian Robertson's Gravatar
 Location: Belrose, NSW
 Member since 31 December 2015
 Member #: 1844
 Postcount: 1490

The all solid state T26 chassis was well and truly in production in those years. Your T23 would have been a bit older. It had 4 tubes in the chassis and 2 in the tuner. From memory the width coil on the T23 was inside a plastic moulding that held the EHT stuff as well.

Oh yes, both chassis used a strange horizontal linearity control with two magnets attached to either end of a shallow U shaped bracket that you rotated around a ferrite core on which was wound a small inductor in series with the yoke. The magnets would saturate the core to a variable degree and affect the shape of the horizontal scan.

This same arrangement continued into the T29, T30, T30C and T34 colour chassis.

All flyback transformers were covered in a black bitumen-like material which was known as "Berry-Wiggins compound". They looked as ugly as sin but it was very unusual for one of these to fail.


 
 Return to top of page · Post #: 19 · Written at 1:25:45 AM on 12 October 2018.
NewVista's avatar
 Location: MilwWI, US
 Member since 10 May 2013
 Member #: 1340
 Postcount: 653

Some of those "twin speaker" models were actually only fitted with one speaker!

The one I encountered could well have only had one speaker and a fake grille, because my (unauthorised by the owner) tampering with that set was just focused on quickly finding the scan adjustments. When the very convenient ferrite stick (had a knob attached) was found, it was like "Jackpot", no more overscanned picture to annoy me - not subtle either, as its width was really blown out.


 
 Return to top of page · Post #: 20 · Written at 1:38:55 PM on 12 October 2018.
Ian Robertson's Gravatar
 Location: Belrose, NSW
 Member since 31 December 2015
 Member #: 1844
 Postcount: 1490

That little black knob on the end of the ferrite stick was actually a cap for a squeeze tube, e.g. toothpaste! The old style, made from black bakelite. Glued on with epoxy.
No point in tooling up for something you can buy off the shelf for 1 cent!

That "width" control was more accurately described as a "size" control, it varied the flyback tuning and hence the EHT.


 
« Back · 1 · 2 · Next »
 You need to be a member to post comments on this forum.

Sign In

Username:
Password:
 Keep me logged in.
Do not tick box on a computer with public access.