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

Tech Talk

Forum home - Go back to Tech talk

 Astor D51G/6-CE Stereo Console schematic
« Back · 1 · Next »
 Return to top of page · Post #: 1 · Written at 6:04:08 PM on 4 April 2019.
Damian L's Gravatar
 Location: Waikerie, SA
 Member since 4 April 2019
 Member #: 2342
 Postcount: 1

Hi guys, first time poster long time reader...

I recently unearthed this console in my late Grandfather's garage. The cabinet itself is in excellent condition and powering it on (carefully!) shows the radio fully functional and the turntable (a very nice Garrard AT6 Mk II A) fully operational after a re-lube. It even has a stereo Tape input!

My problem is I have no vertical deflection on the TV. Have swapped the 6GV8 valve and checked a few values of resistors/capacitors etc however I do not have a schematic for it and hoping someone might be able to help. The coil on the yoke measured just over 11 Ohms. The Vertical Linearity control was scratchy and turning the pot allowed a minor momentary change in the deflection. I could also hear the vertical start up at that point. The pot seems to measure a difference in resistance when turned but without a schematic I'm a bit stuck. Hopefully it's just that bad pot.

Hoping to restore this beauty fully electrically so it can take pride of place in my living room.

Thanks all.


 Return to top of page · Post #: 2 · Written at 6:40:41 PM on 4 April 2019.
GTC's avatar
 Location: Sydney, NSW
 Member since 28 January 2011
 Member #: 823
 Postcount: 5750

According to Radiomuseum, the schematic should be in J.R. Publications Television Service Handbook (L.J. Series Vol. 1, Group 6, 1965, Page A68a) -- if anyone has that.

 Return to top of page · Post #: 3 · Written at 7:42:51 AM on 5 April 2019.
Irext's avatar
 Location: Werribee South, VIC
 Member since 30 September 2016
 Member #: 1981
 Postcount: 348

The fact that you got some deflection when moving the pot hopefully means the Vert O/P transformer is good.
They can be the most difficult things to source if they are O/C.
What brand is the unit.

 Return to top of page · Post #: 4 · Written at 7:44:17 AM on 5 April 2019.
Irext's avatar
 Location: Werribee South, VIC
 Member since 30 September 2016
 Member #: 1981
 Postcount: 348

Sorry. I should have read the name on the post heading. Duh!!

 Return to top of page · Post #: 5 · Written at 10:48:30 AM on 5 April 2019.
Fred Lever's Gravatar
 Location: Toongabbie, NSW
 Member since 19 November 2015
 Member #: 1828
 Postcount: 756

I have a few Astor circuits but not that one.
I note that Astor chassis did use a 6BM8 then at series 4 upped to a 6GV8 for the Vertical Sweep.
The first thing that catches my eye with the 6GV8 circuit is the megohm size resistor and height pot off pin one.
I'll bet they have gone high or o/c. That could stop the sweep dead.
That circuit also has cap coupling between the sections of the 6GV8 any leakage would way upset the thing.
After that check all parts for standard tolerance.
Hopefully the oscillator transformer is not open circuit.
If it is then its over to the experts to tell you how to patch around that problem!

 Return to top of page · Post #: 6 · Written at 6:20:00 PM on 5 April 2019.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 4140

I like to avoid TV's, albeit I have touched them and Oscilloscopes. Some of those had paper caps until quite late and a few brands of early polymer type caps had issues as did electrolytics the liked to dry out. Some of the potentiometers were not well thought out. With ones with very high voltage on them, once a bit of carbon dust got loose, they would leak, or flash over.

The worst example of not thought out, was on an oscilloscope with 5KV DC on two of them. These were mounted on the front panel sitting in an insulating grommet. The knob didn't have an adequate skirt, in my opinion. The importer poo pooed my telling them what I thought & were quite rude (I have worked in OH&S). Revenge came in the form of a kid getting bitten by one & I had a certain satisfaction from the parents suing them.

I very much think that Fred is right & leakage testing the NP caps may reveal duds. Some early Polyester caps did like changing their value.


 Return to top of page · Post #: 7 · Written at 3:13:09 PM on 15 April 2019.
Ian Robertson's Gravatar
 Location: Belrose, NSW
 Member since 31 December 2015
 Member #: 1844
 Postcount: 1736

Most TV manufacturers rapidly changed over to plastic caps as soon as they could, usually by the early 60's.

Ducon's early efforts were light blue or green, then they went to a style like the Philips "mustard" caps. Ducon NEVER made paper caps in plastic jackets except for the special dark red radial type they made for Admiral in the 1950s, in bakelite-like jackets.

UCC made "Di-Pol" polyester caps in white jackets.
They also made identical-looking paper caps in white plastic jackets, labelled "Hi-Qual 100". Watch out for these. AWA used lots of them.....

But if your chassis has polyester caps, DO NOT change them. They will be OK.

Polyester caps do have a temperature profile and so should never be used in a horizontal oscillator tank circuit. Styro or mica is the go here.

Did you fix your vertical fault? Loss of voltage to the Height circuit is common in that chassis, open resistor or pot.

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

Sign In

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