Pye 697 chassis - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

Nuvistor · 20th Feb 2014, 1:15 pm

From memory the LT side of the set is fed from a mains TX to a bridge rectifier, located on the line timebase section. The tx in that model will probably have a fuse embedded in the transformer and blow if the tx gets too hot. The BY164 bridge rectifier had a habit of going S/C, replace with 4 separate diodes.

The valves on the CDA panel get hot, there is a mod that reduces the grid leak resistors, mentioned in an earlier post, that can help stop the PCL84 draw grid current.

I did have the sound output IC go in some models, was it a Texas IC with a large heatsink?

Welsh Anorak · 20th Feb 2014, 5:10 pm

Hi
Ah - the grandly named 'Pye Group Colour Television' - as though they would never need to make another! I have that folder as well. One good thing (and there weren't many) about the chassis is that the earlier 691-693 line stack could replace the PCB stage to improve relaibility when the board became a biscuit. Nice to see the inclusion of the more grammatical 'voltage trebler' in the 691 chassis.
Have a look whether you have LT supplies - there should be +30, 20 and 15, then 2 x -20v and -24v. All are fed from the hard-worked BY164 via a couple of resistors.
You may well have trouble sourcing an audio IC, but it's quite possible that someone on here will have a panel going spare. Mind you, that's probably the least of your troubles now!
Glyn

bobbyball · 20th Feb 2014, 5:24 pm

I think the audio chip may be the SN76013, may be mistaken...

Nuvistor · 20th Feb 2014, 6:07 pm

I liked the 691 chassis, did not give me too many problems, reasonable picture when set up correctly, sold a lot of them in various styles.

The 697 was not the same, LTB section as noted and CDA boards burned, the focus control, varicap tuner, station selector buttons and that sound chip, SN76013 does ring a bell, all gave problems. I don't think the CRT's were as good either, the HT thermistor TH 1 or 7 cannot remember, size of a 10p coin used to fall apart.

I presume it was cost cutting that caused some of the problems. We were dealing with mainly Toshiba and Hitachi by that time.

Hybrid tellies · 21st Feb 2014, 2:00 pm

As Glyn has mentioned you need to check the LT supply lines. As well as the BY164 bridge rectifier I can remember some of the LT smoothing capacitors played up as well.
Just a thought if the Sound Output IC is at fault, as indicated by those burnt resistors, this might be dragging the LT lines down. Might be an idea just to disconnect the sound output supply and see what happens.

Welsh Anorak · 21st Feb 2014, 4:50 pm

Hi
We used to see quite a few 205s with good old 691/3 innards. The CDA panels didn't burn up and the line stage just sat there and worked. Even the old BD124 frame stage seemed more reliable. As you say, cost cutting ruined what was originally a good set. Odd - the last Decca Bradfords and Philips G8s were great with the bugs ironed out - Pye seemed to iron the bugs in!
Glyn

20th Feb 2014, 1:15 pm	#21
Nuvistor Dekatron Join Date: Aug 2013 Location: Wigan, Greater Manchester, UK. Posts: 9,433	Re: Pye 697 chassis From memory the LT side of the set is fed from a mains TX to a bridge rectifier, located on the line timebase section. The tx in that model will probably have a fuse embedded in the transformer and blow if the tx gets too hot. The BY164 bridge rectifier had a habit of going S/C, replace with 4 separate diodes. The valves on the CDA panel get hot, there is a mod that reduces the grid leak resistors, mentioned in an earlier post, that can help stop the PCL84 draw grid current. I did have the sound output IC go in some models, was it a Texas IC with a large heatsink?

20th Feb 2014, 5:10 pm	#22
Welsh Anorak Dekatron Join Date: Apr 2005 Location: North Wales, UK. Posts: 6,925	Re: Pye 697 chassis Hi Ah - the grandly named 'Pye Group Colour Television' - as though they would never need to make another! I have that folder as well. One good thing (and there weren't many) about the chassis is that the earlier 691-693 line stack could replace the PCB stage to improve relaibility when the board became a biscuit. Nice to see the inclusion of the more grammatical 'voltage trebler' in the 691 chassis. Have a look whether you have LT supplies - there should be +30, 20 and 15, then 2 x -20v and -24v. All are fed from the hard-worked BY164 via a couple of resistors. You may well have trouble sourcing an audio IC, but it's quite possible that someone on here will have a panel going spare. Mind you, that's probably the least of your troubles now! Glyn

20th Feb 2014, 5:24 pm	#23
bobbyball Octode Join Date: Jul 2011 Location: Stockport, Greater Manchester Posts: 1,215	Re: Pye 697 chassis I think the audio chip may be the SN76013, may be mistaken... __________________ Robert

20th Feb 2014, 6:07 pm	#24
Nuvistor Dekatron Join Date: Aug 2013 Location: Wigan, Greater Manchester, UK. Posts: 9,433	Re: Pye 697 chassis I liked the 691 chassis, did not give me too many problems, reasonable picture when set up correctly, sold a lot of them in various styles. The 697 was not the same, LTB section as noted and CDA boards burned, the focus control, varicap tuner, station selector buttons and that sound chip, SN76013 does ring a bell, all gave problems. I don't think the CRT's were as good either, the HT thermistor TH 1 or 7 cannot remember, size of a 10p coin used to fall apart. I presume it was cost cutting that caused some of the problems. We were dealing with mainly Toshiba and Hitachi by that time.

21st Feb 2014, 2:00 pm	#25
Hybrid tellies Nonode Join Date: Jan 2004 Location: 1966-1976 Coverack in Cornwall and Helston Cornwall. 1976-present Bristol/Bath area. Posts: 2,967	Re: Pye 697 chassis As Glyn has mentioned you need to check the LT supply lines. As well as the BY164 bridge rectifier I can remember some of the LT smoothing capacitors played up as well. Just a thought if the Sound Output IC is at fault, as indicated by those burnt resistors, this might be dragging the LT lines down. Might be an idea just to disconnect the sound output supply and see what happens. __________________ Simon BVWS member

21st Feb 2014, 4:50 pm	#26
Welsh Anorak Dekatron Join Date: Apr 2005 Location: North Wales, UK. Posts: 6,925	Re: Pye 697 chassis Hi We used to see quite a few 205s with good old 691/3 innards. The CDA panels didn't burn up and the line stage just sat there and worked. Even the old BD124 frame stage seemed more reliable. As you say, cost cutting ruined what was originally a good set. Odd - the last Decca Bradfords and Philips G8s were great with the bugs ironed out - Pye seemed to iron the bugs in! Glyn