Granada Television Brochure, 1970s
Long Gone UK TV Shops
Memories of a Derwent Field Service Engineer
PYE Australia Circa 1971
Radios-TV VRAT
Fabulous Fablon
Thorn TX10 Chassis
Crusty-TV Museum, Analogue TV Network
Philips N1500 Warning!
Rumbelows
Thorn EMI Advertising
Thorn’s Guide to Servicing a VCR
Ferguson 3V24 De-Robed
Want to tell us a story?
Video Circuits V15 – Tripler Tester
Thorn Chassis Guide
Remove Teletext Lines & VCR Problems
Ceefax (Teletext)
Suggestions
Website Refresh
Colour TV Brochures
1970s Lounge Recreation
CrustyTV Vintage Television Museum
Linda Lovelace Experience
Humbars on a Sony KV2702
1972 Ultra 6713
D|E|R Service “The Best”
The one that got away
Technical information
The Line Output Stage
The map
Tales of a newly qualified young engineer.
Tales of a Radio Rentals Van Boy
Sanyo SMD
Disastrous Company Rebranding
1969 Philips G22K511
Memories Of The TV Trade
Crazy house
Dirty TV screens
Dual Standard and Single Standard CTV’s
Radios-TV on YouTube
The Winter of 62/63
A domestic audio installation
1979 Ferguson Videostar Deluxe 3V16
Music centre modifications
Unusual record player modification
B&K 467 Adapters
Mishaps In The Trade
1971 Beovision 3200
1971 Bush CTV1120
Granada Television Brochure, 1970s
Long Gone UK TV Shops
Memories of a Derwent Field Service Engineer
PYE Australia Circa 1971
Radios-TV VRAT
Fabulous Fablon
Thorn TX10 Chassis
Crusty-TV Museum, Analogue TV Network
Philips N1500 Warning!
Rumbelows
Thorn EMI Advertising
Thorn’s Guide to Servicing a VCR
Ferguson 3V24 De-Robed
Want to tell us a story?
Video Circuits V15 – Tripler Tester
Thorn Chassis Guide
Remove Teletext Lines & VCR Problems
Ceefax (Teletext)
Suggestions
Website Refresh
Colour TV Brochures
1970s Lounge Recreation
CrustyTV Vintage Television Museum
Linda Lovelace Experience
Humbars on a Sony KV2702
1972 Ultra 6713
D|E|R Service “The Best”
The one that got away
Technical information
The Line Output Stage
The map
Tales of a newly qualified young engineer.
Tales of a Radio Rentals Van Boy
Sanyo SMD
Disastrous Company Rebranding
1969 Philips G22K511
Memories Of The TV Trade
Crazy house
Dirty TV screens
Dual Standard and Single Standard CTV’s
Radios-TV on YouTube
The Winter of 62/63
A domestic audio installation
1979 Ferguson Videostar Deluxe 3V16
Music centre modifications
Unusual record player modification
B&K 467 Adapters
Mishaps In The Trade
1971 Beovision 3200
1971 Bush CTV1120
Sobell T192 again.
"Your telly's gone pop and there's no sound" shouts SWMBO from the dining room.
Damn....
It's my favourite set. The Sobell T192 fitted with wonderfully bright and sharp AW43-88 tube. Circuit can be found here http://www.technicalibrary.radios-tv.co ... =23&sort=0
I cart it into the workshop and remove the back. I extensively re-capped the set some time ago, and it's been well behaved until today.
A quick wiggle around valve holders and pop, up comes some sound, accompanied with some vision on sound to. It's V9 a PCL84. Swap a new one in, a quick tweak of the sound IF transformer, and all's well... for a minute or so. Crackle, pop and no sound....
Out with the scope and trace the audio from MR3, an OA81 Audio detector. Yep, fine here, moving along to the grid of V7b , yes good here too. Anode of V7b is good too, HT and audio in quantity. Over the other side of the chassis to The grid of the pentode bit of V9 (PCL82) and audio is fine, but sitting on a nasty 43V.. where's that coming from? C71. That's were. Replaced. Plenty of audio. But my video buzz is back.
Just about to set about aligning the IF , when the picture balloons and fades away! OK. It's going to be like this is it?!?! Turn the brightness down and the pictures back but ballooning all over the place.
Open up the line output screen and replace the DY86. Switch back on. EHT now steady, but not enough width. Pull PL81, and it's looking very brown and unpleasant. New one in and width better but still not quite enough, but back to the IF for now ....
A complete re-alignment as described in the manual didn't provide any improvement. Coils tweaked, capacitors checked, none improving the rejection of vision from audio. Removal of the OA81 , and inserting audio here proved it wasn't pickup from the frame stage or elsewhere. Re-inserting the OA81 and no sound!
I replaced the OA81 with a new one, and sound returned! A few tweaks again of the sound IF and performance was restored!
Low width failed to improve with a new PY81, but thankfully responded to the "set width" tags getting set up on the lopt.
.... now where's that VT4 .....
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