Bush TV62 - UK Vintage Radio Repair and Restoration Discussion Forum

technotel · 28th Apr 2021, 8:24 pm

Hi guys
Picked this beautifull TV62 up. Its clean as a whisle apart from the slighty cracked bezel around crt. The case is mint, no cracks or chips. The inside is untouched. Plenty of dust and no rusting on the chassis. I paid £140 for it. was it a good find? Cant wait to wind it up on the variac ?? Or should there be cold checks I should do first? The underside looks very clean.I guess a bulk recapping will be in order?
Thanks for looking
Terry

Mr Hoover · 28th Apr 2021, 9:17 pm

If you can,check the crt for emission
and any sign of heater cathode leakage.
The crt's in these sets can suffer from a partially
shorted heater, symptom being that 6.3 volts
isn't developed across the heater in the series chain and it looks rather dim.
Personally I wouldn't run it up
without changing some capacitors
in the time base section..
If you do, remove the capacitor across the mains input, they can short and blow the fuse.
There's a good series of videos
on a TV62 restoration by Onjoj
(line scan 87 in this forum).
https://youtu.be/fw_Vnol7AwE

high_vacuum_house · 28th Apr 2021, 9:57 pm

I would do a few cold and visual checks first and snip out the mains suppression wax capacitor. If I knew it had been dry stored for a decent amount of time I would attempt to wake it up first with a lamp limiter before attempting to recap or disturb anything on the chassis.

It may be well likely that the set was stored in working order and come up with a "raster of sorts" fine. It is easy to disturb things before getting "first light" and then you don't know if it is an original fault or a "new mistake caused" fault.

It is for this reason that getting first light on the CRT is important as this will tell you a lot about what is going on in the various stages of the receiver. It will also prove that you have a working CRT and LOPT which if faulty could make the restoration difficult.

Bulk changing of capacitors in one go is not recommended as unintentional faults can easily creep in if say one of the capacitor leads is inadvertently hooked on a wrong tag will take you on a long and wild goose chase to locate. Change one or 2 at a time and then power back up to check the results. Thus if you then discover a new fault it should be easy to discover.

Once first light is obtained I would change capacitors in the following sequence stage by stage. This should show a progressive improvement in the receivers performance. Getting the line and frame timebases working correctly first will then be able to show up issues in the IF and video stages.

Line timebase
Frame timebase
Video output and sync separator
Sound output stages
IF stages
RF stages

Christopher Capener

p.s I presume you have an Aurora or other standards convertor to be able to display a test card as this will make setting up of the timebases much easier.

PYE 405 · 28th Apr 2021, 10:00 pm

Hi Terry, that looks a nice set indeed. The video by Line scan 87 is excellent and well worth watching. Good advice there above from Christopher too.

I would be very careful about applying any power without some careful checking first. It could save you tears if there are any serious faults. The main HT electrolytics really ought to be checked and re-formed. If not, you could ruin them and the PY82 rectifier valves. Even using a variac is no good because the rectifiers will only start to conduct with appreciable voltage to the heaters. You will have little control of the current unless a lamp limiter is used.

A while back I restored a Bush TV53 which has the same chassis as the TV62. Here below is a link if you are interested....
https://www.radios-tv.co.uk/communit...s/bush-tv53-2/

technotel · 28th Apr 2021, 10:33 pm

You guys are magical. I take all this advise with great excitement. Thank you all for these tips...Awesome. I will follow all line by line. And let you know how I get on.
Terry

Duke_Nukem · 28th Apr 2021, 10:44 pm

Pay particular attention to the wires under the power chassis. There's a number that run under a tag strip and on the TV62 I worked on the insulation was crumbling to dust and where they go through the chassis to the top side of the chassis they were close to shorting together. A major pain as to access the wires requires lifting the tag strip, which meant unsoldering a lot of bits. Ended up doing a mass cap and wire change, I was amazed it actually worked afterwards.

I'm not a fan of using a variac; effectively you are under-running the valves, particularly the HT rectifiers (as mentioned by PYE 405) and they work hard enough as it is. Reform / check HT electrolytics, ensure there are no HT shorts, snip mains filter cap, check voltage taps, add a meter to monitor the HT rail. Then give it the beans, though to be honest I always change the grid cap coupling to the LOP bottle and change the boost cap. Regarding the LOP transformer, whilst I got lucky and mine has been fine if I had my time again I'd have run some DC through it to ensure it was nicely dried out first.

TTFN,
Jon

Mr Hoover · 29th Apr 2021, 7:39 am

Check the condition of the long wires running very close to the cabinet foil screening to the above right of the line output can.
They get gently cooked by the line output stage and the proximity of the foil can cause "interesting" intermittent effects.

28th Apr 2021, 8:24 pm	#1
technotel Pentode Join Date: May 2018 Location: High Wycombe, Buckinghamshire, UK. Posts: 135	Bush TV62 Hi guys Picked this beautifull TV62 up. Its clean as a whisle apart from the slighty cracked bezel around crt. The case is mint, no cracks or chips. The inside is untouched. Plenty of dust and no rusting on the chassis. I paid £140 for it. was it a good find? Cant wait to wind it up on the variac ?? Or should there be cold checks I should do first? The underside looks very clean.I guess a bulk recapping will be in order? Thanks for looking Terry Attached Thumbnails

28th Apr 2021, 9:17 pm	#2
Mr Hoover Hexode Join Date: Jan 2007 Location: Faro, Portugal Posts: 269	Re: Bush TV62 If you can,check the crt for emission and any sign of heater cathode leakage. The crt's in these sets can suffer from a partially shorted heater, symptom being that 6.3 volts isn't developed across the heater in the series chain and it looks rather dim. Personally I wouldn't run it up without changing some capacitors in the time base section.. If you do, remove the capacitor across the mains input, they can short and blow the fuse. There's a good series of videos on a TV62 restoration by Onjoj (line scan 87 in this forum). https://youtu.be/fw_Vnol7AwE

28th Apr 2021, 9:57 pm	#3
high_vacuum_house Octode Join Date: May 2003 Location: Belper Derbyshire Posts: 1,935	Re: Bush TV62 I would do a few cold and visual checks first and snip out the mains suppression wax capacitor. If I knew it had been dry stored for a decent amount of time I would attempt to wake it up first with a lamp limiter before attempting to recap or disturb anything on the chassis. It may be well likely that the set was stored in working order and come up with a "raster of sorts" fine. It is easy to disturb things before getting "first light" and then you don't know if it is an original fault or a "new mistake caused" fault. It is for this reason that getting first light on the CRT is important as this will tell you a lot about what is going on in the various stages of the receiver. It will also prove that you have a working CRT and LOPT which if faulty could make the restoration difficult. Bulk changing of capacitors in one go is not recommended as unintentional faults can easily creep in if say one of the capacitor leads is inadvertently hooked on a wrong tag will take you on a long and wild goose chase to locate. Change one or 2 at a time and then power back up to check the results. Thus if you then discover a new fault it should be easy to discover. Once first light is obtained I would change capacitors in the following sequence stage by stage. This should show a progressive improvement in the receivers performance. Getting the line and frame timebases working correctly first will then be able to show up issues in the IF and video stages. Line timebase Frame timebase Video output and sync separator Sound output stages IF stages RF stages Christopher Capener p.s I presume you have an Aurora or other standards convertor to be able to display a test card as this will make setting up of the timebases much easier. __________________ Interests in the collection and restoration of Tefifon players and 405 line television Last edited by high_vacuum_house; 28th Apr 2021 at 10:03 pm.

28th Apr 2021, 10:00 pm	#4
PYE 405 Pentode Join Date: Dec 2009 Location: Chatteris, Cambridgeshire, UK. Posts: 176	Re: Bush TV62 Hi Terry, that looks a nice set indeed. The video by Line scan 87 is excellent and well worth watching. Good advice there above from Christopher too. I would be very careful about applying any power without some careful checking first. It could save you tears if there are any serious faults. The main HT electrolytics really ought to be checked and re-formed. If not, you could ruin them and the PY82 rectifier valves. Even using a variac is no good because the rectifiers will only start to conduct with appreciable voltage to the heaters. You will have little control of the current unless a lamp limiter is used. A while back I restored a Bush TV53 which has the same chassis as the TV62. Here below is a link if you are interested.... https://www.radios-tv.co.uk/communit...s/bush-tv53-2/ __________________ Andrew

28th Apr 2021, 10:33 pm	#5
technotel Pentode Join Date: May 2018 Location: High Wycombe, Buckinghamshire, UK. Posts: 135	Re: Bush TV62 You guys are magical. I take all this advise with great excitement. Thank you all for these tips...Awesome. I will follow all line by line. And let you know how I get on. Terry

28th Apr 2021, 10:44 pm	#6
Duke_Nukem Octode Join Date: Jan 2003 Location: Birmingham, West Midlands, UK. Posts: 1,268	Re: Bush TV62 Pay particular attention to the wires under the power chassis. There's a number that run under a tag strip and on the TV62 I worked on the insulation was crumbling to dust and where they go through the chassis to the top side of the chassis they were close to shorting together. A major pain as to access the wires requires lifting the tag strip, which meant unsoldering a lot of bits. Ended up doing a mass cap and wire change, I was amazed it actually worked afterwards. I'm not a fan of using a variac; effectively you are under-running the valves, particularly the HT rectifiers (as mentioned by PYE 405) and they work hard enough as it is. Reform / check HT electrolytics, ensure there are no HT shorts, snip mains filter cap, check voltage taps, add a meter to monitor the HT rail. Then give it the beans, though to be honest I always change the grid cap coupling to the LOP bottle and change the boost cap. Regarding the LOP transformer, whilst I got lucky and mine has been fine if I had my time again I'd have run some DC through it to ensure it was nicely dried out first. TTFN, Jon

29th Apr 2021, 7:39 am	#7
Mr Hoover Hexode Join Date: Jan 2007 Location: Faro, Portugal Posts: 269	Re: Bush TV62 Check the condition of the long wires running very close to the cabinet foil screening to the above right of the line output can. They get gently cooked by the line output stage and the proximity of the foil can cause "interesting" intermittent effects.