UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Vintage Television and Video

Notices

Vintage Television and Video Vintage television and video equipment, programmes, VCRs etc.

Closed Thread
 
Thread Tools
Old 5th Jun 2022, 10:25 am   #41
Helder Crespo
Hexode
 
Helder Crespo's Avatar
 
Join Date: Sep 2019
Location: Crystal Palace, Bromley, London, UK.
Posts: 417
Default Re: Reviving a dead Bush (TV22!)

Quote:
Originally Posted by Heatercathodeshort View Post
These receivers were probably used daily from around 1950 to maybe 1960. The much more usable TUG24/TV24 tended to carry on a bit especially with the much older generation.
This daily switch on dried any moisture preventing LOPT breakdown.
They were then placed in damp sheds and lofts for 60 years resulting in the pitch, being hydroscopic became contaminated with damp.
Once dried out and used occasionally in a centrally heated home there should not be a problem with recontamination. There is no golden rule or cure. Do whatever you feel happy with. The main cause of breakdown today is a shorted primary to secondary winding, not the overwind. These transformers were very reliable in their day. The TV22 was well on it's way out when I entered the trade but I did service quite a number of TV/TUG24s and never encountered a duff Lopt. John.
Thanks John. I think I will try a similar approach with the LOPT in my newest TV22 Mk1. The first of my previous two LOPTs suffered a primary-secondary short (since rewound), although I can't say it has been thoroughly dried, and the second (from a scrap chassis in very poor condition) had its pitch dissolved in white spirit and was then fully varnished. This treatment has proved efficient, as the LOPT has worked every day for over 1 year now without issues. However, these two LOPTs underperform, not in terms of maximum EHT value (both deliver 9kV) but in terms of regulation. So I'm hoping that a basically untouched and thoroughly dried LOPT may have better performance, even though there is a risk of primary-secondary shorts anyway. The fact that my newest TV22 is totally free from corrosion is a good thing, as this invariably correlates to the set having been properly stored in a dry environment.
- Helder
Helder Crespo is offline  
Old 1st Jul 2022, 8:48 pm   #42
Lloyd 1985
Nonode
 
Lloyd 1985's Avatar
 
Join Date: Jun 2008
Location: Coningsby, Lincolnshire, UK.
Posts: 2,814
Default Re: Reviving a dead Bush (TV22!)

Time for an update! I have been making steady progress with the cleaning up of the chassis, and finally got chance to start putting it all back together. I pretty much stripped it as far as I dared, and cleaned the aluminium with foam cleaner and P400 sandpaper, which shifted the majority of the white crusty corrosion, the worst was behind the serial number plate! The lopty had to have the heater winding rewound as I managed to break off the little tagstrip because the EHT lead had gone rock hard, I reused the old wire, and only lost 1 turn off it. I covered it with thick heat shrink tubing, which I also used to replace the perished rubber that was used between the laminations and the lopty mounting brackets. All the waxy caps have been evicted, and all but 2 replaced, just the big hum filter and the mains filter remain. Electrolytics seem ok, but the 2uF ones are to be replaced with film caps when they arrive, resistors all seemed to be in tolerance, so none have been replaced.

Today I finally got the chassis mostly reassembled, just waiting for the 2 wooden side panels, I filled the woodworm holes and need to let that dry then give them a coat of satin black to spruce them up. Everything else is in place!

First power up was nerve wracking, it all seemed to come to life, but no picture or EHT, after a bit of head scratching I realised I’d forgotten to plug the scan coils in! With that done I tried again, this time EHT came up, along with a dim fuzzy and small raster! After some tweaking I had a good looking test card up on screen

The tube does have a partially shorted heater, the voltage only gets to 4.8V, some gentle tapping can restore it for a few seconds, but equally can make it worse, dropping it to 3.9V, I’ll leave well alone, even when the voltage drops the picture is still good, in fact there isn’t much difference between it sat at 4.8V to when it goes up to 6.3V! I did try rotating the tube a little, but it’s made no difference.

The set has been running for well over an hour now, picture is still good, sound is good too from the rebuilt speaker, the EHT is steady at 7.5KV, with the brightness set for a good picture, with it down to nothing the EHT is just under 8KV. The lopty is a bit warm, my laser thermometer says about 55 degrees C, that does bother me a little, but maybe it’s ok?

There are just a few finishing touches left, the speaker needs some felt, and the wooden bits need to go on, then it’s ready for the cabinet!

Regards
Lloyd
Attached Thumbnails
Click image for larger version

Name:	0C894596-6099-4FB6-9997-FAA52F89C715.jpg
Views:	114
Size:	90.8 KB
ID:	260218   Click image for larger version

Name:	1BDEFFA4-A94F-4543-8D3C-6B16B852ABE1.jpg
Views:	114
Size:	123.2 KB
ID:	260219   Click image for larger version

Name:	4ACBC7F1-EBFE-4F4F-B86B-ECCA3FC4F779.jpg
Views:	110
Size:	113.0 KB
ID:	260220   Click image for larger version

Name:	66C131C7-D7BA-4703-BC0A-226981A74CC1.jpg
Views:	111
Size:	122.5 KB
ID:	260221   Click image for larger version

Name:	3D3394A2-BE09-4285-9D51-917583A49B7D.jpg
Views:	113
Size:	129.8 KB
ID:	260222  

Lloyd 1985 is online now  
Old 1st Jul 2022, 8:55 pm   #43
Lloyd 1985
Nonode
 
Lloyd 1985's Avatar
 
Join Date: Jun 2008
Location: Coningsby, Lincolnshire, UK.
Posts: 2,814
Default Re: Reviving a dead Bush (TV22!)

More pictures!
Attached Thumbnails
Click image for larger version

Name:	F462E744-D13C-4CFD-823A-889491191C9B.jpg
Views:	113
Size:	86.4 KB
ID:	260226   Click image for larger version

Name:	916A2807-7A32-4CE4-87D3-7B3ED21B8D74.jpg
Views:	119
Size:	62.6 KB
ID:	260227   Click image for larger version

Name:	5A9E411E-3485-4051-B656-EC088730D9E8.jpg
Views:	115
Size:	115.1 KB
ID:	260228   Click image for larger version

Name:	CC5E203C-6979-49E0-8451-567F2EAA92B6.jpg
Views:	139
Size:	98.6 KB
ID:	260229  
Lloyd 1985 is online now  
Old 1st Jul 2022, 9:02 pm   #44
Helder Crespo
Hexode
 
Helder Crespo's Avatar
 
Join Date: Sep 2019
Location: Crystal Palace, Bromley, London, UK.
Posts: 417
Default Re: Reviving a dead Bush (TV22!)

Thanks Lloyd! The chassis looks great and the image too. You're really doing a great job in reviving this set. Does your image size change a lot with brightness? I'm curious to know how a dried but otherwise untouched LOPT behaves compared to one that has been stripped of pitch and varnished.
- Helder
Helder Crespo is offline  
Old 1st Jul 2022, 9:10 pm   #45
Lloyd 1985
Nonode
 
Lloyd 1985's Avatar
 
Join Date: Jun 2008
Location: Coningsby, Lincolnshire, UK.
Posts: 2,814
Default Re: Reviving a dead Bush (TV22!)

So far there hasn’t been much change in picture size vs brightness on the videos I was watching, there is a big difference when you whack it up full brightness, but with normal viewing it’s only a few mm change, the video I had going was a livestream concert from during lockdown, and there was a lot of flashing lights in that. EHT was fairly steady, just dropping down to 7KV from 7.5KV. After an hour running the EHT was still about the same as when I first measured it! I was impressed…!

Regards
Lloyd
Lloyd 1985 is online now  
Old 1st Jul 2022, 9:34 pm   #46
Helder Crespo
Hexode
 
Helder Crespo's Avatar
 
Join Date: Sep 2019
Location: Crystal Palace, Bromley, London, UK.
Posts: 417
Default Re: Reviving a dead Bush (TV22!)

That sounds really great Lloyd. Have you used any varnish or coating at all on your LOPT?
- Helder
Helder Crespo is offline  
Old 1st Jul 2022, 10:43 pm   #47
Lloyd 1985
Nonode
 
Lloyd 1985's Avatar
 
Join Date: Jun 2008
Location: Coningsby, Lincolnshire, UK.
Posts: 2,814
Default Re: Reviving a dead Bush (TV22!)

No, just the original pitch, the only bit I did change was the covering over the heater winding, as the original pitch there had to come off to repair that, and I replaced it with thick heat shrink.

Regards
Lloyd
Lloyd 1985 is online now  
Old 5th Jul 2022, 7:18 pm   #48
Lloyd 1985
Nonode
 
Lloyd 1985's Avatar
 
Join Date: Jun 2008
Location: Coningsby, Lincolnshire, UK.
Posts: 2,814
Default Re: Reviving a dead Bush (TV22!)

A bit more work, replaced the 2 x 2uF electrolytics with 2.2uF film caps, audiophoolery grade! They measure bang on the money, and the set seems happy with them. Also refurbished the 2 wooden panels, they had the dreaded worm, so they have been soaking in bug killer for a few weeks in a sealed bag, and I’ve filled the worm holes (sadly they didn’t lead to another dimension…) then sprayed them with Halfords satin black. I have also been and grabbed the RF deck that has a band 3 tuner add on, it looks in ok condition, not too much corrosion, there are no valves in the band 3 bit, anyone know what they should be? I’ll pinch the other valves from the sets original RF chassis. It’s totally untouched, all the original waxy snot gobs are still present, and nothing looks burnt or otherwise untoward!

Regards
Lloyd
Attached Thumbnails
Click image for larger version

Name:	C88F1152-BA8D-4E41-B0E0-2C4E2550D828.jpg
Views:	108
Size:	103.7 KB
ID:	260476   Click image for larger version

Name:	1D91D23A-C3CE-4072-A794-BC081F736B5A.jpg
Views:	107
Size:	98.0 KB
ID:	260477   Click image for larger version

Name:	C8A3616B-E8BD-45D0-9B5E-9776C3156BB3.jpg
Views:	113
Size:	59.8 KB
ID:	260478   Click image for larger version

Name:	A885958A-FC70-4414-A4CC-CDEFC90E16F7.jpg
Views:	114
Size:	80.6 KB
ID:	260479  
Lloyd 1985 is online now  
Old 5th Jul 2022, 7:22 pm   #49
stevehertz
Dekatron
 
stevehertz's Avatar
 
Join Date: Sep 2011
Location: Rugeley, Staffordshire, UK.
Posts: 8,809
Default Re: Reviving a dead Bush (TV22!)

Nice work Lloyd.
__________________
A digital radio is the latest thing, but a vintage wireless is forever..
stevehertz is offline  
Old 5th Jul 2022, 7:58 pm   #50
Lloyd 1985
Nonode
 
Lloyd 1985's Avatar
 
Join Date: Jun 2008
Location: Coningsby, Lincolnshire, UK.
Posts: 2,814
Default Re: Reviving a dead Bush (TV22!)

Cheers Steve

I also found that broken Ekco cabinet when I fetched the RF chassis! Just packing up a piece of it now.

Regards
Lloyd
Lloyd 1985 is online now  
Old 5th Jul 2022, 8:04 pm   #51
Heatercathodeshort
Dekatron
 
Heatercathodeshort's Avatar
 
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 9,145
Default Re: Reviving a dead Bush (TV22!)

A very nice result Lloyd. John.
Heatercathodeshort is offline  
Old 5th Jul 2022, 8:27 pm   #52
Lloyd 1985
Nonode
 
Lloyd 1985's Avatar
 
Join Date: Jun 2008
Location: Coningsby, Lincolnshire, UK.
Posts: 2,814
Default Re: Reviving a dead Bush (TV22!)

Cheers John

It’s getting there! I’m still surprised that I got it going at all!

I just did the line drive trimmer adjustment, which has increased the width a fair bit, I’ve not checked the EHT yet though.

Regards
Lloyd
Lloyd 1985 is online now  
Old 6th Jul 2022, 10:49 am   #53
Panrock
Nonode
 
Panrock's Avatar
 
Join Date: Feb 2005
Location: Worcestershire, UK.
Posts: 2,525
Default Re: Reviving a dead Bush (TV22!)

Good work.

Steve
__________________
https://www.radiocraft.co.uk
Panrock is online now  
Old 6th Jul 2022, 11:48 am   #54
Jac
Heptode
 
Jac's Avatar
 
Join Date: Jun 2006
Location: Eindhoven, Netherlands.
Posts: 640
Default Re: Reviving a dead Bush (TV22!)

Excellent work Lloyd!

Jac
Jac is offline  
Old 6th Jul 2022, 11:53 am   #55
greg_simons
Octode
 
greg_simons's Avatar
 
Join Date: Jul 2004
Location: Evesham, Worcestershire, UK.
Posts: 1,415
Default Re: Reviving a dead Bush (TV22!)

Super work there, time i got a '22" to annoy swmbo even more!, shame about the cat but perhaps in time a better one may surface.
Greg,
__________________
Picture, sound?, DOOR.
greg_simons is offline  
Old 12th Jul 2022, 11:38 pm   #56
Lloyd 1985
Nonode
 
Lloyd 1985's Avatar
 
Join Date: Jun 2008
Location: Coningsby, Lincolnshire, UK.
Posts: 2,814
Default Re: Reviving a dead Bush (TV22!)

It’s all coming together nicely! I have the other RF chassis, complete with band 3 converter, it’s not in bad condition, some light rusting in places, the string has snapped on the tuning, and there’s no valves. I had a dig through stores and found the 2 valves for the band 3 tuner, and the others can come off the original chassis.

Now for the really interesting bit, the cabinet! I dug out the unsuspecting victim, the very first ‘TV22’ I ever purchased, or so I thought until it arrived, and I found a Thorn inside it! As you can imagine, I was not best pleased at all, so the poor thing has spent most of its life stuffed in the back of a wardrobe. At least it worked I suppose, although it doesn’t work now, just a blank raster with faint hiss on the sound.

The cabinet isn’t the best, it’s cracked just below the screen, there’s a hole drilled above the screen for a magnifier, and it’s a bit dull. Someone’s painted the rubber mask gold in the past too, but I kind of like it! I will get round to doing a proper repair to the cabinet eventually.

With the imposter extracted, I fitted the cabinet onto the newly revived chassis, I had to make some adjustments to get things to line up, the hold controls still don’t quite line up, despite a couple of attempts to tweak them. The volume knob put up one hell of a fight! I couldn’t fit it with the screw in place, so spent ages trying to get the screw in down the slot, but kept dropping it, then when it did go in, it stripped the threads on the screw, so I ended up having to file it down. It would have helped if the volume pot was original, as the one fitted doesn’t have a flat on the shaft.

with that out of the way, I could then turn my attention to setting up the picture. I spent a fair bit of time squaring it up, messing with the ion trap and focus magnets until I was happy with it. I left it to run for a few hours to see how it went, and so far it seems to be ok! I’d forgotten just how much heat comes from them, but it still seemed happy enough.

There are 2 things I’d like to address, one being the lack of fly back blanking, and the other being the rubbish interlacing. It doesn’t seem to matter where the hold control is, it either has what looks like line pairing, or just no interlace. I did try something I saw on another thread, where R11 (Bush manual), 100K can be reduced in value to 10K, but that didn’t make any difference to it.

A couple of other bits I forgot to mention, I have found some felt, which I have used to make a new dust cover for the speaker, and also stuck some in the wooden feet. Oh, and the tube has decided to play nice! Heater now sits at 6.5V, so a little over run, and I have got it in the 250V setting.

Regards
Lloyd
Attached Thumbnails
Click image for larger version

Name:	33B5188A-80D6-4AD2-A340-FCA4D3FE0887.jpg
Views:	90
Size:	197.0 KB
ID:	260841   Click image for larger version

Name:	052450C2-1A9B-44F3-8CAE-9FB3351F3208.jpg
Views:	91
Size:	188.4 KB
ID:	260842   Click image for larger version

Name:	BFC7A94C-1DC2-43C7-9125-FEFD136D4891.jpg
Views:	93
Size:	152.5 KB
ID:	260843   Click image for larger version

Name:	6E7BAC20-8F4F-4993-8CC0-BBAAECC21FFF.jpg
Views:	90
Size:	108.3 KB
ID:	260844   Click image for larger version

Name:	A5049273-F531-4E66-AD6F-89AC1D5BE224.jpg
Views:	98
Size:	96.5 KB
ID:	260845  

Lloyd 1985 is online now  
Old 13th Jul 2022, 11:40 am   #57
Tazman1966
Nonode
 
Tazman1966's Avatar
 
Join Date: May 2006
Location: St Albans, Herts, UK.
Posts: 2,193
Default Re: Reviving a dead Bush (TV22!)

Quote:
Originally Posted by Lloyd 1985 View Post
...It’s all coming together nicely!...
It certainly is! The TV22 and its ilk is not something that I've ever had but this may well change in the future.
__________________
All the very best,
Tas
Tazman1966 is offline  
Old 13th Jul 2022, 12:18 pm   #58
peter_scott
Dekatron
 
peter_scott's Avatar
 
Join Date: May 2003
Location: Edinburgh, UK.
Posts: 3,273
Default Re: Reviving a dead Bush (TV22!)

Quote:
Originally Posted by Lloyd 1985 View Post
The volume knob put up one hell of a fight! I couldn’t fit it with the screw in place, so spent ages trying to get the screw in down the slot, but kept dropping it, then when it did go in, it stripped the threads on the screw, so I ended up having to file it down. It would have helped if the volume pot was original, as the one fitted doesn’t have a flat on the shaft.

Regards
Lloyd
I don't know if this is relevant but I find that the volume and brightness knobs need to be in their cabinet holes before the chassis is pushed in to meet them.

Because the knob fixing screws have heads on them I need to hook them through the holes which isn't possible when the pot shafts are in place.

Peter
peter_scott is offline  
Old 13th Jul 2022, 2:07 pm   #59
Helder Crespo
Hexode
 
Helder Crespo's Avatar
 
Join Date: Sep 2019
Location: Crystal Palace, Bromley, London, UK.
Posts: 417
Default Re: Reviving a dead Bush (TV22!)

Quote:
Originally Posted by peter_scott View Post
Quote:
Originally Posted by Lloyd 1985 View Post
The volume knob put up one hell of a fight! I couldn’t fit it with the screw in place, so spent ages trying to get the screw in down the slot, but kept dropping it, then when it did go in, it stripped the threads on the screw, so I ended up having to file it down. It would have helped if the volume pot was original, as the one fitted doesn’t have a flat on the shaft.

Regards
Lloyd
I don't know if this is relevant but I find that the volume and brightness knobs need to be in their cabinet holes before the chassis is pushed in to meet them.

Because the knob fixing screws have heads on them I need to hook them through the holes which isn't possible when the pot shafts are in place.

Peter
I totally agree with Peter. The knobs have to be in their holes - screw in place but not tight so that the shaft can slide in - and must be carefully aligned and inserted into the shafts as the cabinet is pushed in. This is the way to do it even for the original pots/shafts. Trying to insert the screws afterwards is a nightmare and can easily crack the bakelite.
- Helder
Helder Crespo is offline  
Old 13th Jul 2022, 3:59 pm   #60
Lloyd 1985
Nonode
 
Lloyd 1985's Avatar
 
Join Date: Jun 2008
Location: Coningsby, Lincolnshire, UK.
Posts: 2,814
Default Re: Reviving a dead Bush (TV22!)

Cheers guys! Taz, go for it! So long as you get a good set that’s been stored well it should be ok, don’t know why I keep going for these basket cases…

Looking at it now, putting the knobs in place before fully inserting the chassis would have been sensible! I did think maybe I should have done that when I was swearing at the screw for dropping on the floor for the millionth time, at least I’ll hopefully remember to do that when I have to take it out again to repair that crack.

I have also realised the back cover is junk, the top bit where the screws hold it on has disintegrated, so I’ll have to do something about that as well.

Regards
Lloyd
Lloyd 1985 is online now  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 2:18 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.