24th Jan 2013, 8:57 pm | #21 |
Retired Dormant Member
Join Date: May 2011
Location: Sutton Coldfield, West Midlands, Uk.
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Re: My Bush tv43 restoration
I look forward to news on this.
Re modulators: http://www.thevalvepage.com/projects...at/modulat.htm gives a design that works. I did toy with the idea of making a printed circuit if there is not one out there already. The MC1496 IC is still available. ...But, as others have said, the Aurora is the real way to go! John |
25th Jan 2013, 4:33 am | #22 |
Hexode
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Re: My Bush tv43 restoration
This is my old bush tv at the railway station.
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25th Jan 2013, 5:13 am | #23 | |
Hexode
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Re: My Bush tv43 restoration
Quote:
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25th Jan 2013, 6:39 am | #24 |
Hexode
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Re: My Bush tv43 restoration
I found that the wire going to the contrast pot was rubber insulated and badly perished, I was reading about "Restoring a 1951 BUSH TV22 Television" http://www.radiocraft.co.uk/906.htm so I tryed tried it and maneged managed to pull the badly perished rubber inner cables out and replace with moden PVC cable, I tied the ends up with self-amalgamating rubber tape, I love that stuff.
tonight Tonight I desided decided to open the contrast pot and see how bad it is, I found the wiper badly corroded and the end of the track damaged and the brass wiper ring was also corroded so I cleaned the wiper ring carefully with a bit of brillo Brillo pad, I cleaned the track with cotten cotton wool buds and contact cleaner, I cleaned the wiper with a bit of brillo Brillo pad and thern then cotten wool buds and contact cleaner. where Where the track was damaged I would could see the end of the brass contact, I scraped it clean, then cleaned it with isopropyl and filled the hole with wire glue, the pot also had a pach of bad rust inside, I used a bit of brillo Brillo pad in it, dryed dried it and panted the pots pot's case inside and out with wood varnish, when it was dry I reassembled it and tested it, its it's labled labelled 1Mohm lin but its it's 1.125Mohm thats ok OK, I also tested dvm DVM and with my avo AVO multiminor mk4 that terned turned out to be broken was very fiddly and took ages to fix. it It had a broken controll control and burnt out wire in board resister resistor and track resister resistor, I will have to do some more work on it some time. After after all that work I have the pot working, and ready to be used |
25th Jan 2013, 9:25 am | #25 |
Octode
Join Date: Jan 2009
Location: Falmouth, Cornwall, UK.
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Re: My Bush tv43 restoration
Have you powered up the set yet, you need to establish if the tube has any life in it really before the time effort and money?
Whilst we hear of sucess stories most of the time on the forum, there are a fair percentage of sets that are beyond immediate repair/restoration either because of the tube being flat or a transformer failure or similar. First light is exactly that, getting light on the screen to prove it. It's quite a fun process waking them up, measuring, smelling, watching,____standing back I dont wish to sound negative though, you're doing a great job so far. Steve |
25th Jan 2013, 10:04 am | #26 | |
Hexode
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Re: My Bush tv43 restoration
Quote:
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25th Jan 2013, 10:18 am | #27 | |
Hexode
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Re: My Bush tv43 restoration
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Sso far I have lost count of the fails that I have fixed that could have damaged the tv TV, and a few months a go I had a sprise surprise when a filter in my 1980 commputer a commodoreCommodore 8032 exploded and filled my flat with bitter evil smoke |
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25th Jan 2013, 10:30 am | #28 |
Hexode
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Re: My Bush tv43 restoration
Wwhat type of diode is this? Iit is only listed as CD1?
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25th Jan 2013, 10:34 am | #29 |
Hexode
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Re: My Bush tv43 restoration
Mmain RF board, and this is after cleaning!
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25th Jan 2013, 10:41 am | #30 |
Dekatron
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
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Re: My Bush tv43 restoration
Yes, certainly obtain first light ASAP. The TV43 can be a beast to work on due to complicated chassis removal and tag board construction. Many mistakes can be made if you tackle all the problems in one go. Follow the service manual. Watch the cleaning. You may break things.
The MW36-24/44 tube often suffers from a partially shorted heater. [See other recent threads.] On the good side the remaining TV43's including the transformers appear to have survived well. I think I would have needed a disguise while pushing that sack barrow at the station. It's a wonder it was not seized and safely disposed of by the railway superintendent. Mind you my perambulator filled with TV receivers being pushed across the Merton Park level crossing back in 1960 comes a close second.. Good luck with it. Regards, John. |
25th Jan 2013, 10:46 am | #31 |
Octode
Join Date: Jan 2009
Location: Falmouth, Cornwall, UK.
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Re: My Bush tv43 restoration
Think you will find its a germanium vision detctor diode.
Steve |
25th Jan 2013, 10:48 am | #32 |
Hexode
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Re: My Bush tv43 restoration
I like the yellow capacitors as they are rated at 630v that at least 130v over the old wax capacitors, thay have long leads and anyone can tell they are new, I have been fitting a lot of them.
I tryed to pull the rubber wires out of the cloth sleeve so I could replace with PVC, but the old cable disintegrated, so I have used modern reproduction cloth coverd flex that is a good match to the old, I love that self amalgamating rubber tape. The cooked looking resistors are fine! Last edited by audion_1908; 25th Jan 2013 at 10:52 am. Reason: missing t |
25th Jan 2013, 11:05 am | #33 |
Hexode
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Re: My Bush tv43 restoration
I accidentally burnt the sleeving to had to replace it, I have cleaned the switches, the contacts where black!
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25th Jan 2013, 11:19 am | #34 |
Hexode
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Re: My Bush tv43 restoration
But what type would be a good replacement? or is it not to too fussy?
Last edited by audion_1908; 25th Jan 2013 at 11:33 am. Reason: Too meny BB's |
25th Jan 2013, 11:32 am | #35 | |
Hexode
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Re: My Bush tv43 restoration
Quote:
but I have found a diffrent one at http://www.radiomuseum.org/r/bush_tv43tv_4.html you have to log in to get it, I will see if my mystery diode is in there! and I have moved much more strange things |
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25th Jan 2013, 12:18 pm | #36 | |
Hexode
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Re: My Bush tv43 restoration
Quote:
the other Service manual from had the info http://www.radiomuseum.org/r/bush_tv43tv_4.html lists "In 1953 two types were produced distinguished by the conductivity of the germanium used: OA70 using higher conductivity germanium designed as a video detector OA50, OA51, OA53, OA55, OA56 and OA61 selected and graded from production" https://sites.google.com/site/transi...turers/philips they seem to be selling for £4 with postage for a black OA70? I will have to look up OA70 Equivalents Last edited by audion_1908; 25th Jan 2013 at 12:34 pm. |
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25th Jan 2013, 12:46 pm | #37 |
Retired Dormant Member
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Re: My Bush tv43 restoration
Hi there Audion 1908
The coils in the modulator can certainly be replced by similar ones. You will have to take turns off the windings of the IFT's to get them on to 45MHz. I used iron dust toroids in mine. If you can't get the integrated circuits, let me know. I have a couple in my box. I will be writing up the restoration project on the TV62 because I have promised to give a talk to Sutton Coldfield Radio Society in a few weeks' time. The set is working really well with a modest amount of boost to the heater. It still does have a partially shorted heater but not by half. Regarding the TV36C (17" not 23" as I said), The seller says he would like to see it restored - not broken up for parts. I am arranging to collect it next week and will decide then how to proceed. John |
25th Jan 2013, 1:40 pm | #38 |
Hexode
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Re: My Bush tv43 restoration
I dont know a lot about iron dust toroids exept there are a lot of diffrent types and sizes!
it is good to hear that the TV62 is going well, and hope the talk goes well, I was asked years ago to do a talk on my diy carbon resisters and wax capacitors, I did not do the talk in the end. and I have found wood plasticizer very usefall of badly rotten wood you may need some for the TV36C, good luck with getting the TV36C fully working thanks but I can get the integrated circuits, I have only done a quick look but £2.50 each on ebay I would love to read about you restoration project on the TV62 |
25th Jan 2013, 1:46 pm | #39 |
Dekatron
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Re: My Bush tv43 restoration
OA90 or OA91 should be ok.
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25th Jan 2013, 2:12 pm | #40 |
Hexode
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Re: My Bush tv43 restoration
This is why I have not tested the electrolytic capacitors, I have just replaced all of them, if I can I am leaving the dead electrolytic capacitors in the tv, just disconected, some future restorer may want to stuff them! and the new electrolytic capacitors may only be good for 20 or 30 years max!!
I found one Hunts capacitor, and two of the formerly red ceramic capacitors have got completely burnet, I have replaced them with 630v orange drop capacitors, I dont know if the old capacitors have damaged anything, they where used for heater decoupling so I may have a few open circuit heaters in the chain? should I worry about the other red ceramic capacitors as a lot have crackes where the wires enter, could damp have crept in? Last edited by audion_1908; 25th Jan 2013 at 2:17 pm. |