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Success Stories If you have successfully repaired or restored a piece of equipment, why not write up what you did and post details here. Particularly if it was interesting, unusual or challenging. PLEASE DO NOT POST REQUESTS FOR HELP HERE! |
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30th Jul 2018, 1:45 pm | #1 |
Triode
Join Date: Jul 2018
Location: Oxfordshire, UK.
Posts: 34
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1930s unknown 3 valve Mullard battery receiver
This was my first go at vintage radio restoration. It came to me as a working chassis in woodworm damaged cabinet, missing speaker, audio transformer or power. I had the seller’s word that the radio was working. Lacking any service manual, the seller had to guess at some of the supply voltages, and went with 120v, 80v, 2v and -4.5v.
After separating cabinet from chassis, I got to work on the woodworm holes and had a go at filling and refinishing. I also had a go at washing the original speaker cloth, using several dunks in warm ‘oxi action’ stain remover. I’ve included a picture of the cabinet before and the speaker cloth in the wash. I didn’t really do anything special with the refinishing, other than, scrubbed away all the existing varnish down to bare wood, filled the holes with wood filler. Rubbed down with a 120 grit paper. That was followed by a few cycles of dark wood varnish, wet and dry rub down at 800 grit. On the electronic side, I was really struggling to get the chassis working. I would get a lot of regen oscillation and not much more than Radio 4 LW. This has been documented at:- https://www.vintage-radio.net/forum/...92#post1056692 In the end, it turned out that I had a very noisy power supply unit producing the 2v supply for the heaters. Once I had come up with a good clean supply, the radio would receive a good number of channels on MW and LW. BoxDoctor supplied me with a great audio transformer that you can see fitted, and I wired that up to a cheap 8” speaker. It seemed to be the best thing I could find to go in there and sounds quite good in that cabinet. On the power supply side, for now, I’ve stuck with batteries, and stuffed everything into a project box to make it modular. Six connections on a terminal block for HT- HT+ HT2 GB LT+ LT- So far I’m quite pleased with it and can’t wait to start on my next one (a McMichael 471 set) If anyone recognises this 1930s set and can identify it, please let me know. Thanks Tam |
30th Jul 2018, 4:40 pm | #2 |
Dekatron
Join Date: Aug 2007
Location: W.Butterwick, near Doncaster UK.
Posts: 8,935
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Re: 1930s unknown 3 valve Mullard battery receiver
Wish I knew the make and model as it is exactly like mine.No,I have no data sheet on it or certainly not that I am aware of at this point.Some one must know the make?
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G8JET BVWS Archivist and Member V.M.A.R.S |
30th Jul 2018, 5:56 pm | #3 |
Moderator
Join Date: Dec 2010
Location: Exeter, Devon and Poole, Dorset UK.
Posts: 6,878
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Re: 1930s unknown 3 valve Mullard battery receiver
I never worked out the maker and I had the set for at least 12 years.
I sold it when I lost store 4 (the garage) along with 20 other sets Mine definitetly originally had a moving iron speaker I know because I removed it to fit into one of my early Cossor sets. Pretty certain not Mullard or Philips, but a small manufacturer possibly assisted by Mullard to use their valves. The Studs look similar to a couple of Goodmans Speakers I have or had won't be sure till everything comes out of storage. Not at all sure Goodmans made whole sets at this time circa 33? Cheers Mike T
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Invisible airwaves crackle with life or at least they used to Mike T BVWS member. www.cossor.co.uk |
31st Jul 2018, 4:55 pm | #4 |
Heptode
Join Date: Apr 2010
Location: West Midlands, UK.
Posts: 663
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Re: 1930s unknown 3 valve Mullard battery receiver
Possibly J.G.Graves, their sets usually had only a paper label which could fall off.
Mike. |