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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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5th Feb 2017, 11:52 am | #1 |
Triode
Join Date: Jan 2017
Location: Hampshire, UK.
Posts: 24
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Philips 462A
Hi,
I recently posted a question on this forum about the HT voltage of my Philips 462A that I have been restoring. The set was originally given to me by my grandmother. Although it's taken 25 years of very intermittent activity to get this far, I have now decided the set is done. In total it needed: General filth removal New electrolytics New volume control New AZ31 rectifier valve, replacing incorrect U50 Replacement of output valve grid capacitor New speaker cloth Fettling of waveband switch T cut and polish of case, repainting of 'go-faster' stripes It now works very well. The station alignment against the dial is spot on on MW, but slightly out on LW (R4 peaks at an indicated 1495 m, not 1515). I've not touched the IF or RF alignment out of fear I could improve it backwards. MW works well on 3 or 4 metres of wire as an antenna, but I'm using about 10 m so that R4 LW is at good strength. The LW section doesn't like CFL light bulbs! One of the best features of the set is that the glass dial is undamaged with perfect printing. Its worst feature is a crack in the case by the tone control, but you only see this if you go looking for it. Sometime I need to find new screws for the base and back panels; these screws were missing when I was given the set and a certain amount of somebody's Meccano set was apparent. The HT voltage with the new rectifier valve is 40 V or so lower than the Trader sheet values. Forum advice was that this could be because the Nos AZ 31 might be a bit below par. Having looked more carefully I have another theory. I now think the set has been repaired long ago with a non-standard mains transformer. The transformer has a fuse on it not shown on the Trader Sheet diagram. Also, the voltage selector panel has been replaced by a Radio Spares item, nothing like the item seen in other examples of the set (see photos). The wiring for the transformer and voltage selector panel seems in better condition than some of the other wiring in the set, but still looks old. So I suspect the mains transformer is a generic replacement fitted when the set was still in every day use but which has a different turns ratio for the HT. With hindsight, I knew this at the start but had never put two and two together. Anyway, the repair was done to a high standard and the set works fine. It's part of its history so I'm going to leave it. Philips radios seem to have a reputation for complexity on this forum. I think I got lucky with this one as it only needed a few obvious component changes to get it going again. Ed |
5th Feb 2017, 1:45 pm | #2 |
Dekatron
Join Date: Aug 2007
Location: W.Butterwick, near Doncaster UK.
Posts: 8,932
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Re: Philips 462A
Well you got there well done and that is all that matters. Try polishing the cabinet with Chas Millers Bake O Bryte.
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G8JET BVWS Archivist and Member V.M.A.R.S |
5th Feb 2017, 9:47 pm | #3 |
Dekatron
Join Date: Feb 2009
Location: Chesterfield, Derbyshire, UK.
Posts: 3,761
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Re: Philips 462A
Well done Ed !
there not the easiest of sets to work on ,I have one in my collection they preform very well.Mick. |
6th Feb 2017, 10:19 pm | #4 |
Hexode
Join Date: Jun 2009
Location: Cheshire, UK.
Posts: 363
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Re: Philips 462A
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12th Feb 2017, 7:58 pm | #5 |
Dekatron
Join Date: Apr 2005
Location: Bewdley, Worcestershire, UK.
Posts: 4,748
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Re: Philips 462A
"Bake-O-Bryte" is a very good product, but it appears to be a repackaged version of the original Greygate 'Paste Polishing No 5' which is half the price.
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Phil Optimist [n]: One who is not in possession of the full facts |
26th Mar 2017, 9:54 pm | #6 |
Dekatron
Join Date: Oct 2003
Location: Southport Lancashire, UK.
Posts: 3,233
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Re: Philips 462A
I did one of these a few months ago. I found the way the tuning capacitor was attached to be somewhat unusual. It has long springy wires coming from the chassis to screws on the capacitor frame. They were all disconnected on mine leaving the cap free to move but when I re-fastened them all the arrangement actually works a lot better than it seems it will.
I never managed to get much out of the foil aerial, though.
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Paul |
27th Mar 2017, 12:26 am | #7 |
Dekatron
Join Date: Nov 2011
Location: Surrey, UK.
Posts: 4,395
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Re: Philips 462A
Well done on persevering and completing, we've probably all succumbed to "back burner syndrome" with various projects. I like distinctive sets like this, much as I like the HMV1121 with its "glass venetian blind" speaker grill presentation- though both probably suffered a fair amount of attrition in their time!
Forgive me if I'm stating the obvious or teaching anyone to suck eggs, but is it possible that this replacement transformer has a 5V, rather than 4V rectifier winding, hence the originally found U50? At least, it would only take an appropriate small wire-wound heater dropper resistor to suit the AZ31 if so. |
27th Mar 2017, 12:27 pm | #8 |
Triode
Join Date: Jan 2017
Location: Hampshire, UK.
Posts: 24
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Re: Philips 462A
I did measure the heater volts on the AZ31 - I got a reading of 3.8 VAC on my £10 cheapo DVM - so I think things are OK. I think the DVM is reasonably accurate as it gives a sensible reading when measuring the mains voltage; on the other hand its most sensitive AC voltage scale is 200V FSD so it probably wasn't the best device to use...
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