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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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Old 13th Jun 2021, 2:16 pm   #1
Beardyman
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Default Wartime Civilian Receiver (U21, Philco)

I thought I'd write up the Wartime Civilian Receiver recently restored before the next set (Philips 131U) occupies the bench!
It arrived in a bit of a sorry state, in it's past someone had given it a liberal coating (complete with runs & drips) of very dark varnish which, for the most part, was flaking off. The top of the case had separated from the rest of the set & the corner braces were floating around inside. The valve line up as received was as follows:
V1 = CCH35, V2 = W147, V3 = BVA267, V4 = IW4/350
It had certainly had a change or two since being made. The CCH35 is essentially an ECH35 with a 7V heater intended for series connection as far as I can see. As most of the shielding paint had fallen off I purchased an ECH35 (NOS) as instability could have made it's presence felt. The OT was not original either, I eventually found out it was of the universal type supplied by RS back in the day, not much seems to have changed then!
All the smoothing caps had been replaced by the ubiquitous grey RS capacitors so popular in the 70's, whoever had done it did a really good job as they looked perfectly at home & they all reformed well. This set has the identifier "U21" stamped clearly on the back of the chassis, according to the trader sheet it was made by Philco. After searching the internet for more information (there's plenty out there!) it became apparent that the tuning scale is one of the key factors in dating these sets, mine was 1944, although how accurate that may be is open to conjecture. It's good enough for me & it fits the criteria. Considering the scale isn't protected by glass or plastic it was in remarkably good condition, just a wipe over with a damp cloth was all it needed. The chassis needed a good dusting & general clean up. Once done it didn't look half bad. The method of construction using a tag board is a positive joy. The cathode bias resistor for the BVA267 was cracked wide open indicating it had had a substantial overload at some point which tied in with the non-original OT. The bypass capacitor was defunct but I re-stuffed that one as a modern tiny part just wouldn't have looked right. Several others had drifted way past their value. All the wax capacitors were checked, a few would have made good resistors! The moulded mica caps all read good so were left alone. The only other concern I had was the Westector WX6 copper oxide diode. It "looked" ok which means nothing! As these are difficult to test I left it in just to see what happened, others on the forum had replaced this part with a germanium diode so it wasn't a show stopper if it didn't work.
I managed to get the speaker cloth off in one piece & gave it a gentle bath in mild soapy water. It was left overnight, either it would still be in one piece or not. Needless to say the water was filthy, a gentle rinse & once dried out the cloth had a goldish hue to it, quite nice.
The speaker was in very good shape apart from all the paint had fallen off or was in the process of doing so.
The mains transformer was in good shape too, it looks a bit on the big side for such a small set but the insulation was good & all the windings checked out ok. The mains switch, however, had less than 5M to it's metalwork, for the sake of safety & peace of mind it was changed out with a very similar modern one, whilst I was there I fitted a fuse as well & earthed the chassis. Some of the cotton covered wiring under the chassis was fairly rotten & crumbling, this was replaced with PTFE wire. The transformer wiring had been re-worked some years ago with PVC covered wire & to my eye just didn't "fit", there was nothing wrong from a technical viewpoint. I endeavoured to imitate the woven look by using nylon braided tubing with PTFE wire inside. Running it up on the variac without valves I was glad to see all the voltages were where they should be & about the right levels. I left it like this for about an hour to make sure the transformer had no hidden surprises, barely warm to the touch, all good. Valves in, about 3 yards of aerial attached, pantry TX on, power on! After about 30-40 seconds, nothing, not even hash. Oh dear, then tuned the set to around where the pantry TX is & lo! Sound came forth, obviously the Westector was working. It also picked up the few remaining MW stations round my way on just that short indoor wire. I decided to swap out the CCH35 for the NOS ECH35, a slight difference in sensitivity but not much, I left the ECH35 in. All in all a nice sounding set, easy to work on & robust construction.
The case was a different matter!
The old varnish was scraped off as I wasn't sure if there was a label on the top or not, as it turned out there wasn't further confirming the fact that others had been there before me. You know when something is so dried out it feels almost desiccated? That's exactly how the wood felt on this set, three coats of Danish oil inside & out then it started to look a lot better. I noticed on the back edge of the top was stamped a number, 4735. This number was also pencilled on the label on the backboard. I have no idea as to what it means! Using a couple of picture frame type clamps the top was re-glued & the bracing pieces re-attached. Speaker cloth re-glued/stretched gingerly & left to set overnight. Speaker re-installed & hooked up, one thing left to do was the tuning cord which had given up the struggle whilst I was seeing to the case. I heard a dull twang, looked over at the chassis & saw the cord hanging forlornly off. Luckily it's a simple run on these sets. With that sorted it was time to put the chassis back, add the control knobs, pop the back on & it was done. They are fascinating little sets (I always imagined them to be bigger for some reason) & are most certainly of their time. The fact the government of the period managed to get all those manufacturers to work together, more or less, is nothing short of a miracle. Now, on with the Philips 131U with it's multi-open circuit mains dropper....
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Old 13th Jun 2021, 5:57 pm   #2
HamishBoxer
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Default Re: Wartime Civilian Receiver (U21, Philco)

Very nice job.
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