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Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
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13th Jul 2022, 8:13 pm | #1 |
Pentode
Join Date: Jun 2008
Location: Christchurch, Dorset, UK.
Posts: 237
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Philco 471 Problems
I recently acquired a 471 with a very poor condition chassis. Rather foolishly I just stripped it down to bare chassis in order to de-rust & paint it bewfore rebuilding. I say foolishly because I didn't make any notes of the connections to the wavechange switch, coils or IF's. I thought I could just rebuild it from the circuit diagram, but firstly the aerial coil had several o/c connections (not the windings but the lead outs were corroded), and more of an issue, it's taken an eternity to work out the connections. Using the resistance readings I have now done that (I hope!), but I'm puzzled about the very complex wavechange switching. Using the ERT data sheet views of the rear of the wafers it appears that the fully anticlockwise position is Short wave - can someone please confirm that. Better still, can someone tell me the waveband order from anticlock to clockwise.
Picture of the very partly rebuilt chassis and what I believe are the aerial coil connections. Last edited by Colin Boggis; 13th Jul 2022 at 8:17 pm. Reason: spelling |
13th Jul 2022, 8:24 pm | #2 |
Heptode
Join Date: Sep 2010
Location: Hythe, Hampshire, UK.
Posts: 626
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Re: Philco 471 Problems
Trader sheet 746 gives some explicit information on the switches and states the fully anti-clockwise position is LW then rotate clockwise for MW, SW and finally Gram. Good luck with getting it sorted.
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14th Jul 2022, 9:21 am | #3 |
Octode
Join Date: Dec 2019
Location: Owston Ferry, North Lincolnshire, UK.
Posts: 1,689
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Re: Philco 471 Problems
Both trader sheets and the manufactureres service manual are available as downloads from the above link.
Dave
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Quote "All is hyperthetical, until it isn't!" (President Laura Roslin, Battlestar Galactica) |
14th Jul 2022, 11:20 am | #4 |
Pentode
Join Date: Jun 2008
Location: Christchurch, Dorset, UK.
Posts: 237
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Re: Philco 471 Problems
PJC58-Hythe - I do have trader sheet 746 and the earlier 190. I had missed the significance of the switch details, not realising (I should read all the text!!) that the wavebands were in order or that they start from LW at full anti-clock. It just confirms my foolishness (another senior moment perhaps!)
G6ONEDave - when you say manufacturer's data is available on the above link, are you referring to the link in the response from PJC58-Hythe? |
14th Jul 2022, 12:03 pm | #5 |
Dekatron
Join Date: Aug 2013
Location: Wigan, Greater Manchester, UK.
Posts: 9,427
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Re: Philco 471 Problems
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Frank |
14th Jul 2022, 7:45 pm | #6 |
Pentode
Join Date: Jun 2008
Location: Christchurch, Dorset, UK.
Posts: 237
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Re: Philco 471 Problems
The manufacturers data sheet is the best! Very clear picture of underside which will be a great help/ Thanks Nuvistor.
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24th Jul 2022, 11:21 am | #7 |
Pentode
Join Date: Jun 2008
Location: Christchurch, Dorset, UK.
Posts: 237
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Re: Philco 471 Problems
I have now rebuilt the chassis, sorting out the switch connections from the various service sheets (very confusing as they use different reference numbers & views of the switch!). The aerial coil had problems, O/C longwave tap & shortwave coupling coils - I managed to repair the LW connection and rewound the SW coil. I haven't accurately followed the original component layout as it didn't seem entirely logical. I noticed later that I'd fitted IF2 into the chassis 90 degrees out, but as it's of no consequence and they're hard to get out, I'm leaving it as is. I was very pleased to find all 4 valves are good - I was concerned the PenDD61 might be duff, but it's fine. I've also modified the top cut tone control from a switch to a potentiometer with push-pull switch as I'll use this to activate a Bluetooth module which is my next move. I've also got the cabinet to strip and re-stain (except the front which will be OK with minor touching-in). I'm surprised at the volume this radio gives from just 3 valves - it's loud!
Last edited by Colin Boggis; 24th Jul 2022 at 11:23 am. Reason: Grammar! |
24th Jul 2022, 4:38 pm | #8 |
Octode
Join Date: Feb 2007
Location: Harrow, London, UK.
Posts: 1,483
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Re: Philco 471 Problems
Colin
Had you thought about writing up your experience for the BVWS magazine? Photo's of the original condition to where you are now would be very rewarding for the reader. The chassis looks better than new and your journey to getting the AE coil, wavechange switch and IF's working would be both instructive and, dare I say, educational. Chris Last edited by simpsons; 24th Jul 2022 at 4:40 pm. Reason: Missing IF work |
24th Jul 2022, 7:27 pm | #9 |
Pentode
Join Date: Jun 2008
Location: Christchurch, Dorset, UK.
Posts: 237
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Re: Philco 471 Problems
Unfortunately I didn't take any pictures of the chassis in it's original condition. Also I'm no longer a member of the BVWS so I don't think I can write articles for them.
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14th Aug 2022, 8:24 pm | #10 |
Pentode
Join Date: Jun 2008
Location: Christchurch, Dorset, UK.
Posts: 237
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Re: Philco 471 Problems
Bluetooth unit now added to the radio. activated by a pull switch on a replacement tone control and by selecting "Gram". Had to add amplifier to the KRC-86B as not enough drive without it. Used simple LM386 circuit. Works very well. Blue status LED fitted against the pilot bulb holder. Shows up nicely ( although not obvious in photo as brightness of bulb causes glare on camera)
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15th Aug 2022, 10:05 am | #11 |
Dekatron
Join Date: Feb 2009
Location: Chesterfield, Derbyshire, UK.
Posts: 3,737
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Re: Philco 471 Problems
Well done in getting it sorted Colin, very nice, its good to see the dial is in such good condition. Mick.
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