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4th Oct 2019, 6:12 pm
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#1 |
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Octode
Join Date: Jun 2005
Location: Sheffield, South Yorkshire, UK.
Posts: 1,227
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Murphy U472
I have just started looking at this .I will need a pair of 50 UF electrolytics . What/ where should I get them. Is 450v dc adequate 105C ?
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4th Oct 2019, 6:31 pm
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#2 |
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Dekatron
Join Date: Aug 2013
Location: Wigan, Greater Manchester, UK.
Posts: 9,431
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Re: Murphy u472
450 Vdc is fine, These are 500V D.C. but anything over 350vdc would be fine.
https://www.cricklewoodelectronics.c...Capacitor.html There are other suppliers, check this post . https://www.vintage-radio.net/forum/...d.php?t=160219
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Frank |
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5th Oct 2019, 1:19 pm
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#3 |
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Octode
Join Date: Jun 2005
Location: Sheffield, South Yorkshire, UK.
Posts: 1,227
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Re: Murphy U472
Can anyone sell me two?
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5th Oct 2019, 7:49 pm
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#4 |
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Dekatron
Join Date: Aug 2013
Location: Wigan, Greater Manchester, UK.
Posts: 9,431
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Re: Murphy U472
If it’s to replace c63 and c64 the one from cricklewood is a dual 50+50 500 vdc.
Are you looking for two to stuff the original can?
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Frank |
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7th Oct 2019, 11:03 pm
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#5 |
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Dekatron
Join Date: Sep 2005
Location: Seaford, East Sussex, UK.
Posts: 5,997
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Re: Murphy U472
Electrolytics of this age are generally pretty reliable although it is best to apply power gently to reform them. Don't think I replaced the one in my U472.
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8th Oct 2019, 5:49 pm
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#6 |
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Octode
Join Date: Jun 2005
Location: Sheffield, South Yorkshire, UK.
Posts: 1,227
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Re: Murphy U472
Well ,the red terminal gave 72 UF and 1.8R but the other side gave ' Diode , Vf =...'. There was a loud noise so I switched off. I was on a limiter.
I am planning to restuff. |
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8th Oct 2019, 6:07 pm
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#7 |
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Dekatron
Join Date: Aug 2013
Location: Wigan, Greater Manchester, UK.
Posts: 9,431
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Re: Murphy U472
I don’t have any but Cricklewood have these, probably CPC, RS and Farnell have similar ones.
https://www.cricklewoodelectronics.com/47H450.html Was the loud noise from the smoothing can? They can explode and when they do they usually spay silver foil over the chassis, you don’t want to be too near if the fail.
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Frank |
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8th Oct 2019, 6:11 pm
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#8 |
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Octode
Join Date: Jun 2005
Location: Sheffield, South Yorkshire, UK.
Posts: 1,227
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Re: Murphy U472
I forgot to say that there was a hole leaking stuff near one terminal!
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22nd Oct 2019, 2:30 pm
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#9 |
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Octode
Join Date: Jun 2005
Location: Sheffield, South Yorkshire, UK.
Posts: 1,227
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Re: Murphy U472
I got some 50 uF caps very cheaply via China and they just arrived . I have fitted this new part across the rectifier to replace an old waxy but is it adequate as the Murphy notes say '1000 Vdc' ?
Last edited by Pete_kaye; 22nd Oct 2019 at 2:37 pm. |
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22nd Oct 2019, 7:45 pm
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#10 |
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Hexode
Join Date: Jan 2011
Location: Essex, UK
Posts: 396
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Re: Murphy U472
That one's okay as it is an X2 type and marked for 250V AC.
Gus. |
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25th Oct 2019, 1:09 pm
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#11 |
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Octode
Join Date: Jun 2005
Location: Sheffield, South Yorkshire, UK.
Posts: 1,227
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Re: Murphy U472
Thanks .It is now working well on Mw and LW with 2 new caps . However, there is just a high pitched squeal on VHF , with or without aerial. There is a hint of station at several points. The UCC85 valve is tested. Where to now?
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3rd Nov 2019, 12:25 pm
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#12 |
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Octode
Join Date: Jun 2005
Location: Sheffield, South Yorkshire, UK.
Posts: 1,227
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Re: Murphy U472
Sorted . As advised , I changed C23 and VHF came on . Subbing a better UCC85 gave all stations across the band; the previous one did not. It is now back in the case and working well- thanks to this site.
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