UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Vintage Radio (domestic)

Notices

Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only.

Closed Thread
 
Thread Tools
Old 22nd May 2006, 8:28 pm   #1
PaulR
Dekatron
 
PaulR's Avatar
 
Join Date: Oct 2003
Location: Southport Lancashire, UK.
Posts: 3,221
Default Murphy coupling capacitor values.

A friend has asked me to have a look at a Murphy A262 which is working but somewhat distorted.

I haven't actually got it yet, but an obvious starting place is the final AF coupling capacitor. I have got part of the Trader sheet from this site (Paul - have you seen my emails about the apparently missing bits of the sheet?) and the value is shown as .005 uf. This seems a bit on the low side. Is it likely to be correct, or possibly a mis-print?

The nearest I have to hand is 0.047 - would the 10x over value make any difference?

Thanks

Paul
PaulR is offline  
Old 22nd May 2006, 8:39 pm   #2
paulsherwin
Moderator
 
paulsherwin's Avatar
 
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,787
Default Re: "That" capacitor on a Murphy A262

Hi Paul. Full circuit here: http://www.******************************/A262.jpg

Murphy did tend to use a low value capacitor at this point. I found that increasing the value in my A684 actually helped remove some troublesome hum. An 0.047uF should be fine in this position.

Here's the A684 so you can compare it: http://www.******************************/A674.jpg

Best regards, Paul

Last edited by Darren-UK; 20th Jul 2007 at 2:50 pm. Reason: Removed reference to another, now deleted, thread.
paulsherwin is offline  
Old 23rd May 2006, 9:11 pm   #3
PaulR
Dekatron
 
PaulR's Avatar
 
Join Date: Oct 2003
Location: Southport Lancashire, UK.
Posts: 3,221
Default Re: "That" capacitor on a Murphy A262

Well, I have replaced the capacitor and shivered at the sight of all the Hunts over the rest of the set!

The performance is astounding. Even on the internal aerial VHF is very powerful and clear. Murphy certainly knew how to make them!

Paul
PaulR is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 2:19 am.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.