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

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Vintage Radio (domestic)
Register FAQ Forum Rules Calendar Mark Forums Read

Notices

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

Closed Thread
 
Thread Tools
Old 8th Apr 2009, 4:42 pm   #1
Ian B
Hexode
 
Join Date: May 2006
Location: Arlesey, Bedfordshire.
Posts: 318
Default KB Minuet distortion

My KB OB10 Minuet (Trader sheet 1345) sounds good for the first 15 minutes or so after switching on and then becomes distorted. R3 gets too hot to touch, but the voltages on the pins of V1 (6BE6) & V2 (6AT6) don't seem to alter from those specified. I have changed C17 and C20.

Am I barking up the wrong tree in assuming that either V1 or V2 is taking too much screen current and causing the distortion, or does R3 usually run hot? In which case I should be looking elsewhere.....

I don't have any spare valves for this set, so substitution is not an option at this stage.

Thanks in anticipation

Ian Blackbourn
Ian B is offline  
Old 8th Apr 2009, 4:50 pm   #2
Steve_P
Dekatron
 
Steve_P's Avatar
 
Join Date: Sep 2003
Location: Bolton
Posts: 6,537
Default Re: KB Minuet distortion

Well it sounds to me like the O/P valve may be going into grid current. You could check C4, R4, R11 and R13.

Try another speaker (does not have to match, just for a test) but I would suspect V4.

Might be worth checking C15 and C16.

Cheers,

Steve P.
__________________
If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?
Steve_P is offline  
Old 8th Apr 2009, 6:32 pm   #3
Ian B
Hexode
 
Join Date: May 2006
Location: Arlesey, Bedfordshire.
Posts: 318
Default Re: KB Minuet distortion

Thanks Steve, quick reply as usual!

I'll check as you suggest.

TTFN
Ian
Ian B is offline  
Closed Thread

Thread Tools



All times are GMT. The time now is 8:28 am.


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


Powered by vBulletin®
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Copyright ©2002 - 2014, S&P Technology.