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 > General Vintage Technology > Success Stories

Notices

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!

Closed Thread
 
Thread Tools
Old 5th Jun 2011, 6:28 pm   #1
Cre8anet
Pentode
 
Cre8anet's Avatar
 
Join Date: Nov 2005
Location: Banbury, Oxfordshire, UK.
Posts: 145
Default Return of Cossor 1049... (second installment)

..more Monster-'scope discoveries, specially for any Cossor or 1049 fans:

See pics and thanks again to Ken, who also provided resources towards fix
(BTW, these go with the running success story here: https://www.vintage-radio.net/forum/showthread.php?t=49496)
:

(1) alternative to v22?? (a bit whacky, I admit) Cossor seemed keen on the 61BT tube. Yet to find easy replacements! (unless I want to waste EL38's with 3X power-handling). With little to lose, I spotted 6BQ6 has decent plate-volts (hurrah!).. but almost 2x I-fil (boo)...

So I tried 12BQ6 just for fun (yes, I know, a 12V tube in place of a 6V one... but I always did prefer experimental physics to precision engineering).


Results are so far so good in v22, but perhaps I should try swapping v15 this way instead... on basis it pulls less current?? Will keep you posted

(2) More gone-hi carbon power resistors. This time, to my surprise, both 15W glazed 56K's gone o/c. Both identical. These are R77 and R79, so result was no A1 trace. Now trace almost restored.. just too far -ve, so more resistors gone-hi I expect.

(3) Same again, EHT arcing is still a problem. Cotton-buds and meths must come out again but it's a bit hit and miss!

(4) Yet again, all caps seem fine... once again the famous Cossor electrolytic-less scope wins-out in this round.

Bottom line: if you restore a cossor of this era, expect to replace a LOT of fat carbon resistors. (See also first installment in link above).

Have fun!

Dave
Attached Thumbnails
Click image for larger version

Name:	04062011179.jpg
Views:	147
Size:	35.8 KB
ID:	52011   Click image for larger version

Name:	04062011178.jpg
Views:	152
Size:	73.1 KB
ID:	52012   Click image for larger version

Name:	04062011177.jpg
Views:	140
Size:	81.3 KB
ID:	52013  
__________________
~~~~~~May your Waves be Long~~~~~~
Cre8anet is offline  
Closed Thread

Thread Tools



All times are GMT. The time now is 8:47 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 - 2021, vBulletin Solutions, Inc.
Copyright ©2002 - 2021, Paul Stenning.