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 15th Sep 2020, 3:03 pm   #21
John10b
Nonode
 
Join Date: Nov 2016
Location: Aberaeron, Ceredigion, Wales, UK.
Posts: 2,869
Default Re: Bush AC41

Yes same circuit but the Bush circuit shows the dial lamp winding, thought it might be helpful to see it.
John
John10b is online now  
Old 15th Sep 2020, 3:06 pm   #22
John10b
Nonode
 
Join Date: Nov 2016
Location: Aberaeron, Ceredigion, Wales, UK.
Posts: 2,869
Default Re: Bush AC41

Should have said shows dial lamp winding more clearly.
John
John10b is online now  
Old 15th Sep 2020, 3:13 pm   #23
Sinewave
Octode
 
Sinewave's Avatar
 
Join Date: May 2016
Location: Oxfordshire/Bucks borders, UK.
Posts: 1,604
Default Re: Bush AC41

I've replaced the flex, but I think I should gather some capacitors and replace all of the decoupling capacitors. I've got some film caps, but not every value I need, so I'll try to get an order in.
__________________
Avometer, vintage Fluke and Marconi collector. Also interested in vintage Yaesu and KW.
Sinewave is offline  
Old 15th Sep 2020, 3:14 pm   #24
Sinewave
Octode
 
Sinewave's Avatar
 
Join Date: May 2016
Location: Oxfordshire/Bucks borders, UK.
Posts: 1,604
Default Re: Bush AC41

Quote:
Originally Posted by John10b View Post
Should have said shows dial lamp winding more clearly.
John
That reminds me, it's been gotten at in the past, someone has had the lamps.
__________________
Avometer, vintage Fluke and Marconi collector. Also interested in vintage Yaesu and KW.
Sinewave is offline  
Old 15th Sep 2020, 4:02 pm   #25
Sinewave
Octode
 
Sinewave's Avatar
 
Join Date: May 2016
Location: Oxfordshire/Bucks borders, UK.
Posts: 1,604
Default Re: Bush AC41

What do you think the options are if necessary, for that metal cased two in one 32uF cap? I can only think, leave it in place and put two replacements underneath inside the chassis of the radio.
__________________
Avometer, vintage Fluke and Marconi collector. Also interested in vintage Yaesu and KW.
Sinewave is offline  
Old 15th Sep 2020, 4:16 pm   #26
cathoderay57
Nonode
 
Join Date: Oct 2017
Location: Bristol, UK.
Posts: 2,364
Default Re: Bush AC41

Occasionally you'll see these dual cans come up on eBay, but buying a used electrolytic is a case of buyer beware because you don't know its history or if or how it has been tested. Some people use Chinese capacitance testers on them but even if they show reasonable capacitance value they can leak dc like a sieve when you put 250v+ on them. Personally I do exactly what you have said - disconnect the twin can leaving it physically in place (unless it is oozing gunk), and strap axial (if available) replacements underneath. The more enthusiastic seek out radial replacements that are small enough, then scrape out the innards of the old can and stuff the 2 radials inside. Do be careful with your eyes if you do this as I recently (unusually for me) restuffed an 8uF electrolytic on an Eddystone 750 and when I pierced the seal the blighter erupted a jet of fluid at me. Cheers, Jerry
cathoderay57 is offline  
Old 15th Sep 2020, 9:08 pm   #27
John10b
Nonode
 
Join Date: Nov 2016
Location: Aberaeron, Ceredigion, Wales, UK.
Posts: 2,869
Default Re: Bush AC41

I would agree with Jerry, I have used the different options, worth taking a look at Cricklewood Electronics, they have some suitable capacitors.
John
John10b is online now  
Old 15th Sep 2020, 9:55 pm   #28
Graham G3ZVT
Dekatron
 
Graham G3ZVT's Avatar
 
Join Date: May 2010
Location: Greater Manchester, UK.
Posts: 18,676
Default Re: Bush AC41

Half an hour of your time and no one but you will know it's not original.
Attached Thumbnails
Click image for larger version

Name:	1 (1).jpg
Views:	119
Size:	104.8 KB
ID:	215767   Click image for larger version

Name:	2 (1).jpg
Views:	126
Size:	86.9 KB
ID:	215768   Click image for larger version

Name:	4 (1).jpg
Views:	122
Size:	80.8 KB
ID:	215769   Click image for larger version

Name:	5 (1).jpg
Views:	115
Size:	31.8 KB
ID:	215770   Click image for larger version

Name:	6 (1).jpg
Views:	127
Size:	70.9 KB
ID:	215771  

__________________
--
Graham.
G3ZVT
Graham G3ZVT is online now  
Old 16th Sep 2020, 10:29 pm   #29
Sinewave
Octode
 
Sinewave's Avatar
 
Join Date: May 2016
Location: Oxfordshire/Bucks borders, UK.
Posts: 1,604
Default Re: Bush AC41

Has anyone ever noticed that the trader sheet has different numbering and/or values for some of the capacitors compared with the separate schematic available?
__________________
Avometer, vintage Fluke and Marconi collector. Also interested in vintage Yaesu and KW.
Sinewave is offline  
Old 17th Sep 2020, 9:03 am   #30
Station X
Moderator
 
Station X's Avatar
 
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,192
Default Re: Bush AC41

Different component designations in Trader sheets when compared to manufacturer's service sheets is almost universal. That's why when talking someone through a repair it's essential that you're both singing from the same hymn sheet.
__________________
Graham. Forum Moderator

Reach for your meter before you reach for your soldering iron.
Station X is offline  
Old 17th Sep 2020, 1:44 pm   #31
Radio Tech
Nonode
 
Radio Tech's Avatar
 
Join Date: Dec 2012
Location: Bocking, near Braintree, Essex, UK.
Posts: 2,068
Default Re: Bush AC41

Try Changing all the waxies, a set this age will need those changed, but if it was me I would also replace the main smoothing cap and any other electrolyics

Ken
Radio Tech is offline  
Old 17th Sep 2020, 3:40 pm   #32
Sinewave
Octode
 
Sinewave's Avatar
 
Join Date: May 2016
Location: Oxfordshire/Bucks borders, UK.
Posts: 1,604
Default Re: Bush AC41

Yes, noted. I intend to replace all the waxies and electrolytics, but I'll not touch the tuned circuits at this point, if at all.
__________________
Avometer, vintage Fluke and Marconi collector. Also interested in vintage Yaesu and KW.
Sinewave is offline  
Old 23rd Sep 2020, 12:21 pm   #33
Sinewave
Octode
 
Sinewave's Avatar
 
Join Date: May 2016
Location: Oxfordshire/Bucks borders, UK.
Posts: 1,604
Default Re: Bush AC41

I've got some replacement caps. Whilst delving deeper, I found this under the rectifier valve. The valve looks ok, perhaps the previous rectifier went pop?
Attached Thumbnails
Click image for larger version

Name:	IMAG5470.jpg
Views:	113
Size:	96.7 KB
ID:	216244  
__________________
Avometer, vintage Fluke and Marconi collector. Also interested in vintage Yaesu and KW.
Sinewave is offline  
Old 23rd Sep 2020, 12:52 pm   #34
HamishBoxer
Dekatron
 
HamishBoxer's Avatar
 
Join Date: Aug 2007
Location: W.Butterwick, near Doncaster UK.
Posts: 8,923
Default Re: Bush AC41

This just looks like soot from a high dissipation resistor ,ie the wire wound.My only other thought is,I notice fresh soldering? Or,it looks pretty clean on one joint.
__________________
G8JET BVWS Archivist and Member V.M.A.R.S
HamishBoxer is offline  
Old 23rd Sep 2020, 1:34 pm   #35
Sideband
Dekatron
 
Sideband's Avatar
 
Join Date: Oct 2003
Location: Croydon, Surrey, UK.
Posts: 7,548
Default Re: Bush AC41

Just general dirt and muck from heat generated by the valves and that big wirewound etc. The rectifier runs hot so not unusual for this deposit. See it in a lot of valve radios. Nothing to worry about.
__________________
There are lots of brilliant keyboard players and then there is Rick Wakeman.....
Sideband is online now  
Old 23rd Sep 2020, 2:11 pm   #36
Sinewave
Octode
 
Sinewave's Avatar
 
Join Date: May 2016
Location: Oxfordshire/Bucks borders, UK.
Posts: 1,604
Default Re: Bush AC41

Thanks chaps. Well I'm back in the lab with some coffee, so I'll get started and see where I get.
__________________
Avometer, vintage Fluke and Marconi collector. Also interested in vintage Yaesu and KW.
Sinewave is offline  
Old 30th Sep 2020, 5:15 pm   #37
Sinewave
Octode
 
Sinewave's Avatar
 
Join Date: May 2016
Location: Oxfordshire/Bucks borders, UK.
Posts: 1,604
Default Re: Bush AC41

So, most capacitors replaced, leaving tuned circuits well alone.

Powered up, scoped the output of the rectifier, nice DC.

It's very quiet, nothing heard at all. The occasional note heard when turning the tuning dial.....
__________________
Avometer, vintage Fluke and Marconi collector. Also interested in vintage Yaesu and KW.
Sinewave is offline  
Old 30th Sep 2020, 5:53 pm   #38
HamishBoxer
Dekatron
 
HamishBoxer's Avatar
 
Join Date: Aug 2007
Location: W.Butterwick, near Doncaster UK.
Posts: 8,923
Default Re: Bush AC41

Time for some voltage checks,starting with the HT.
__________________
G8JET BVWS Archivist and Member V.M.A.R.S
HamishBoxer is offline  
Old 30th Sep 2020, 6:46 pm   #39
Sinewave
Octode
 
Sinewave's Avatar
 
Join Date: May 2016
Location: Oxfordshire/Bucks borders, UK.
Posts: 1,604
Default Re: Bush AC41

Well the HT from the rectifier sits at around 250v. I'll need to get some test voltages for other areas.
__________________
Avometer, vintage Fluke and Marconi collector. Also interested in vintage Yaesu and KW.
Sinewave is offline  
Old 30th Sep 2020, 9:29 pm   #40
cathoderay57
Nonode
 
Join Date: Oct 2017
Location: Bristol, UK.
Posts: 2,364
Default Re: Bush AC41

Good idea to compare measured anode, & grid 2 (screen) voltages against those quoted in the service data. These will tell you something about how the valve is performing, together with the total current it is passing calculated by measuring the cathode voltage divided by the measured value of the cathode resistor. Also do you hear a buzz from the speaker when touching the volume control slider ( with volume turned up, obviously) via a screwdriver blade? Cheers, Jerry
cathoderay57 is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 9:00 pm.


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.