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 16th Nov 2022, 10:43 am   #1
nigelr2000
Heptode
 
nigelr2000's Avatar
 
Join Date: Nov 2008
Location: North Walsham, Norfolk, UK.
Posts: 887
Default Bush DAC90 Rebuild

I have just done a re-build on a DAC90 and fitted Ed Dinning's brilliant autotransformer mod.
Once completed I tried it out and it worked well but was heterodyning really badly especially on Long wave.

A quick search here bought up this thread https://vintage-radio.net/forum/showthread.php?t=59495

This was the same trouble with mine, metallizing not connected so I dug out some conductive paint I bought several years ago thinking it would be useful
well now it has been, I put a blob on the rear side of the valve after a quick scrape to show the conductive surface and buried a thin wire in it clamped in place by a couple of turns of stiff wire and a small square of insulation tape to hold it down till the paint went off. I then ran the wire round the front of the valve and soldered it onto the earth pin and removed the stiff wires.

The result is that it works perfectly now and is stable. The mod is hardly noticeable unlike wrapping in foil.

A few pics of the unit and the transformer mod. The live is not shrink wrapped yet as I am awaiting the fuse holder to turn up. I can then box it up and send it back to the customer.

Another success and it now runs pretty cool as a bonus.
Attached Thumbnails
Click image for larger version

Name:	DSCN5194.jpg
Views:	217
Size:	92.4 KB
ID:	268177   Click image for larger version

Name:	DSCN5196.jpg
Views:	207
Size:	56.9 KB
ID:	268178   Click image for larger version

Name:	DSCN5197.jpg
Views:	230
Size:	99.5 KB
ID:	268179   Click image for larger version

Name:	DSCN5198.jpg
Views:	225
Size:	75.4 KB
ID:	268180   Click image for larger version

Name:	DSCN5199.jpg
Views:	196
Size:	81.3 KB
ID:	268181  

nigelr2000 is offline  
Old 16th Nov 2022, 1:17 pm   #2
60 oldjohn
Dekatron
 
Join Date: Dec 2004
Location: East Yorkshire, UK.
Posts: 3,917
Default Re: Bush DAC90 Rebuild

Quote:
Originally Posted by nigelr2000 View Post
I have just done a re-build on a DAC90 and fitted Ed Dinning's brilliant autotransformer mod.


Another success and it now runs pretty cool as a bonus.
I have done the mod on my DAC90, In effect turning it into the AC90 the circuit is at the bottom of the DAC90 manufactures sheet.

John.
__________________
My favourite text message "I'll be there in five minutes, if not read again"
60 oldjohn is online now  
Old 23rd Dec 2022, 4:11 pm   #3
telstar
Octode
 
Join Date: Dec 2003
Location: Leeds, West Yorkshire, UK.
Posts: 1,586
Default Re: Bush DAC90 Rebuild

I have yet to do the modification on my Bush DAC90 radio. Where can I obtain a fuse and holder from for the work, please?
Mike
telstar is offline  
Old 23rd Dec 2022, 4:16 pm   #4
telstar
Octode
 
Join Date: Dec 2003
Location: Leeds, West Yorkshire, UK.
Posts: 1,586
Default Re: Bush DAC90 Rebuild

Quote:
Originally Posted by nigelr2000 View Post
I have just done a re-build on a DAC90 and fitted Ed Dinning's brilliant autotransformer mod.
Once completed I tried it out and it worked well but was heterodyning really badly especially on Long wave.

A quick search here bought up this thread https://vintage-radio.net/forum/showthread.php?t=59495

This was the same trouble with mine, metallizing not connected so I dug out some conductive paint I bought several years ago thinking it would be useful
well now it has been, I put a blob on the rear side of the valve after a quick scrape to show the conductive surface and buried a thin wire in it clamped in place by a couple of turns of stiff wire and a small square of insulation tape to hold it down till the paint went off. I then ran the wire round the front of the valve and soldered it onto the earth pin and removed the stiff wires.

The result is that it works perfectly now and is stable. The mod is hardly noticeable unlike wrapping in foil.

A few pics of the unit and the transformer mod. The live is not shrink wrapped yet as I am awaiting the fuse holder to turn up. I can then box it up and send it back to the customer.

Another success and it now runs pretty cool as a bonus.
Hi. I have found some conductive paint that I bought from Halfords for rear window heating repairs. Hope that this will be suitable for my EF39 valve screening.
telstar is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 4:14 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.