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.

Reply
 
Thread Tools
Old 1st Oct 2023, 6:13 pm   #1
sexton_mallard
Heptode
 
sexton_mallard's Avatar
 
Join Date: Sep 2013
Location: Ellesmere, Shropshire, UK & Co. Cork, Ireland.
Posts: 521
Default Ultra R656 Mains and battery portable

Curiosity got the better of me and this candidate on the front of the Rountoit was taken to the shed for an assessment. A relative who once worked in the TV hire and repair trade kindly gave me this set. The instruction and guarantee cards were still inside dated from December 1950 (pictured). A quick check for any wiring or other shorts was done and then a gentle wake up on a 42w dim bulb. The dropper resistors look a bit crumbly but have continuity and some questionable wiring needs tidying up.

The DC EHT on the reservoir electrolytic started to climb over 100V DC and the bulb brightness settled down proving there was some life still in the metal rectifier and the mains reservoir can.
Attached Thumbnails
Click image for larger version

Name:	20231001_175011.jpg
Views:	187
Size:	44.5 KB
ID:	285850   Click image for larger version

Name:	20231001_175108.jpg
Views:	175
Size:	64.3 KB
ID:	285851   Click image for larger version

Name:	20231001_175031.jpg
Views:	155
Size:	51.7 KB
ID:	285852   Click image for larger version

Name:	20231001_175051.jpg
Views:	139
Size:	55.2 KB
ID:	285853   Click image for larger version

Name:	20231001_175044.jpg
Views:	108
Size:	47.7 KB
ID:	285854  

__________________
Dom

Less snakes...more ladders!

Last edited by sexton_mallard; 1st Oct 2023 at 6:18 pm.
sexton_mallard is offline   Reply With Quote
Old 1st Oct 2023, 6:28 pm   #2
vinrads
Dekatron
 
Join Date: Feb 2009
Location: Chesterfield, Derbyshire, UK.
Posts: 3,791
Default Re: Ultra R656 Mains and battery portable

Hi Dom, looks a nice example ,when you say EHT I hope not ! does the radio work I see one or two waxy capacitors I would change these on sight , Mick.
vinrads is offline   Reply With Quote
Old 1st Oct 2023, 9:10 pm   #3
sexton_mallard
Heptode
 
sexton_mallard's Avatar
 
Join Date: Sep 2013
Location: Ellesmere, Shropshire, UK & Co. Cork, Ireland.
Posts: 521
Default Re: Ultra R656 Mains and battery portable

Quote:
Originally Posted by vinrads View Post
Hi Dom, looks a nice example ,when you say EHT I hope not ! does the radio work I see one or two waxy capacitors I would change these on sight , Mick.
Ha ha Thanks Mick. I have telly terminology on my mind from another thread! This set is my introduction to valve battery portables and once sorted on mains, I plan to create a battery pack for true portable use for the craic especially on visits to family in Essex with this set blasting out Radio Caroline! The usual replacement of waxies and any significantly out of whack resistors will be done.

I'll make sure not to overrun the valve heaters - I have some experience of this with the DM70 magic eye valve on another set.
__________________
Dom

Less snakes...more ladders!

Last edited by sexton_mallard; 1st Oct 2023 at 9:27 pm. Reason: Readability
sexton_mallard is offline   Reply With Quote
Old 1st Oct 2023, 10:33 pm   #4
sexton_mallard
Heptode
 
sexton_mallard's Avatar
 
Join Date: Sep 2013
Location: Ellesmere, Shropshire, UK & Co. Cork, Ireland.
Posts: 521
Default Re: Ultra R656 Mains and battery portable

Some more pictures. Bean can for scale. The back of the case is particularly attractive. The socket in the centre is for an aerial. This set predates the famous Coronation Twin which I think was released in 1953. The case will be deep cleaned when the chassis is out.
Attached Thumbnails
Click image for larger version

Name:	20231001_222734.jpg
Views:	107
Size:	96.2 KB
ID:	285858   Click image for larger version

Name:	20231001_222714.jpg
Views:	115
Size:	85.5 KB
ID:	285859  
__________________
Dom

Less snakes...more ladders!
sexton_mallard is offline   Reply With Quote
Old 1st Oct 2023, 11:00 pm   #5
McMurdo
Dekatron
 
McMurdo's Avatar
 
Join Date: Jun 2009
Location: Staffordshire Moorlands, UK.
Posts: 5,320
Default Re: Ultra R656 Mains and battery portable

I wouldn't get your hopes up about these 'blasting out' anything! They're ok enough for the kitchen or bedroom but they do have similar valves to those suitcase portables and have a pretty modest output.
__________________
Kevin
McMurdo is offline   Reply With Quote
Old 21st May 2024, 6:29 am   #6
Cobaltblue
Moderator
 
Cobaltblue's Avatar
 
Join Date: Dec 2010
Location: Exeter, Devon and Poole, Dorset UK.
Posts: 6,953
Default Re: Ultra R656 Mains and battery portable

Re-opened by request.
Cheers
Mike T
__________________
Invisible airwaves crackle with life or at least they used to
Mike T BVWS member.
www.cossor.co.uk
Cobaltblue is offline   Reply With Quote
Old 21st May 2024, 9:14 am   #7
sexton_mallard
Heptode
 
sexton_mallard's Avatar
 
Join Date: Sep 2013
Location: Ellesmere, Shropshire, UK & Co. Cork, Ireland.
Posts: 521
Default Re: Ultra R656 Mains and battery portable

Returning to this little set, further checks and tests showed the mains reservoir capacitor to be in good health. The mains and heater droppers were also testing OK despite looking a bit scruffy from losing their green coating. The finned selenium rectifier unfortunately was wilting with HT volts dropping to just 60 volts at the HT dropper tapping from running the set at mains voltage.

A temporary silicon diode and power resistor was bridged across and then the voltage carefully stepped up from 15w to a 60w dim bulb to get bang on 85v DC HT at the HT dropper tapping and about 7.5v for the heaters.

A very faint R4 on LW could be heard. A good speaker was subbed with no change and then a spare output transformer was clipped on and a better but still weak R4 could be heard. The secondary winding resistance was in the order of megaohms so it could be O/C. I will give the rectifier the benefit of the doubt once the suspect caps are replaced in case the assumed higher current draw was dragging it down. The mains reservoir cap remained cool and there was no hum from the speaker. MW appeared to be dead but this will be looked at once the output transformer and rectification was resolved.

The buzz from getting a long dormant little radio alive again never goes away and I stood at the shed door with the lights off looking up at a clear moonlit sky marvelling how we can still (just) enjoy broadcast radio. The valve heaters just about visibly glowing in the moonlight. After listening to the 11pm news I switched off. I wondered what was the last programme this little set played before being retired.

The next step is the usual replacement of higher value capacitors that are nearly all split lengthways. The three waxies look brand new in comparison but will be replaced as a matter of course. This set appears to have been stored in a damp place for many years which may also explain the crumbling dropper cement perhaps and the split brown plastic capacitor cases.
__________________
Dom

Less snakes...more ladders!
sexton_mallard is offline   Reply With Quote
Old 21st May 2024, 9:35 pm   #8
clockman
Pentode
 
Join Date: Jul 2020
Location: Borehamwood, Hertfordshire, UK.
Posts: 222
Default Re: Ultra R656 Mains and battery portable

I have a few of these sets as it's my favorite model once you have made the battery packs you can go out in the garden and enjoy lovely reception from a 50 year old great sounding vintage radio The Ultra Coronation Twin Thomas
clockman is offline   Reply With Quote
Old 24th May 2024, 4:14 pm   #9
sexton_mallard
Heptode
 
sexton_mallard's Avatar
 
Join Date: Sep 2013
Location: Ellesmere, Shropshire, UK & Co. Cork, Ireland.
Posts: 521
Default Re: Ultra R656 Mains and battery portable

The output transformer primary is in fact O/C but I have a spare generic RS transformer which I'm testing with as a possible replacement. The output valve is a Pinnacle branded DL94 which I believe is a sensible replacement to the 1P11 in the service sheet according to The Valve Museum.
__________________
Dom

Less snakes...more ladders!
sexton_mallard is offline   Reply With Quote
Reply

Thread Tools



All times are GMT +1. The time now is 2:07 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.