Featured
Latest
Holey DAC10 Batman!
 
Share:
Notifications
Clear all

Forum 141

Radio Holey DAC10 Batman!

27 Posts
8 Users
21 Likes
112 Views
slidertogrid
(@slidertogrid)
Posts: 1015
Honorable Member Registered
Topic starter
 

I bought this set cheaply last year because I have one with a less than perfect dial glass. For the price it was worth it for the glass alone. I hate breaking vintage stuff though so it was put to one side...

Today while clearing some junk out of the shed I saw it again looking sad and dirty on the shelf so I brought it in and gave it a wipe over with a damp cloth. Gawd knows what the thinking behind the holes drilled in it were! The biggest is above the output valve and rectifier maybe an aid to ventilation? The smaller ones in the side look as there may have been something fixed to the side...

The set has some good points, the dial glass is sound, the station/waveband labels are present, the vulnerable cream surround is crack free, it even has the little Bush tree label still on the front, albeit a little worn. Inside the chassis is not bad, I have certainly seen worse! Finally the cabinet is the less common 'maroonie brown' plain Bakelite rather than the usual brown with black swirls.

So what to do cabinet wise? My thoughts are fill the holes, rub down, touch in to match as best as possible and polish. Or fill and respray the cabinet a non standard colour? Or.. I have just been watching an upcycle programme on TV, they took an artist's easel and flicked it with brightly coloured paint, it was a little bit like the KB BM20 radio with the speckled finish that makes so much money. It made me think how about spray the case either cream or matt black and then 'flick it' with a selection of colours to give a speckled effect?  I don't consider this to be too sacrilegious as a DAC10 isn't a rare or valuable set, It could have been broken for parts in any case. Worse case it could always be stripped and polished back. With the holes filled it is never going to be mint or original in any case, those days have long passed! 

Any ideas or opinions as to what I should do? I am going to see how much work the chassis needs and if the speaker is serviceable before I go too much further...

20240327 141824
20240327 141900
20240327 141829
20240327 141911
20240327 142000
20240327 141824
 
Posted : 27/03/2024 3:17 pm
LSmith, ntscuser and Lloyd reacted
jcdaze
(@jcdaze)
Posts: 156
Reputable Member Registered
 

@slidertogrid William Duck and his assistant T.J.Pinker were hiring out pianos from that very address on the back cover label in 1848. Company was still in the musical instrument business until 2011. Lots of information about that company on the Bath-Heritage website.

 
Posted : 27/03/2024 3:50 pm
Cathovisor and ntscuser reacted
Nuvistor
(@nuvistor)
Posts: 4609
Famed Member Registered
 

@slidertogrid The hole on top looks like it would take a lamp holder, perhaps some thought of upcycling many years ago with a lamp and shade on top with a switch screwed to the side. Or were the holes on the side for a timer to switch radio and light on as an alarm clock.

Yes I know I should get out more.

Frank

 
Posted : 27/03/2024 4:17 pm
ntscuser reacted
slidertogrid
(@slidertogrid)
Posts: 1015
Honorable Member Registered
Topic starter
 

@jcdaze That was an incredible run! You don't get firms like that anymore! 

@nuvistor Frank, you may be right! Maybe it was turned into a homemade radio/lamp/alarm! I'll check to see if there is any modifications to the mains connections when i get the chassis out.

 
Posted : 27/03/2024 4:38 pm
slidertogrid
(@slidertogrid)
Posts: 1015
Honorable Member Registered
Topic starter
 

I have taken the chassis out and put it on the bench. I brought it up on the Variac slowly, starting at 100V taking it up to 240 over about an hour. There didn't seem a lot of point in starting at below 100V because the UY41 wouldn't create any HT below that. 

The Audio amplifier is working a bit as I get a low hum when touching the volume control other than that the chassis is not doing a lot!  The wax capacitors are sticky and looking sick so I replaced one at a time, testing after each replacement and checking each capacitor when removed. Every capacitor read miles off value, some leaky and a couple open circuit, confirming my suspicions that they are all past their use by date!  

Still no reception though! I get various crackles as I rock the valves  I so will give the bases a clean next and if necessary then try a set of front end valves. If that doesn't improve matters I will get the meter out and see what the voltages around the valve bases are. The smoother seems to have reformed OK though there is very little background hum.

 

20240327 181344
20240327 165952
20240327 165702
20240327 164625

The speaker has been replaced previously I will have to see what it sounds like once it is working....

 
Posted : 28/03/2024 9:31 am
irob2345
(@irob2345)
Posts: 552
Honorable Member Registered
 

A guy in Oz fixed some holes in a 1936 bakelite cabinet - an Airzone Radiostar - for me 20 years ago. Colour looks very similar to yours.

https://www.radiomuseum.org/r/airzone_550.html

He used epoxy mixed with ground-up bakelite from beyond-redemption cabinets and a plug retrieved from a similar donor using a centre-less hole saw. Once cured, a cut and polish followed.

You would have to know where the hole used to be. You'd never find it otherwise.

 
Posted : 28/03/2024 10:41 am
Nuvistor reacted
slidertogrid
(@slidertogrid)
Posts: 1015
Honorable Member Registered
Topic starter
 

@irob2345 That is a good suggestion. I hadn't thought of using a plug cut from a donor. I was just going to fill the hole with car body filler... I think I have got a scrap Bakelite GEC cabinet in the shed I will check the colour. 😎 

 
Posted : 28/03/2024 12:52 pm
Boater Sam
(@boater-sam)
Posts: 500
Honorable Member Registered
 

Posted by: @slidertogrid

I have taken the chassis out and put it on the bench. I brought it up on the Variac slowly, starting at 100V taking it up to 240 over about an hour. There didn't seem a lot of point in starting at below 100V because the UY41 wouldn't create any HT below that. 

The Audio amplifier is working a bit as I get a low hum when touching the volume control other than that the chassis is not doing a lot!  The wax capacitors are sticky and looking sick so I replaced one at a time, testing after each replacement and checking each capacitor when removed. Every capacitor read miles off value, some leaky and a couple open circuit, confirming my suspicions that they are all past their use by date!  

Still no reception though! I get various crackles as I rock the valves  I so will give the bases a clean next and if necessary then try a set of front end valves. If that doesn't improve matters I will get the meter out and see what the voltages around the valve bases are. The smoother seems to have reformed OK though there is very little background hum.

 

-- attachment is not available -- -- attachment is not available -- -- attachment is not available -- -- attachment is not available --

The speaker has been replaced previously I will have to see what it sounds like once it is working....

Could be the oscillator is not running.  The twiddler hasn't been at it  I hope.  The  switches are a common problem and not easy to clean properly.

 

Boater Sam

 
Posted : 28/03/2024 7:56 pm
slidertogrid
(@slidertogrid)
Posts: 1015
Honorable Member Registered
Topic starter
 

@boater-sam Yes I hope it hasn't been twiddled, I had a Pye battery valve portable that someone had twiddled to death, Gawd knows why! It took me a while to realise the problem! I'll check the osc  tomorrow. I did wonder about the push button switches as I have had problems before on a DAC10 but the contacts that can be seen look clean, too clean! Someone has definitely been there. It makes me wonder why they replaced the speaker, cleaned the switches but didn't replace the capacitors as they must have been grotty at that time? Hopefully I'll get some time over the Easter holls...

 
Posted : 28/03/2024 9:28 pm
slidertogrid
(@slidertogrid)
Posts: 1015
Honorable Member Registered
Topic starter
 

I have made a bit of progress today. The problem was indeed the oscillator. I checked the anode and screen voltages of V1 the triode anode voltage was high which was a clue, I tried another valve and found it to be the same. Then while poking around checking voltages the set suddenly started working then just as suddenly stopped and nothing would coax it back to life.

The problem was no GB on the triode due to R3 220 Ohms being open circuit. When I unsoldered it one end fell off. Pushing it back together and checking it again it read 243 Ohms yet when in circuit it was definitely reading open. Now I would say it was probably caused by me when I changed the capacitors but the set didn't work before I changed the caps, So maybe I cured one fault and caused another!  That said someone had cleaned the valve pins and the wave change switch so maybe they were looking for the same fault as me?  Anyway it works now. Gain is a bit low and it isn't that loud on the stations it does receive, that may be down to the replacement speaker though. I will come back to the chassis and see if replacing any valves makes a difference. I have replaced the UY41 which brought the HT up 20 volts but didn't make any difference to performance.

The set is remarkably hum free most DAC sets have a bit of background hum but this is almost zero so the UL41 must be a good one, This set really was a bargain for a fiver! Having got this far with the chassis I have made a start on the cabinet, I gave the knobs a clean and then polished the back cover, I didn't wash the Bakelite I just carefully wiped it over with a damp cloth before polishing as I don't want to lose Duck, Son and Pinker! 

Once I have polished the front I will see about making a plug for the hole as suggested. I can fill the smaller holes in the side and touch them in. It looks as if it will stay it's original colour...

20240329 151042
20240329 142711
20240329 151121

 

 

 
Posted : 29/03/2024 3:45 pm
LSmith and Nuvistor reacted
Boater Sam
(@boater-sam)
Posts: 500
Honorable Member Registered
 

Good work! Its not common for the ends to fall off these resistors in my experience. The UL41 should not be quiet, these sets cane really get loud.

Boater Sam

 
Posted : 29/03/2024 7:03 pm
slidertogrid reacted
slidertogrid
(@slidertogrid)
Posts: 1015
Honorable Member Registered
Topic starter
 

I have had little time over the holiday but I have managed to do a bit more to the DAC10. I have cleaned, the chassis not that it was really dirty but it is better for a clean. Lubricated the tuning capacitor and pointer track which has taken away an annoying squeak and has probably reduced the strain on the drive cord, cleaned the diffuser, the dial lamps look reasonably new which is another bonus as they can be difficult to find if replacements are needed.

I had a quick check around the valve base voltages and all seem around what they should be I tried replacing the three 'front end' valves one by one to see if I could improve the gain and it is a little better as I can now pick up Caroline which I couldn't before. On strong stations the set produces fairly good volume, the speaker is not helping though as it is small and a bit muffled be the baffle that it is mounted on. I have tried a couple of bench speakers and they are better, so I may have to try and find a more suitable speaker that will fit if possible.

It's not really too much of a problem as it is loud enough just not as loud as one with the original speaker would be. I have filled the small holes in the side with filler next job is to see if I can find a bit of suitable Bakelite to make a plug for the largest hole. It has been an interesting project so far and just goes to show how much fun this hobby can be at almost zero cost.

20240402 152705
20240402 152659
20240402 152727

 

 

 
Posted : 02/04/2024 2:51 pm
LSmith reacted
Cathovisor
(@cathovisor)
Posts: 6418
Famed Member Registered
 

I seem to recall that the "flying saucer" loudspeaker used on the DAC10 is also used in some of the Collaro Micrograms. I'm giving serious thought to getting rid of all my record players bar one or two to clear some space (probably at RetroTech) and I think I may have a scrap one of them (woodworm). Failing that, who knows what I'll find when I go into the shed over the summer - I've not been in it for a few years. I do know that I have a plain brown DAC10 in there.

 
Posted : 02/04/2024 5:18 pm
slidertogrid
(@slidertogrid)
Posts: 1015
Honorable Member Registered
Topic starter
 

That is interesting Mike, I Have never had a Microgram I have seen a similar speaker in the lid of a Philips record player, I think... It is certainly a strange idea! I suppose a conventional speaker would have meant the DAC 10 would have been a lot deeper. 

Please let me know if you do find anything suitable, if your DAC 10 is rough and isn't saveable I would be interested in buying it for parts. 

Rich.

 
Posted : 02/04/2024 6:32 pm
slidertogrid
(@slidertogrid)
Posts: 1015
Honorable Member Registered
Topic starter
 

I'm getting there with the Bush. I have put the chassis and speaker back in. I cut a hole in the baffle that had been made for the replacement speaker to allow more sound out and now it is back in the cabinet the sound volume is fine, so it can stay like that unless the correct speaker does turn up. 

Today I found a damaged DAC90A cabinet in the shed, the Bakelite is dark enough but is brown with swirls, it will have to do, I am unlikely to find a plain dark maroon cabinet as a donor. I cut a couple of 'plugs' from the bottom of the scrap case one too small the other just slightly too big so I enlarged the hole in the back slightly and then used sandpaper to reduce the plug slightly until I had a snug fit. When I enlarged the hole from the swarf it was apparent how maroon the DAC10 is or was, I wonder if it has darkened over time?  I took precautions when cutting and sanding as I am aware that there is no knowing what fillers were used in Bakelite...

I have glued the plug in place and I will fill over it today so it can be rubbed down and polished back tomorrow. This repair is not going to be invisible by any means but it will do and after all is all part of it's history.

20240407 171123
20240407 171101
20240407 171109
20240407 181908

 

 
Posted : 07/04/2024 7:20 pm
Lloyd reacted
Cathovisor
(@cathovisor)
Posts: 6418
Famed Member Registered
 

Posted by: @slidertogrid

When I enlarged the hole from the swarf it was apparent how maroon the DAC10 is or was, I wonder if it has darkened over time?

They are indeed rather maroon in appearance - not as much as say, a Murphy U198 but it's certainly on the red side of brown. Some AC91s were this plain colour too.

 
Posted : 07/04/2024 7:35 pm
slidertogrid
(@slidertogrid)
Posts: 1015
Honorable Member Registered
Topic starter
 

I have filled around the plug and then 'dusted' it over with a couple of thin coats of Ford Rio brown just to disguise the filler. Then a good polish up and a further polish with a reddish brown shoe polish. This has improved the appearance of the front of the case as well as the colour was a little dull after it had been cut back. On the whole (hole! 😀) I am pleased with the result.  The repairs are not completely invisible but the set is now smart and presentable the wrong speaker and the filled holes are all part of the set's history. I am glad I didn't dismantle it for parts. 

The last few pictures of the finished set.

20240409 130218
20240409 130622
20240409 130638
 
Posted : 09/04/2024 12:30 pm
LSmith and Lloyd reacted
Cathovisor
(@cathovisor)
Posts: 6418
Famed Member Registered
 

By 'eck, you've done a splendid job there, Rich - it looks great! Amazing what a post-polish application of Cherry Blossom can do.

I'm almost minded now to go potholing in my front room and dig out my "Wireless For The Blind" DAC10, complete with transfer to restore. My first DAC10 was also a "Wireless For The Blind" set, but in my youth I removed it and polished it out... <fx: facepalm>

Considering I can see the box from where I'm sitting, it would also be instructive to restore my EBS23* to put alongside it.

 

*The EBS23 is the AC-only, export version of the DAC10.

 
Posted : 09/04/2024 12:53 pm
slidertogrid
(@slidertogrid)
Posts: 1015
Honorable Member Registered
Topic starter
 

Posted by: @cathovisor

, it would also be instructive to restore my EBS23* to put alongside it.

*The EBS23 is the AC-only, export version of the DAC10.

Hi Mike I have never heard of of an EBS23 does it have SW instead of LW As many export versions of UK sets did? That must be a very uncommon set. I would love to see a picture of it if you get chance.

The DAC10 that I have with a poor dial glass is also a Wireless for the blind set but I think the engraving has been removed or maybe they weren't all engraved?  It came from a friend decades ago, it was an obsolete set he got when WFTB went over to Roberts Transistorised sets, his brother had something to do with the charity. I think maybe he was a volunteer who delivered and collected the sets but I can't be sure, it was a very long time ago...  

This set is the reason I bought the holey one. Plan A was to use the dial glass from the holey set when I restored it.  It's in the spare room, I will pull it out and have a look, it's been waiting for 25 years or so....

 

 
Posted : 09/04/2024 2:57 pm
Cathovisor
(@cathovisor)
Posts: 6418
Famed Member Registered
 

Posted by: @slidertogrid

Hi Mike I have never heard of of an EBS23 does it have SW instead of LW As many export versions of UK sets did? That must be a very uncommon set. I would love to see a picture of it if you get chance.

Well, there's this: http://www.bushradio.co.uk/ebs23.html

It has a more colourful dial and the push-buttons on the top are for 3x SW, MW and "off". They're much less cluttered on the chassis as there's no preset tuning or indeed, a frame aerial.

I also have - I think - a boxed EU23 (the AC/DC version) and an empty box for an EU23. The EBS23 is less common (for some values of 'common') than the EU23.

BTW, grovelling round at the back of a store today (whilst looking for something else) I spotted a forlorn DAC10...

 
Posted : 09/04/2024 5:19 pm
slidertogrid reacted
Page 1 / 2
Share: