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 4th Feb 2009, 5:59 pm   #1
AlanBeckett
Rest in Peace
 
Join Date: Dec 2008
Location: Burton upon Trent, East Staffordshire, UK.
Posts: 1,686
Default Ancient Ekco Power Unit (AC10/20)

Hello everyone again.
This is another fishing expedition among your extensive knowlege.
See attached pictures. I came across this accidentally. However, here it is, at a good home. It's about 9" x 5" x 3 1/4 deep, and made of brown Bakelite, slightly cracked.
There's a hand-written label stuck on which says 1920s.
On the back is stamped:-
AC 10/20
4251
REGD. 782513
PAT No. 262567.
There's also a Westinghouse Patent label which I hope you can see in the picture.
Also on the back is a mains voltage selector and a 'mA' selector.
On the front are a range of sockets - again I hope you can read them.
I haven't tried to do anything with it yet. As you can probably see the mains cable has been cut off, and anyway its insulation is falling off. The rectifier measures about 100k in both directions and the choke (?) measures about 50k. The triple electrolytic shows no sign of 'charging' from the AVO.
My guess is that it's meant as an HT Battery Eliminator. I've read the Thread on battery eliminators, but they seem much more up-market than this one (I really like the idea of chargeing the accumulator when the radio is off!)
So, before I'm tempted to do anything silly has anyone come across a similar one? When was it made? Is that a Copper Oxide or Selenium rectifier? What is the purpose of the 'mA' selector on the back? What would I expect from the various sockets on the front? etc, etc.
Here's looking forward to some interesting posts.
Alan
Attached Thumbnails
Click image for larger version

Name:	SmallFront.jpg
Views:	355
Size:	111.0 KB
ID:	22876   Click image for larger version

Name:	SmallInside.jpg
Views:	351
Size:	93.3 KB
ID:	22877   Click image for larger version

Name:	SmallBack.jpg
Views:	294
Size:	133.8 KB
ID:	22878   Click image for larger version

Name:	SmallPanel.jpg
Views:	226
Size:	189.3 KB
ID:	22879   Click image for larger version

Name:	SmallCaps.jpg
Views:	259
Size:	150.4 KB
ID:	22880  


Last edited by Station X; 4th Feb 2009 at 6:18 pm. Reason: To comply with forum rules.
AlanBeckett is offline  
Old 4th Feb 2009, 6:21 pm   #2
Brian R Pateman
Nonode
 
Brian R Pateman's Avatar
 
Join Date: Jun 2005
Location: Western Lake District, Cumbria (CA20) - UK
Posts: 2,136
Default Re: Ancient EKCO Power Unit

You are right Alan. This is a 1930s battery eliminator. If I recall correctly there was a thread on these a couple of years ago.

This was what the E K Cole company, better known as Ekco, started out manufacturing. They were made for years. This one looks to be in good condition considering its age.

Regards,
__________________
Brian
Brian R Pateman is offline  
Old 4th Feb 2009, 6:28 pm   #3
AlanBeckett
Rest in Peace
 
Join Date: Dec 2008
Location: Burton upon Trent, East Staffordshire, UK.
Posts: 1,686
Default Re: Ancient EKCO Power Unit

Brian,
Ah, you think it's 30s. OK. I did wonder because of the rectifier. When were they invented and when did the Westinghouse Patent run out? A couple of other thing I forgot to mention: The whole thing is held together with Aluminium rivets, which make it very difficult to get at anything. Also, there are a couple of 'variable' resistors tucked under the top panel. They appear to be carbon rods with sliders.
Alan
AlanBeckett is offline  
Old 4th Feb 2009, 6:32 pm   #4
Peter.N.
Dekatron
 
Join Date: Jul 2008
Location: Charmouth, Dorset, UK.
Posts: 3,601
Default Re: Ancient EKCO Power Unit

First time I have actually seen one of those. Battery eliminator as Brian says. EK Cole originally made Bakalite mouldings and started producing these when all the houses were built in Southend with mains electricity, most people still had battery sets so the demand was huge, they really made Ekco.
Peter.N. is offline  
Old 4th Feb 2009, 6:36 pm   #5
Station X
Moderator
 
Station X's Avatar
 
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,192
Default Re: Ancient EKCO Power Unit

Rivets can easily be drilled out and replaced with nuts and screws if necessary.

S.G denotes Screen Grid Supply. The other supply is HT to the anodes. H, M and L denotes High Medium and Low.

It might be useful to reverse engineer the unit and produce a circuit diagram.
__________________
Graham. Forum Moderator

Reach for your meter before you reach for your soldering iron.
Station X is online now  
Old 4th Feb 2009, 6:56 pm   #6
Darren-UK
Retired Dormant Member
 
Join Date: Apr 2003
Location: Blackpool, Lancashire, UK.
Posts: 4,061
Default Re: Ancient EKCO Power Unit

There's some info on these units here although I note the AC10 isn't mentioned.
Darren-UK is offline  
Old 4th Feb 2009, 7:20 pm   #7
AlanBeckett
Rest in Peace
 
Join Date: Dec 2008
Location: Burton upon Trent, East Staffordshire, UK.
Posts: 1,686
Default Re: Ancient EKCO Power Unit

Graham,
Yes, but it's always a bit fraught. I'll have to do it in the end, I was just hoping someone had already worked it all out.
Darren,
That's a splendid link. Perhaps the 10/20 relates to the current 'link' on the back. But what changes when the link is changed? I fear the reverse engineering will be the only anwer.
Alan
AlanBeckett is offline  
Old 4th Feb 2009, 7:25 pm   #8
Paul_RK
Dekatron
 
Paul_RK's Avatar
 
Join Date: Nov 2003
Location: Fakenham, Norfolk, UK.
Posts: 4,246
Default Re: Ancient EKCO Power Unit

I've one somewhere in the same case, but can't remember exactly what it does (or did ). I expect the mA settings at the rear are for adjustment according to the anode current demand of the output valve in use, to maintain the expected voltages at the various front panel sockets.

Paul
Paul_RK is offline  
Old 4th Feb 2009, 7:40 pm   #9
AlanBeckett
Rest in Peace
 
Join Date: Dec 2008
Location: Burton upon Trent, East Staffordshire, UK.
Posts: 1,686
Default Re: Ancient EKCO Power Unit

Paul,
That's logical - a sort of crude method of maintaining 120 volts (say) at different loads. However, I can't see any extra resistors. I've just noticed that the 'mA' selector is on the 'output' side of the transformer, and there appear to be 4 'output' wires (see picture) so perhaps it simply changes the output voltage. Bearing in mind that the losses from there on will be pretty constant a bit more voltage from the transformer would allow more current to be drawn at the same output voltage.
Alan
AlanBeckett is offline  
Old 4th Feb 2009, 8:34 pm   #10
Station X
Moderator
 
Station X's Avatar
 
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,192
Default Re: Ancient EKCO Power Unit

I reverse engineered a similar Regentone W1F battery eliminator a few years back. If you've got Paul's Service Data DVD you'll find it on there.

Not very complicated. Mains Transormer, Rectifier, CLC filter and a few resistors.
__________________
Graham. Forum Moderator

Reach for your meter before you reach for your soldering iron.
Station X is online now  
Old 4th Feb 2009, 9:20 pm   #11
Tim
Dekatron
 
Tim's Avatar
 
Join Date: Jan 2003
Location: Bradford on Avon, Wiltshire, UK.
Posts: 3,301
Default Re: Ancient EKCO Power Unit

I expect someone thought it was 1920's because it has a 7xxxxx reg. des. number. The rule of thumb is 700,000's were 1920's
( according to an antiques guide I saw once). Maybe the design WAS late 20's so it's very possible actual item early 30's?
Nice thing though.
__________________
"Nothing is as dangerous as being too modern;one is apt to grow old fashioned quite suddenly."
Tim is offline  
Old 4th Feb 2009, 9:26 pm   #12
AlanBeckett
Rest in Peace
 
Join Date: Dec 2008
Location: Burton upon Trent, East Staffordshire, UK.
Posts: 1,686
Default Re: Ancient EKCO Power Unit

Graham,
I fear I haven't got Paul's DVD. However, I suspect that's not worrying him much as I keep buying individual ones! Also, I've got some books which cover the era I'm most interested in.
Tim,
That's brilliant. I never thought of looking at it that way.
Alan
AlanBeckett is offline  
Old 4th Feb 2009, 9:44 pm   #13
Paul_RK
Dekatron
 
Paul_RK's Avatar
 
Join Date: Nov 2003
Location: Fakenham, Norfolk, UK.
Posts: 4,246
Default Re: Ancient EKCO Power Unit

Just found a summary of RD nos. at http://www.great-glass.co.uk/glass%20notes/regnos.htm , according to which 779292 is 1933's earliest known number and 789035 the earliest for 1934. 1933 does sound right to me for this one, I think the bronze case Ekco units tend to be a little older.

Paul
Paul_RK is offline  
Old 4th Feb 2009, 10:02 pm   #14
Hermit6345
Rest in Peace
 
Hermit6345's Avatar
 
Join Date: Oct 2006
Location: North Wiltshire, UK.
Posts: 638
Default Re: Ancient EKCO Power Unit

I have an Ekco K12 in daily use. It's very simple inside. Charges my 25AH Cyclon at about 150mA. Switch on top switches between charging voltage and HT out when the set is to be used. Transformer and choke inside mine look a bit more "modern" than those pictured in the link. I wonder when Ekco stopped making eliminators?

Ian.
Attached Thumbnails
Click image for larger version

Name:	DSCF0080.JPG
Views:	363
Size:	110.3 KB
ID:	22889  
Hermit6345 is offline  
Old 4th Feb 2009, 10:14 pm   #15
AlanBeckett
Rest in Peace
 
Join Date: Dec 2008
Location: Burton upon Trent, East Staffordshire, UK.
Posts: 1,686
Default Re: Ancient EKCO Power Unit

Paul,
Thats splendid. I think that nails it down nicely.

Ian,
That looks very swish. What is the HT output, and at what current? I'm just interested about what I might expect.
Alan
AlanBeckett is offline  
Old 4th Feb 2009, 10:34 pm   #16
mickjjo
Rest in Peace
 
mickjjo's Avatar
 
Join Date: Jul 2004
Location: Dartford, Kent, UK.
Posts: 1,661
Default Re: Ancient EKCO Power Unit

I have one of the earlier Ekco HT only units, a No2 A10, Possibly from 1926 as shown HERE , All original with a long copper oxide rectifier, Still gives it's rated output of 10mA at 120v.

Regards, Mick.
mickjjo is offline  
Old 4th Feb 2009, 11:07 pm   #17
Hermit6345
Rest in Peace
 
Hermit6345's Avatar
 
Join Date: Oct 2006
Location: North Wiltshire, UK.
Posts: 638
Default Re: Ancient EKCO Power Unit

Alan,

The K12 is rated at 12mA. At 10mA, the voltage from mine is 125 volts which is about right for a new 120 volt HT battery. The 12 mA rating on the HT output is reduced if you are feeding a screened grid at say 1.5mA from one of the other sockets. My radio uses a 220OT and this psu suits that quite nicely. Suffice it to say that I have never had to remove my accumulator to charge it and it's been in operation for nine months and used daily. The K12 remains as cool as a cucumber, probably as a result of snipping the wires to the metal rectifier and replacing with a 1N400 something. Also gutted the can with the reservoir/smoothing caps in and replaced with modern and much higher capacitance units. Then refilled with wax. Fitted new mains lead and grommet, replaced charger output leads. Added loading resistor to keep off- load HT voltage at about 150 volts. Thought about zenering output to 130 volts, but it would not be as original then. All in all I am pleased with it. Well worth getting yours going especially if you have a 1930s radio to run from it.
Hermit6345 is offline  
Old 5th Feb 2009, 12:05 pm   #18
AlanBeckett
Rest in Peace
 
Join Date: Dec 2008
Location: Burton upon Trent, East Staffordshire, UK.
Posts: 1,686
Default Re: Ancient EKCO Power Unit

Gentlemen,
That definitely answers my question about what to expect. As far as a '30s radio is concerned I haven't got one at the moment. My earliest memories of radios, from the '50s, when we lived in a house with no mains suppy, was of just such a set. We had two accumulators (one was being recharged at the local cycle shop while the other was being used), plus of course a GB battery and a steady drip of HT batteries. My parents used to complain about the cost of the HT batteries! So I guess my next step is to carefully take it to bits, sort out the circuit and fix what needs fixing. Then, a battery set to try it with.
Mods,
I think I probably put this thread in the wrong place as usual. I'd like to keep it going as I'm likely to need some more advice and guidance as I do the job. Could you move it to a more sensible place please?
Alan
AlanBeckett is offline  
Old 5th Feb 2009, 2:26 pm   #19
John M0GLN
Octode
 
John M0GLN's Avatar
 
Join Date: Jan 2004
Location: Southport, Merseyside, UK.
Posts: 1,156
Default Re: Ancient EKCO Power Unit

From a 1933-34 catalogue.

John
Attached Thumbnails
Click image for larger version

Name:	eliminator1.jpg
Views:	292
Size:	145.1 KB
ID:	22920   Click image for larger version

Name:	eliminator2.jpg
Views:	266
Size:	145.9 KB
ID:	22921  
John M0GLN is online now  
Old 5th Feb 2009, 2:58 pm   #20
Station X
Moderator
 
Station X's Avatar
 
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,192
Default Re: Ancient EKCO Power Unit

Quote:
Originally Posted by AlanBeckett
I think I probably put this thread in the wrong place as usual. I'd like to keep it going as I'm likely to need some more advice and guidance as I do the job. Could you move it to a more sensible place please?
Alan
It's in the right place. If you're looking for advice on repairing it start a new thread in Vintage Radio Domestic.
__________________
Graham. Forum Moderator

Reach for your meter before you reach for your soldering iron.
Station X is online now  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 11:58 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.