Need schematic for Ekco A218 - UK Vintage Radio Repair and Restoration Discussion Forum

brenda · 17th Jan 2007, 9:45 am

Just got all your service disks, Paul. Figures that the first radio I try to find in it isn't there. Murphy's Law.

If anyone has a schematic for this radio, it would be greatly appreciated.

Will also need a dial glass, if I ever get it working.

TIA

Brenda Ann

Dave Moll · 17th Jan 2007, 10:17 am

It doesn't appear to be in R&TVS either.

paulsherwin · 17th Jan 2007, 1:09 pm

Hi Brenda. Could you post a picture?

Ekco numbered their sets sequentially, so it will come between the A160 and A222 / A239 on Paul's disks. The A160 and A239 are cosmetically similar being big woodies, the A222 is a clock radio. The A160 is SW/MW/LW using 'U' series B8A rimlocks and the A239 is VHF/MW/LW using 'E' series B9A novals. I would guess all these radios date from 1955/1956.

Ekco used similar circuits in most of their early 50s sets and they aren't difficult to work on without the right schematic. The wax caps are big yellow things and it's easy to read the voltage and value if you scrape a bit of crud off. Basically there were 2 variants, one with a live chassis using an autotransformer and 'U' series valves and the other with a fully isolated chassis and 'E' series valves.

Good luck, Paul

brenda · 17th Jan 2007, 1:56 pm

http://www.geocities.com/lectroncity/Ecko218.jpg

Sideband · 17th Jan 2007, 2:17 pm

That could be a non-UK set judging by the number of wavebands it has. May make finding a diagram a bit more difficult.

Rich

paulsherwin · 17th Jan 2007, 2:30 pm

Strewth, good luck with that one, you'll need it

It may be related to the the A160 but is obviously not identical: http://www.vintage-radio-resources.com/ekcoa160.htm

If it's an export only model then it's not surprising there's no service data in the usual UK sources. It's very rare for a UK domestic radio to have so many SW bands, and it almost always indicates an export set. They usually have the same 4 valve plus rectifier designs as the UK versions.

The cabinet has some similarities to the A277, but that's an FM only set: http://www.richardsradios.co.uk/ekcoa277.html

Paul

brenda · 17th Jan 2007, 2:46 pm

http://www.geocities.com/lectroncity/Ecko218chassis.jpg

brenda · 17th Jan 2007, 2:48 pm

As you can see, it's a fairly complex chassis. It has 7 valves, including an interesting little eye tube. It also seems to have a VHF band of some sort, though I can't tell it from the dial glass.

brenda · 17th Jan 2007, 2:49 pm

It also seems to have an interesting power supply setup. The transformer doesn't appear to be an autotransformer, but the heaters do seem to be in series.

paulsherwin · 17th Jan 2007, 3:00 pm

I'd be very surprised if that set has VHF. FM started in the UK in 1956 and I don't know of any FM sets that use those B8A rimlock valves. More likely it's got an RF amplifier stage. If so the lineup will be something like UF41, UCH42, UF41, UBC41, UL41, UY41. The tuning indicator is almost certainly a DM70/DM71.

Some Ekco sets of that period did use a fully isolated transformer but series heaters, the only manufacturer I know of that did this.

It's an interesting set and a pity it's in such poor condition. If I were you I'd try to remove the tuning scale as carefully as possible and immediately scan it without cleaning, then clean the worst of the filth off and scan it again. You'll probably need to make a new scale with two pieces of picture glass and an inkjet printed transparency.

Paul

Sideband · 17th Jan 2007, 3:08 pm

Notice the two-pin mains plug so it is definately continental.

Brenda. That tuning indicator looks like a DM70.

Rich.

Paul Stenning · 17th Jan 2007, 5:25 pm

Quote:

Originally Posted by Richard_Newman

Notice the two-pin mains plug so it is definately continental.

That looks like a modern moulded plug and lead though, not original.

paulsherwin · 17th Jan 2007, 5:34 pm

Quote:

Originally Posted by Paul Stenning

That looks like a modern moulded plug and lead though, not original.

If it's in Seoul it's probably been there since the British Army was fighting in the Korean War, so you wouldn't expect to find a UK BS1363 plug on it

Paul

newlite4 · 17th Jan 2007, 5:36 pm

Brenda, that scale looks a nightmare

. I see that all four control knobs pass through it via large holes. If you were able to scan the remains of the existing scale and touch-up the missing graphics

, you could use perspex sheet which would be easier to drill holes into. Phew! looks like a tough one!
Neil

paulsherwin · 17th Jan 2007, 5:44 pm

A good glass merchant or picture framer should be able to drill the holes, but it won't be an easy job and is one for the professionals. Some sort of plexiglass would certainly be easier.

It seems very unlikely that a replacement scale or even a good scan will be forthcoming for this set, but it's amazing what can be done with image editing software.

Paul

jjl · 17th Jan 2007, 6:14 pm

Quote:

Originally Posted by paulsherwin

More likely it's got an RF amplifier stage.

It appears to have a 3 gang tuning capacitor, if so it's almost certain that it has a RF amp stage. The RF amp is probably an EF41 by the looks of things and is most likely to be one of the 2 valves next to the stacks of coils.
It should be a good set if you can get it going Brenda, but it looks like it will take up quite a few of your evenings and weekends.

John

Paul Stenning · 17th Jan 2007, 7:51 pm

Quote:

Originally Posted by Richard_Newman

Notice the two-pin mains plug so it is definately continental.

Quote:

Originally Posted by Paul Stenning

That looks like a modern moulded plug and lead though, not original.

Quote:

Originally Posted by paulsherwin

If it's in Seoul it's probably been there since the British Army was fighting in the Korean War, so you wouldn't expect to find a UK BS1363 plug on it

The point I was trying to make is that since the cable is not original, it can't be used as a guide to the origin of the set.

When I was in South Korea several years ago they used continental plugs like that for 230V and USA type plugs for 115V. So it is likely that the cable was fitted there at some point in the set's history.

brenda · 17th Jan 2007, 9:06 pm

I'm pretty sure that the set came from Myanmar (Burma). I have a friend here that makes trips there fairly frequently and comes back with British and Japanese sets from the 40's and mostly 50's. The old Burmese plugs look much like the current Korean ones, with the thick pins, but the spacing was different, a bit closer together. I'm certain the current cordset is a semi-modern Korean one that my friend has installed to the radio.

The thing that indicates a VHF band to me (perhaps it's used on one of the higher SW bands) is the extra three sections on the tuner. Note the sets of widely spaced plates on the tuner just back of the main sets. Usually these would be used only in VHF sets, or on separate tuners for bandspread.

I have found what appears may be a similar set schematic for an A239, though it seems to use noval valves.

I can get audio on the set, but with a lot of hum. The mains filters seem to be OK, with the hum coming from wiring that's not been reconnected right in some former repair attempt.

I get no LO at all.

Yes, it will be a challenging project, for certain.

paulsherwin · 17th Jan 2007, 9:36 pm

Quote:

Originally Posted by brenda

The thing that indicates a VHF band to me (perhaps it's used on one of the higher SW bands) is the extra three sections on the tuner. Note the sets of widely spaced plates on the tuner just back of the main sets. Usually these would be used only in VHF sets, or on separate tuners for bandspread.

I have found what appears may be a similar set schematic for an A239, though it seems to use noval valves.

I think the small tuning cap sections are for SW bandspread. This set looks as if it has sections for the different SW BC bands - 19M, 25M, 31M etc. All the early Ekco FM sets I know were permeability tuned, though they started to use capacitor tuning in the late 50s. The B8A valves point to the first half of the 50s.

The A239 is likely to be a red herring - it is a VHF/MW/LW set using 6.3V noval valves. I think that, if you forget about all the SW coils, the RF preamp and the tuning indicator, the circuit will be very like the A160.

DM70 tuning indicators are directly heated valves with 1.4V filaments originally designed for use in battery portables. They typically take their filament voltage from the output valve cathode. This has a tendency to rise in old radios as a result of a number of fault conditions, blowing the filament. They're still quite easy to find though aren't very impressive.

As John says, it's likely to perform well if you can sort the problems out. Change the UL41 grid coupling cap immediately if it hasn't been done yet, and check the current going through the UL41 cathode resistor.

Paul

stephanie · 23rd Aug 2007, 10:22 pm

Quote:

Originally Posted by brenda

The old Burmese plugs look much like the current Korean ones, with the thick pins, but the spacing was different, a bit closer together. I'm certain the current cordset is a semi-modern Korean one that my friend has installed to the radio.

The old Burmese plugs were two-pin 5 amp British plugs (BS 546 types) - I have one lying around the house (made by National in Burma).

Korean plugs are Schuko and Europlug types, the pins are just spaced every-so-slightly-different (enough that they won't fit without considerable FORCE in old two-pin 5 amp Burmese sockets and vice versa).

The cordset on your radio is Korean, Brenda -- most definitely either installed by your friend or whoever he bought the set from. I think I sneaked a peek at it one day and just remember from the size and shape of the pins, not to mention the lettering on the cord. *shrug*

17th Jan 2007, 9:45 am	#1
brenda Retired Dormant Member Join Date: Feb 2006 Location: Seoul, R.O.K. Posts: 26	Need schematic for Ekco A218 Just got all your service disks, Paul. Figures that the first radio I try to find in it isn't there. Murphy's Law. If anyone has a schematic for this radio, it would be greatly appreciated. Will also need a dial glass, if I ever get it working. TIA Brenda Ann

17th Jan 2007, 10:17 am	#2
Dave Moll Dekatron Join Date: Feb 2005 Location: West Cumbria (CA13), UK Posts: 6,127	Re: Need schematic for Ecko A218 It doesn't appear to be in R&TVS either. __________________ Mending is better than Ending (cf Brave New World by Aldous Huxley)

17th Jan 2007, 1:09 pm	#3
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,944	Re: Need schematic for Ecko A218 Hi Brenda. Could you post a picture? Ekco numbered their sets sequentially, so it will come between the A160 and A222 / A239 on Paul's disks. The A160 and A239 are cosmetically similar being big woodies, the A222 is a clock radio. The A160 is SW/MW/LW using 'U' series B8A rimlocks and the A239 is VHF/MW/LW using 'E' series B9A novals. I would guess all these radios date from 1955/1956. Ekco used similar circuits in most of their early 50s sets and they aren't difficult to work on without the right schematic. The wax caps are big yellow things and it's easy to read the voltage and value if you scrape a bit of crud off. Basically there were 2 variants, one with a live chassis using an autotransformer and 'U' series valves and the other with a fully isolated chassis and 'E' series valves. Good luck, Paul

17th Jan 2007, 1:56 pm	#4
brenda Retired Dormant Member Join Date: Feb 2006 Location: Seoul, R.O.K. Posts: 26	Re: Need schematic for Ecko A218 http://www.geocities.com/lectroncity/Ecko218.jpg

17th Jan 2007, 2:17 pm	#5
Sideband Dekatron Join Date: Oct 2003 Location: Croydon, Surrey, UK. Posts: 7,571	Re: Need schematic for Ecko A218 That could be a non-UK set judging by the number of wavebands it has. May make finding a diagram a bit more difficult. Rich __________________ There are lots of brilliant keyboard players and then there is Rick Wakeman.....

17th Jan 2007, 2:30 pm	#6
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,944	Re: Need schematic for Ecko A218 Strewth, good luck with that one, you'll need it It may be related to the the A160 but is obviously not identical: http://www.vintage-radio-resources.com/ekcoa160.htm If it's an export only model then it's not surprising there's no service data in the usual UK sources. It's very rare for a UK domestic radio to have so many SW bands, and it almost always indicates an export set. They usually have the same 4 valve plus rectifier designs as the UK versions. The cabinet has some similarities to the A277, but that's an FM only set: http://www.richardsradios.co.uk/ekcoa277.html Paul

17th Jan 2007, 2:46 pm	#7
brenda Retired Dormant Member Join Date: Feb 2006 Location: Seoul, R.O.K. Posts: 26	Re: Need schematic for Ecko A218 http://www.geocities.com/lectroncity/Ecko218chassis.jpg

17th Jan 2007, 2:48 pm	#8
brenda Retired Dormant Member Join Date: Feb 2006 Location: Seoul, R.O.K. Posts: 26	Re: Need schematic for Ecko A218 As you can see, it's a fairly complex chassis. It has 7 valves, including an interesting little eye tube. It also seems to have a VHF band of some sort, though I can't tell it from the dial glass.

17th Jan 2007, 2:49 pm	#9
brenda Retired Dormant Member Join Date: Feb 2006 Location: Seoul, R.O.K. Posts: 26	Re: Need schematic for Ecko A218 It also seems to have an interesting power supply setup. The transformer doesn't appear to be an autotransformer, but the heaters do seem to be in series.

17th Jan 2007, 3:00 pm	#10
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,944	Re: Need schematic for Ecko A218 I'd be very surprised if that set has VHF. FM started in the UK in 1956 and I don't know of any FM sets that use those B8A rimlock valves. More likely it's got an RF amplifier stage. If so the lineup will be something like UF41, UCH42, UF41, UBC41, UL41, UY41. The tuning indicator is almost certainly a DM70/DM71. Some Ekco sets of that period did use a fully isolated transformer but series heaters, the only manufacturer I know of that did this. It's an interesting set and a pity it's in such poor condition. If I were you I'd try to remove the tuning scale as carefully as possible and immediately scan it without cleaning, then clean the worst of the filth off and scan it again. You'll probably need to make a new scale with two pieces of picture glass and an inkjet printed transparency. Paul

17th Jan 2007, 3:08 pm	#11
Sideband Dekatron Join Date: Oct 2003 Location: Croydon, Surrey, UK. Posts: 7,571	Re: Need schematic for Ecko A218 Notice the two-pin mains plug so it is definately continental. Brenda. That tuning indicator looks like a DM70. Rich. __________________ There are lots of brilliant keyboard players and then there is Rick Wakeman.....

17th Jan 2007, 5:36 pm	#14
newlite4 Octode Join Date: Nov 2003 Location: Bath, Somerset, UK. Posts: 1,805	Re: Need schematic for Ecko A218 Brenda, that scale looks a nightmare . I see that all four control knobs pass through it via large holes. If you were able to scan the remains of the existing scale and touch-up the missing graphics , you could use perspex sheet which would be easier to drill holes into. Phew! looks like a tough one! Neil

17th Jan 2007, 5:44 pm	#15
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,944	Re: Need schematic for Ecko A218 A good glass merchant or picture framer should be able to drill the holes, but it won't be an easy job and is one for the professionals. Some sort of plexiglass would certainly be easier. It seems very unlikely that a replacement scale or even a good scan will be forthcoming for this set, but it's amazing what can be done with image editing software. Paul

17th Jan 2007, 9:06 pm	#18
brenda Retired Dormant Member Join Date: Feb 2006 Location: Seoul, R.O.K. Posts: 26	Re: Need schematic for Ecko A218 I'm pretty sure that the set came from Myanmar (Burma). I have a friend here that makes trips there fairly frequently and comes back with British and Japanese sets from the 40's and mostly 50's. The old Burmese plugs look much like the current Korean ones, with the thick pins, but the spacing was different, a bit closer together. I'm certain the current cordset is a semi-modern Korean one that my friend has installed to the radio. The thing that indicates a VHF band to me (perhaps it's used on one of the higher SW bands) is the extra three sections on the tuner. Note the sets of widely spaced plates on the tuner just back of the main sets. Usually these would be used only in VHF sets, or on separate tuners for bandspread. I have found what appears may be a similar set schematic for an A239, though it seems to use noval valves. I can get audio on the set, but with a lot of hum. The mains filters seem to be OK, with the hum coming from wiring that's not been reconnected right in some former repair attempt. I get no LO at all. Yes, it will be a challenging project, for certain.