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 |
Re: Need schematic for Ecko A218
It doesn't appear to be in R&TVS either.
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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 |
Re: Need schematic for Ecko A218
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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 |
Re: Need schematic for Ecko A218
Strewth, good luck with that one, you'll need it :D
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 |
Re: Need schematic for Ecko A218
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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.
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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.
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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 |
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. |
Re: Need schematic for Ecko A218
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Re: Need schematic for Ecko A218
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Paul |
Re: Need schematic for Ecko A218
Brenda, that scale looks a nightmare 8-o. 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 :o, you could use perspex sheet which would be easier to drill holes into. Phew! looks like a tough one!
Neil |
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 |
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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 |
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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. |
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. |
Re: Need schematic for Ecko A218
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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 |
Re: Need schematic for Ecko A218
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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* |
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