Ekco A22 completely original, any refurb. tips, please.

[Scotorvm]

Hi guy's

Managed to source what looks like an A22 that's not been got at.

It works fine.

Apart from a good clean outside and in, would you touch this?

Replace caps? out of value resistors? or leave as the set is working?

Speaker fabric looks original just worn / aged, is this cloth available in a modern variety? or just leave as part of the character.

Any tips on how to remove the chassis without damage would be great.

Dial lamp is good all knobs rotate freely and work.

No cracks or chips anywhere.

The seller bought this second hand 51 years ago, still has part of the original flex. The set was playing well when I went to collect, sounded really loud and clear.

Thanks
Lee

[Herald1360]

Well, there's no specific "that" capacitor to worry about though the series combination of C32 and C30 could cause problems. At any rate check the dc volts on the output valve grid and its anode current.

Otherwise I'd say just a general clean up though original dust inside doesn't do much harm!

And keep a careful ear open for any output deterioration.

[stevehertz]

I'd take it apart and clean it thoroughly and maybe change that old flex if it looks dodgy. Then use it and listen for any deterioration or below par performance (compared to other sets) and take it from there with normal fault finding procedures.

[Scotorvm]

Originally Posted by Herald1360

Well, there's no specific "that" capacitor to worry about though the series combination of C32 and C30 could cause problems. At any rate check the dc volts on the output valve grid and its anode current.

Otherwise I'd say just a general clean up though original dust inside doesn't do much harm!

And keep a careful ear open for any output deterioration.

Thanks Chris, will check what you recommended.
Do you think the speaker cloth should be left as is, or should I be looking for a replacement

Cheers
Lee

[Scotorvm]

Originally Posted by stevehertz

I'd take it apart and clean it thoroughly and maybe change that old flex if it looks dodgy. Then use it and listen for any deterioration or below par performance (compared to other sets) and take it from there with normal fault finding procedures.

Cheers Steve, yes that old flex will have to go, in fact there is about a foot of original flex connected to modern pvc flex joined by twisting the copper strands and secured with insulating tape, they must have been using it like that for years. Had to be careful on the viewing as bare wiring was exposed.

Thanks.
Lee

[Heatercathodeshort]

Just give it a clean with a vacuum cleaner and a small paint brush. There are plenty of tarted up ones around and a rare example of an original one is nice.
It can easily be 'refurbished' but the reverse is impossible and it works! Just my thoughts. John.

[Scotorvm]

Originally Posted by Heatercathodeshort

Just give it a clean with a vacuum cleaner and a small paint brush. There are plenty of tarted up ones around and a rare example of an original one is nice.
It can easily be 'refurbished' but the reverse is impossible and it works! Just my thoughts. John.

Thanks John.

Yes that makes sense, didn't want to jump in and replace waxies left right and centre if the set is working. There is a bit of sellotape residue on the front left, was thinking just clean dust from inside and give the bakelite a wee buff. I have the appropriate cleaner.

I'm hoping to eventually have a cracking un-restored working set. These are lovely sets BTW, didn't realise how small they are

Cheers
Lee

[David G4EBT]

Firstly, much depends on your outlook. It will be evident from posts on this forum that views differ widely. Some will say 'I want to get this radio going', or 'I want to do it up a bit', or 'mend it'. Others will want to do a compete restoration. Some value cosmetic appearance and originality - even with commonplace radios - above all else.

Personally, if I'm not interested in fully restoring a radio, I don't bother with it.

If I do restore a radio, I adopt the following approach in order of priority:

1) Safety.
2) Functionality.
3) Originality.

So my comments are based on that ranking, which some may not concur with.

The A22 is probably the easiest radio on which to work and is a joy to restore as everything is so accessible.

Of all the radio I have, if I had to scale down my collection, the A22 would be the last to go.

A nice features is the 'backlash' slow-motion tuning.

I've restored three A22s - two for my son, and one for myself.

In each case, as received, none of them were safe to use - largely because the rubber insulation had perished and become brittle to a dangerous extent, including that in the wiring loom around the outer rim of the chassis. Some of the wiring only carries low Voltage - the 6.3V dial light for example, is run off a 5V tapping on the mains transformer (to keep the bulb cooler as it's housed in a little box on the tuning arm, and if left in one place of the dial would risk scorching the dial). But with every sweep of the tuning arm, the dial light wiring twists back and forth, so if it is brittle or perished, it's a simple task to replace it.

I replaced all of the waxy paper capacitors because from long experience, I know that they're invariably leaking in the electrical sense, and it takes no longer than it does to test them properly, (by lifting one end, checking the capacitance, and checking their leakage at the rated voltage with an insulation tester), which will almost certainly show that their capacitance has changed, and they are leaking to an unacceptable degree. They may not be dangerous - they're often in roles that have little voltage across them, but my view is that they're almost certainly likely to degrade the performance of the radio. Others may take a different view - that's fine.

If you haven't already downloaded the service data from the top RH of the page, I'd suggest that you do.

The Ekco datasheet is excellent, with very clear diagrams, but the Trader Sheet is also useful as it not only lists all of the components, it states what the role of each one is. That might be obvious to experienced restorers, but not to everyone. But do be aware that the Trader Sheet uses different numbering from the Maker's data, so if you do quote any numbers on the forum, always state whether it's from the Trader Sheet or the Ekco one.

Referring to the Ekco datasheet numbering, If you wanted to limit the extent of capacitor replacement, the very least I would suggest you do is to replace the tone correction capacitors, C36 (.04uF, use .047uF), and C32 (.0025, use .0022), the audio coupling capacitor C30 (.05uF, use .047uF), and V3 cathode bypass capacitor (25uF, 25V).

A modern 25uF capacitor will look puny compared the original, which is a small tubular one mounted vertically above the chassis. You could either disconnect the original one, leave it in place and mount the replacement one beneath the chassis (lots of room), or you could re-stuff the original one, which is what I did.

I have a capacitor reformer and in each case, the twin unit reservoir/smoothing capacitor reformed fine, progressively increasing the voltage as the leakage reduced until the rated voltage was reached. There was no trace of hum. Any problems, and a suitable 8/16uF replacement can be bought, or the original can can be re-stuffed, or could be disconnected, left in place and new ones wired beneath the chassis, depending on your approach.

I tested all the resistors and replaced any that were more than 10% out of spec. I used 2Watt metal film resistors as size wise, they look more compatible with the original ones.

One of the A22s I restored had clearly been owned by a heavy smoker as will be evident from the state of the speaker fabric. (I can't imagine what the state of his lungs was). I found a piece at the NVCF that was a reasonable match as a replacement. Two sources of fabric (both in the Netherlands) that you could try for something close to the original are:

Corrien Maas:

http://www.corrienmaas.nl/

(Corrien will weave new fabric to the design of the orinila, but wityh what lead time and at what cost, I couldn't say).

Ben Dijkman:

Homepage: https://www.bendijkman.nl/

A cloth called 'Pushbutton' looks a reasonable match:

https://www.bendijkman.nl/index.php?...oduct&ipath=14

Forum member Robert Darwent has probably restored more round Ekcos that most, and to a very high standard.

You might like to view his A22 restoration here:

https://www.vintage-radio.net/forum/...ad.php?t=45170

Pic 1: Before and after.
Pic 2: The component tag-strip.
Pic 3: The wiring loom.
Pic 4: Inside view.
Pic 5: Perished wiring.

I used silicone rubber insulated flex for rewiring, which is heatproof, strips easily, and is available in several vintage colours from forum meber Phl Marrison, SWB_18

Hope that of interest and help.

[Scotorvm]

Originally Posted by David G4EBT

Firstly, much depends on your outlook. It will be evident from posts on this forum that views differ widely. Some will say 'I want to get this radio going', or 'I want to do it up a bit', or 'mend it'. Others will want to do a compete restoration. Some value cosmetic appearance and originality - even with commonplace radios - above all else.

Personally, if I'm not interested in fully restoring a radio, I don't bother with it.

If I do restore a radio, I adopt the following approach in order of priority:

1) Safety.
2) Functionality.
3) Originality.

So my comments are based on that ranking, which some may not concur with.

The A22 is probably the easiest radio on which to work and is a joy to restore as everything is so accessible.

Of all the radio I have, if I had to scale down my collection, the A22 would be the last to go.

A nice features is the 'backlash' slow-motion tuning.

I've restored three A22s - two for my son, and one for myself.

In each case, as received, none of them were safe to use - largely because the rubber insulation had perished and become brittle to a dangerous extent, including that in the wiring loom around the outer rim of the chassis. Some of the wiring only carries low Voltage - the 6.3V dial light for example, is run off a 5V tapping on the mains transformer (to keep the bulb cooler as it's housed in a little box on the tuning arm, and if left in one place of the dial would risk scorching the dial). But with every sweep of the tuning arm, the dial light wiring twists back and forth, so if it is brittle or perished, it's a simple task to replace it.

I replaced all of the waxy paper capacitors because from long experience, I know that they're invariably leaking in the electrical sense, and it takes no longer than it does to test them properly, (by lifting one end, checking the capacitance, and checking their leakage at the rated voltage with an insulation tester), which will almost certainly show that their capacitance has changed, and they are leaking to an unacceptable degree. They may not be dangerous - they're often in roles that have little voltage across them, but my view is that they're almost certainly likely to degrade the performance of the radio. Others may take a different view - that's fine.

If you haven't already downloaded the service data from the top RH of the page, I'd suggest that you do.

The Ekco datasheet is excellent, with very clear diagrams, but the Trader Sheet is also useful as it not only lists all of the components, it states what the role of each one is. That might be obvious to experienced restorers, but not to everyone. But do be aware that the Trader Sheet uses different numbering from the Maker's data, so if you do quote any numbers on the forum, always state whether it's from the Trader Sheet or the Ekco one.

Referring to the Ekco datasheet numbering, If you wanted to limit the extent of capacitor replacement, the very least I would suggest you do is to replace the tone correction capacitors, C36 (.04uF, use .047uF), and C32 (.0025, use .0022), the audio coupling capacitor C30 (.05uF, use .047uF), and V3 cathode bypass capacitor (25uF, 25V).

A modern 25uF capacitor will look puny compared the original, which is a small tubular one mounted vertically above the chassis. You could either disconnect the original one, leave it in place and mount the replacement one beneath the chassis (lots of room), or you could re-stuff the original one, which is what I did.

I have a capacitor reformer and in each case, the twin unit reservoir/smoothing capacitor reformed fine, progressively increasing the voltage as the leakage reduced until the rated voltage was reached. There was no trace of hum. Any problems, and a suitable 8/16uF replacement can be bought, or the original can can be re-stuffed, or could be disconnected, left in place and new ones wired beneath the chassis, depending on your approach.

I tested all the resistors and replaced any that were more than 10% out of spec. I used 2Watt metal film resistors as size wise, they look more compatible with the original ones.

One of the A22s I restored had clearly been owned by a heavy smoker as will be evident from the state of the speaker fabric. (I can't imagine what the state of his lungs was). I found a piece at the NVCF that was a reasonable match as a replacement. Two sources of fabric (both in the Netherlands) that you could try for something close to the original are:

Corrien Maas:

http://www.corrienmaas.nl/

(Corrien will weave new fabric to the design of the orinila, but wityh what lead time and at what cost, I couldn't say).

Ben Dijkman:

Homepage: https://www.bendijkman.nl/

A cloth called 'Pushbutton' looks a reasonable match:

https://www.bendijkman.nl/index.php?...oduct&ipath=14

Forum member Robert Darwent has probably restored more round Ekcos that most, and to a very high standard.

You might like to view his A22 restoration here:

https://www.vintage-radio.net/forum/...ad.php?t=45170

Pic 1: Before and after.
Pic 2: The component tag-strip.
Pic 3: The wiring loom.
Pic 4: Inside view.
Pic 5: Perished wiring.

I used silicone rubber insulated flex for rewiring, which is heatproof, strips easily, and is available in several vintage colours from forum meber Phl Marrison, SWB_18

Hope that of interest and help.

Thanks David

That is a great comprehensive answer
I think you have covered all the items I had concerns about.

Will take me a while to digest this info.

I have removed the chassis from the case, already a piece of rubber insulation cracked, but I could probably leave as it isn't touching anything.

This is without doubt the first time this chassis has been out.

First thing is to remove all this dust and assess the situation from there.

Thanks so much for the links to speaker cloth, that's great

A few more pics attached.

Cheers
Lee

[David G4EBT]

That's the best condition in which to find any radio Lee - untouched by the 'phantom dabbler' who got there before you!

Every good wish with the restoration.

[Stuart R]

I dabbled....

I've told this story before. I carelessly used a flared-tip screw-driver to remove the chassis from my A22.

The wide end of the screwdriver caught one of the legs of the trimmers that sit along the bottom right-hand chassis screw. Now no shortwave reception.

Too lazy to dig out the right tool and that's the result. Go carefully with your good find.

SR

[Scotorvm]

Originally Posted by David G4EBT

That's the best condition in which to find any radio Lee - untouched by the 'phantom dabbler' who got there before you!

Every good wish with the restoration.

Thanks David, you're a true gent, will keep the forum updated with my progress.

[Scotorvm]

Originally Posted by Stuart R

I dabbled....

I've told this story before. I carelessly used a flared-tip screw-driver to remove the chassis from my A22.

The wide end of the screwdriver caught one of the legs of the trimmers that sit along the bottom right-hand chassis screw. Now no shortwave reception.

Too lazy to dig out the right tool and that's the result. Go carefully with your good find.

SR

Oh, first time i've heard this story Stuart, that must have hurt (you) not the radio , You just had me out in the shed double checking, as I used a long reach screwdriver and a torch to take out these chassis screws, I'm ok, no damage done, thanks for the heads up though.

Cheers
Lee

[Ian - G4JQT]

Nice sets and that one looks particularly lovely and undamaged. Although electronically they are unremarkable.

I've completely rebuilt three (but they were in a bit of a state), and if you search the forum you'll find discussions regarding some minor quirks/discrepancies between the circuit diagram and the actual sets.

I admit my approach might be considered as far too aggressive by some, ripping out their souls! When completed mine aligned exactly up to spec with an absolute sensitivity of between 2uV and 3uV on all bands. That's nearly as good as any modern AM communications receiver, although academic when noise is probably 10 to 20dB above that - unless you're very lucky!

I can't think of any particular concerns that have not already been mentioned.

Good luck.

[Scotorvm]

Originally Posted by Ian - G4JQT

Nice sets and that one looks particularly lovely and undamaged. Although electronically they are unremarkable.

I've completely rebuilt three (but they were in a bit of a state), and if you search the forum you'll find discussions regarding some minor quirks/discrepancies between the circuit diagram and the actual sets.

I admit my approach might be considered as far too aggressive by some, ripping out their souls! When completed mine aligned exactly up to spec with an absolute sensitivity of between 2uV and 3uV on all bands. That's nearly as good as any modern AM communications receiver, although academic when noise is probably 10 to 20dB above that - unless you're very lucky!

I can't think of any particular concerns that have not already been mentioned.

Good luck.

Thanks Ian, that restoration looks the business, way over my head re 2uV .. etc. Just hoping to have a set as original as possible while still being functional. This set is probably wasted on me, cost me a few bob, just love the look of it. Going to take this one nice and easy.

[Leon Crampin]

I'm the lucky owner of a black A22 which, as pointed out performs better than one might expect from a short superhet.

I'll add a few observations based on my own work and others' experience.

Be very gentle putting this set down. The shell around the "feet" is very thin and will not take any excessive load. Many broken sets show damage here.

The mains transformer is a known weak point - the HT secondary often goes o/c. Given the winding resistances quoted, it must be wound with really thin wire. There's not a lot you can do - but I wire a 1N4007 diode in series with each rectifier anode and put a 1A fuse in the plug to lessen any risks.

Watch the condition of the rubber covered wire to the dial lamp - it flexes a lot and is best renewed. I used thin stranded black silicone to avoid any refections. Finally, the dial if original is very brittle. Don't pick the set up when face down by putting your fingers under it...

Leon.

Beware the "too long" EBL31 problem (rebased EBL1s).

[Scotorvm]

Originally Posted by Leon Crampin

I'm the lucky owner of a black A22 which, as pointed out performs better than one might expect from a short superhet.

I'll add a few observations based on my own work and others' experience.

Be very gentle putting this set down. The shell around the "feet" is very thin and will not take any excessive load. Many broken sets show damage here.

The mains transformer is a known weak point - the HT secondary often goes o/c. Given the winding resistances quoted, it must be wound with really thin wire. There's not a lot you can do - but I wire a 1N4007 diode in series with each rectifier anode and put a 1A fuse in the plug to lessen any risks.

Watch the condition of the rubber covered wire to the dial lamp - it flexes a lot and is best renewed. I used thin stranded black silicone to avoid any refections. Finally, the dial if original is very brittle. Don't pick the set up when face down by putting your fingers under it...

Leon.

Beware the "too long" EBL31 problem (rebased EBL1s).

Thanks Leon, appreciate the advice and tips, especially from someone who has been there. Going to be really careful now, this set is my most expensive to date, don't want to spoil it.

Cheers
Lee

[Scotorvm]

Guy's

I'm progressing quite well with the restoration, all dust removed.
The back of the dial plate cleaned very carefully, even then I probably should have left well alone.

As per David's reply I have purchased hand woven speaker fabric from Corrien Maas (Cornelia van der Cammen).

Very nice, arrived today, £21 with a discount, she is closing her site by year end and concentrating on weaving for leisure, may be worth getting in there if you are in the market for in stock cloth.

While cleaning the set I did notice a 1.5" hair line crack in one of the feet. Is there anyway to stabilise against this becoming worse?

I have purchased 1.5mm clear silicone sheet self adhesive, my idea to put under both feet to provide cushioning and to stop the set sliding.

I was thinking of placing something in the hollow section of foot to stabilise the crack, any ideas on what would be the best material to use?

Cheers
Lee

[Radio tirana]

Hi Lee,
That cloth looks a fantastic match for the original, you can reinforce the case using glass fibre mat and resin on the inside. Originally the feet had felt underneath but the silicone sounds like a good idea.
Kind Regards RT

[Scotorvm]

Thanks RT

Yes for the money paid it is a quality fabric, closely matched to the original, which I will keep.

Great idea re the glass fibre mat / resin. Will order some of this. Thanks.

Lee