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Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
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24th Feb 2018, 12:59 pm | #1 |
Hexode
Join Date: Apr 2017
Location: Falkirk, Stirling, UK.
Posts: 336
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Ekco A21 Restoration
Hi all, I have just started on the restoration of my Ekco A21. These radios were kindly donated to me by a member of this forum some months ago but I have only just got round to starting them. One of the radios chassis has been scavenged for parts, all the valves, knobs and the front case plate were missing. The other is complete however has a cracked case, a simple case swap and I should have a complete and good looking A21. Upon inspection of the complete chassis everything looks good, it's very tidy and clean and must have been dusted out at some point I would imagine. No suspicious looking components. I gave it a quick blow out with my Hoover just to remove some more dust. I then went on to testing the resistance between the live and neutral and it comes in at 46 ohms. This seems very low I read it should be around 200. Any suggestions? I'm still new to all this it's only my second restoration if you don't count the other projects I have awaiting completion! I do have another transformer on the other chassis if it comes to replacement but I don't know if that one works either.
Cameron |
24th Feb 2018, 1:02 pm | #2 |
Moderator
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Re: Ekco A21 Restoration
The service sheet says that the total resistance of the primary winding is 45 ohms, so there's nothing to worry about on that score.
You do have a service sheet? If so which one? It will help when giving further advice.
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24th Feb 2018, 1:07 pm | #3 | |
Hexode
Join Date: Apr 2017
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Re: Ekco A21 Restoration
Quote:
Cameron |
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24th Feb 2018, 1:08 pm | #4 |
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Re: Ekco A21 Restoration
It's a short superhet. Suggest changing C28 and C30. Trader sheet.
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Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
24th Feb 2018, 1:12 pm | #5 |
Hexode
Join Date: Apr 2017
Location: Falkirk, Stirling, UK.
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Re: Ekco A21 Restoration
I'm glad I have finally figured out what 'that' capacitor is. I wasn't sure about c30 since it was after the coupling capacitor c28 but that makes sense. I'll hopefully get them both replaced shortly assuming I have the correct values.
Cameron |
24th Feb 2018, 1:25 pm | #6 |
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Re: Ekco A21 Restoration
There is no "that capacitor" in this set. It's a short superhet with no audio amplifier stage.
On reflection I'd leave C30 alone as it's only 39pF and unlikely to be faulty.
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Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
24th Feb 2018, 1:56 pm | #7 |
Hexode
Join Date: Apr 2017
Location: Falkirk, Stirling, UK.
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Re: Ekco A21 Restoration
Well it looks like someone has changed the capacitor before, I cut it out before realising. What type of capacitor is this? I'll put it back in if it will still be fine.
Cameron |
24th Feb 2018, 1:59 pm | #8 |
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Re: Ekco A21 Restoration
That's C28 0.02uF, not C30 39pF.
EDIT. Value apears to be 0.05uF, so either it's been replaced with the wrong value or it's not C28.
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Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
24th Feb 2018, 2:09 pm | #9 |
Hexode
Join Date: Apr 2017
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Re: Ekco A21 Restoration
Yes I'm sure someone has replaced it, am I right in saying that value should be fine? It is a sort of plastic material which makes me think it should still work but I'm not sure.
Cameron |
24th Feb 2018, 2:34 pm | #10 |
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Re: Ekco A21 Restoration
If it is C28, then personally I'd replace it with 0.022uF or 22nF.
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19th Mar 2018, 2:11 pm | #11 |
Hexode
Join Date: Apr 2017
Location: Falkirk, Stirling, UK.
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Re: Ekco A21 Restoration
Well I finally got round to putting in the new capacitor. I plugged it into my dim bulb tester and fired it up. It sounds fantastic and seems to work well on initial tests. Unfortunately the tuning cord snapped during testing so I'll need to replace that. I think I'll leave the rest of the capacitors for now since it sounds so good, no point messing with it if it works fine. I'll be replacing a few of the rubber wires that are in a bad way then I'll get the case cleaned up and put it in there.
Cameron |
19th Mar 2018, 10:41 pm | #12 |
Hexode
Join Date: Apr 2017
Location: Falkirk, Stirling, UK.
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Re: Ekco A21 Restoration
I spent the evening polishing up the case with brasso, I'm fairly happy with the results and it has a decent shine. Should I be putting some sort of wax over the top? I have attached a few pictures which aren't really very good, I tried using my new 1000W lamp but couldn't get a good picture due to reflections. I also installed new speaker wires, all the rest of them seem to be ok on inspection and cleaned the dust from the speaker and speaker cloth. Now I just need to do some research on what I should use to replace the tuning cord.
Cameron |
19th Mar 2018, 11:45 pm | #13 | |
Dekatron
Join Date: Nov 2006
Location: London, UK.
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Re: Ekco A21 Restoration
Quote:
I'd personally leave it with the polish. Some people like a 'factory gate' finish, as if it had been built yesterday. Others, like me, like it to look as it might have after being used in a domestic situation for a few years - shiny, but not too much. It's a matter of personal taste, no right or wrong! It looks great from here...
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Al |
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19th Mar 2018, 11:57 pm | #14 |
Hexode
Join Date: Apr 2017
Location: Falkirk, Stirling, UK.
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Re: Ekco A21 Restoration
Yes I tend to fall under the latter category, I like to see a bit of use on my items. I think I'll just leave it as is then, I'm quite happy with the shine I was just wondering if wax would protect the shine in some way to prevent it from going dull in future.
Cameron |
20th Mar 2018, 12:53 pm | #15 |
Hexode
Join Date: Apr 2017
Location: Falkirk, Stirling, UK.
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Re: Ekco A21 Restoration
I have just spent a few hours trying to restring the radio with some old kite string. Unfortunately the string keeps fraying at the end and I can't get it through all the small holes. It is a bit thinner than the original string too so I don't know if it would work even if I did get it string up, can anyone suggest a string replacement? I don't know the diameter as my calipers broke.
Cameron |
20th Mar 2018, 8:16 pm | #16 |
Hexode
Join Date: Apr 2017
Location: Falkirk, Stirling, UK.
Posts: 336
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Re: Ekco A21 Restoration
A bit more trial and error and I decided to superglue the ends of the string, seems like an obvious solution on reflection. I then strung it all up and it works well. I put everything back together and it looks good, I'm quite happy with the results and it sounds good too. I have attached some pictures of the completed restoration.
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