Ekco A239/1: A Sorry Tale.

[Joe]

Last night I decided to have a go at my Ekco A239/1.

The known issues are

It doesn't work on VHF, it may as well be on 'Gram' for the sound it makes.
The magic Eye doesn't work
After being on for about ten minutes it starts to get quieter

My first priority was THAT capacitor and that was where I came unstuck. It a metal tube with one black and one red end but isn't shown as electrolytic on the diagram so I'm assuming this means nothing more than the black band on a waxie. However what's completely foxed me is its having a connection to it's case which, again, isn't shown on the schematic.

Any advise appreciated.

- Joe

EDIT - Advise was received that these are 'MetalMite' capacitors which are non-polerised and should be changed as they would odds-on be leaky.

[tiv48]

agree i am begining to find Metalmites leaking also bumbel bee ones the only ones i trust are phillips/mullard mustard a polyester will be fine in that position
rob t

[Joe]

Thanks for the answers. Now I'm working in natural light (though not much as it's raining) I can see that that third connected is just a screening contact to the chassis so I can get on with it as I've already got the caps but was just unsure how to connect them.

Thanks, chaps

- Joe

[Joe]

I've done a bit as it's a total pig to work on.

I changed C61 (Ekco schematic) which is THAT one, C68 and C57. The latter is something to do with the tuning inicator. This still isn't working but the heater is glowing.

I've had it playing my DAB for a couple of hours now with no problems. I don't know if C68 was leaking and pulling the HT down or what. On LW and MW it's fine but I have noticed on strong signals as well as the station it brings in a hum which isn't there between stations or on weaker ones - it's 'silent' on Gram.

The biggest issue is still VHF not working. The obvious thing is the band switch but that seems pretty good with no excess crackle when it's operated. I'm going to treat myself to some proper switch cleaner so will give it a blast with that when I do. For the last twenty-odd years I've used WD40 with no problems but now I'm working on decent equipment it deserves the proper stuff.

Lack of VHF isn't too great a problem as I can plug my DAB or phone into it but, obviously, it would be nice if it did work. I'm loath to start any mass re-capping exercises but if anybody can suggest specific ones to change I'm quite game. Failing that it's usable like it is and sounds great, though it's playing through my bench speaker so may be different on its own, so I would mind leaving it 'til I've got a better idea of what I'm doing.

Thanks for the help so far.
- Joe

[Joe]

The MetalMite I took out didn't seem too bad post mortem but there must have been something up with it for the radio to suddenly get so much better; it was next to useless yesterday but fantastic today. I will give the rest the benefit of the doubt - for now. I've got plenty of my little orange chums if they're needed!

Cheers
- Joe

[Joe]

Next question: C79 is an old waxie but is rated at 600vAC and I was wondering if it needs to be.
   
Thanks
Joe

[Mark R]

That is the tone corrector cap on the HT side, so it needs to be 450v dc working at a guess. on the trader sheet 0.005uf.

cheers Mark

[Joe]

The old one is definitely 0.0025µF 600VAC. I agree about the voltage bit; it's the fact it's AC I couldn't understand.

Cheers
- Joe

[Mark R]

AC voltage rating is always higher than DC voltage rating, so it is probably just a component they had to hand.

cheers Mark

[Joe]

That could well be it, Mark. It was 0.005µF in the A329 but this is the A329/1. Sadly the Ekco data sheet doesn't quote the voltages, or resistor powers come to that.