Ekco A22 tuning drive re-stringing jig.

[David G4EBT]

When looking at the tuning drive cord layout in the service data, it couldn’t be simpler, except for three factors which complicate things. Namely:

1) The diagram shows the reverse of the two pulleys – not the front.

2) The upper pulley is attached to the tuning 'wand' to which the dial light wires are fixed, so unless you remove and refit the wiring, you have limited space in which to re-string the drive.

3) The pulleys can’t be re-strung in situ – they must be removed with the tuning wand attached, restrung and the cord kept under tension on the two pulleys while you turn them over and slip them onto the two ¼” shafts facing the speaker.

Well good luck with that!

Over the years, I’ve restored three A22s – two for my son, one for myself, which I recently needed to re-string. The only way I’ve ever managed to do it I with a simple jig onto which I can place the lower (tuning drive) pulley and the upper (tuning ‘wand’) pulley correctly spaced apart while I restring them, then to carefully slide them off the jig keeping the cord under tension, turn them over so that the dial cord faces towards the speaker, and place them on the upper and lower 1/4" shafts.

Hopefully, the pics will make this a bit clearer. The fourth pic shows the pulleys -re-strung on the jig - the fifth shows how the pulleys have to be turned over to face the speaker, and placed on the upper and lower 1/4" shafts while keeping the cord under tension.

The jig is just two offcuts of wood screwed together and two pieces of ¼” brass rod, pressed into 6mm diam holes in the wood, onto which the two pulleys are placed while they are re-strung. It takes less time to make the jig than it does to endure multiple failed attempts to do it by other means.

I hope that might help any fellow sufferers.

[kalee20]

Looks a useful item, built in a neat and workmanlike way!

I've never worked on on - but I can imagine it's the sort of thing that would have been used in the factory, when there's hundreds to be strung every week...

[60 oldjohn]

Originally Posted by kalee20

Looks a useful item, built in a neat and workmanlike way!

I've never worked on on - but I can imagine it's the sort of thing that would have been used in the factory, when there's hundreds to be strung every week...

Anything less would not be David, believe me!

Exactly what I was thinking, They would not have rows of girls stringing 3 or 4 radios a day each. I expect they would have maybe one girl stringing a radio in maybe 5 minutes, their fingers trained in a well performed "dance" routine, maybe using a Jig similar to David's.

John.

[stevehertz]

You're such a perfectionist David, I take my hat off to you, seriously. I'd probably use two four inch nails into a plank. But that's me!

[Lloyd 1985]

I like that jig! I can’t remember how I did my one, the original string had fallen apart.

Regards
Lloyd

[Panrock]

Impressive as ever.

Steve