Bringing back the Springiness....

[G6Tanuki]

I recently acquired a new-old-stock [complete with Military packaging saying it had been at the Donnington stores depot in 1967] two-way-radio handset.

The curly-cable had lost its springiness - see the first photo - showing how it really didn't coil up tightly like it should.

OK, after five decades it could be expected to be a bit 'relaxed'.

So I 'reverse coiled' it, and it's now wound round a piece of suitably-sized dowel [actually the handle of a wooden spoon] and I am giving it regular heat-treatments with a hairdryer.

Will this work? Or will it try to revert to its originally-coiled sense if it gets stretched?

[ajgriff]

I've always resurrected these by dropping them in boiling water for a few minutes. Returns them to their 'new' state.

Alan

[Nickthedentist]

This is a common problem with old telephone handset cords too.

Your method is recommended for sorting out cords which have been mistreated and kinked. But I fear it may not work in your case. No harm in trying though.

[G6Tanuki]

Thanks for the suggestions and warnings of no guaranteed success.

I will continue with the hairdryer treatment for a few weeks and then uncoil it to see what has developed.

In times past I would have just sourced a replacement curly cord from A.P.Besson or Airlite or RACAL. Sadly that is not an option today.

[GMB]

Let's hope it doesn't end up suffering from a very annoying problem I have encountered with original NOS similar items, namely the outer covering of the cable cracks (in spite of not being brittle) in many places and it all falls apart except for the inner wires.

I should just add that this strange problem seems to occur quite soon after being unwrapped from its original packaging, so must be to do with exposure to the air for the first time in decades.

[elanman99]

I would say that soaking in an oven for an hour or two (say at 120-160C) would have a better chance than the heat gun/hairdryer method.

I'm not sure either will be successful as some cables were made with what spring manufacturers call 'initial tension' where the finished spring is shorter than it wants to be!

(the coils are already pressed against each other)

Ian

[pip5678]

As in #2 - a kettle of boiling water with the cord wrapped round a dowel and, avoiding getting scalded of course, 'tighten' the coil back up. It has always worked for me.

[G6Tanuki]

I have come across the thing where a NOS curly lead crumbles after being unpacked a few times before, with Clansman audio gear. Still, it was ten years after Clansman had been withdrawn from service so perhaps I was expecting a bit much.

Am worried about applying too much heat to the curly lead, putting it in the oven would be a bad idea as it might melt the Nylon handset.

The hairdryer treatment continues.

[ajgriff]

Originally Posted by pip5678

As in #2 - a kettle of boiling water with the cord wrapped round a dowel and, avoiding getting scalded of course, 'tighten' the coil back up. It has always worked for me.

I'm glad someone else has used the boiling water trick although I've never found it necessary to wrap the cord around a dowel. Must have boiled a dozen or more cords without a single failure. Best to disconnect the cord from the handset though. I'm sure I first came across this method described on one of the vintage telephone sites but that was a good few years ago.

Alan

[G6Tanuki]

Pleased to report that my 5-times-a-day hairdryer-therapy has seemingly produced the required result; even when letting the handset dangle free and unsupported on the curly-cable, it then coiled back up in the required sense and didn't show any signs of wanting to do a reverse-twist (which was always a big issue with both Post-Office/BT cordsets once they'd got reversed, and the Siemens cordsets I had to endure on a bunch of contracts in the 90s).

Now, next thing - to source a dynamic/moving-coil mic to replace the carbon-type in this 1960s handset!

[Nickthedentist]

Well done, I’m impressed!

[G6Tanuki]

Originally Posted by Nickthedentist

Well done, I’m impressed!

I'm happy, too!!

[Jon_G4MDC]

I'm sure I have one of those red mic inserts. I reckoned it was magnet+diaphragm type. Basically same as a Pye Westminster AM insert.
A.P Besson.

[G6Tanuki]

It may be a dynamic / moving coil mic; what has confused me is that the wiring to the 5-pin DIN plug is something other than that usually found with Pye gear.

Time to do some dismantling and tracing the colours of the wiring.

[Jon_G4MDC]

Yes, that is very possible. I'm sure you will only need to rewire it.
I had one of those handsets once upon a time. Not carbon...

[G6Tanuki]

Yes it is a moving coil insert. I have rewired the plug to the standard Pye schema, and it works just fine on a Westminster W15FM.

I wonder what it was originally intended for?? Someone in another place suggested that it could have been part of a Redifon HF system.

[Jon_G4MDC]

Pleased about that. Sorry I have no idea about the source of my one.

[Pellseinydd]

Originally Posted by G6Tanuki

Yes it is a moving coil insert. I have rewired the plug to the standard Pye schema, and it works just fine on a Westminster W15FM.

I wonder what it was originally intended for?? Someone in another place suggested that it could have been part of a Redifon HF system.

I remember them being used with the Army's 'Larkspur' range of radio equipment back in the 1960's with sets such as the small VHF A40 and backpack A41.sets

Ian J
then a very young R.Signals TA officer.

[ex seismic]

A40/41 were carbon microphones. Red insert with black stripe. White stripe was moving coil for C42/B47/C13 etc.

[dagskarlsen]

Looking good!
I hve used to coil the cord around a stick and fix it with a tiny wire in each end, putting it in the dishwasher and run it on a regular program, with soap, comes out clean and good. (only don this on plastic cords)