Restoration of braided flexible cable, circa 1925 (Low Voltage!)

That's going back a bit Clive. Is the lead (BBC term) made with a dark red/purple cotton braid coat over the rubber insulated cable? Your best bet would probably washing powder and water with a gentle nail brush, but it is old enough to be fairly "crinkly" as they say of us oldies! The cores are almost certainly tinsel conductors, but the rubber layer is not quite that which I expect, it used to be DCC leads and then the red overcoat from memory. Good luck.

I have had some success with massaging in a little shampoo where the contamination is finger grease tobacco and so on, then rinse with clean water and a very slow dry.

be gentle, the tinsel cable cores are really hard to solder to if you snap the ends.

I'd like to think they are ELV rather than LV, but I have been shocked (in both senses) to find that on an HRO I was restoring a good few years back the headphone terminals connected directly between the output valve anode and the HT+ . (the terminal voltage being accessible as exposed 6BA bolts on the High Z headphones I was using at the time)   Some versions of the circuit showed an output transformer to drive low Z phones or a speaker, that one did not. Wartime design and production control was clearly a bit more liberal than we would allow today.

Take care if you are ever moving into more modern stuff and doing that sort of thing.

The lead is of twisted construction and is dark brown and greenish in colour. My comment re rubber insulation is very much a guess on my part, but the lead has a rubbery feel when squeezed.


Years back when connecting a similar sort of flex to a jack plug, I successfully terminated the tinsel style inner by wrapping it in fine fuse wire in a similar way that headphones with external terminals have the conductor shaped as an eye.


Also, the black bakelite ear pieces have defied both mine and my wife's attempts to remove.  A WD-40 soak and a silicone rubber jar top remover will, I hope, do the trick.


The above may be a few days off, since in the morning I am off for a bilateral selective laser trabeculoplasty to bring my IOCs within range. I tend to "run" with a high IOC but fortunately have no signs of glaucoma. Drops have been tried and stung like hell (the preservative apparently). After putting up with the discomfort for too long the opthalmologist I see said stop the drops and I will see you in a few weeks. Went back and pressures exactly the same.....

Clive

Having just looked up what that is, my thoughts are with you for that one, and I hope it goes smoothly for you today. I do not think you will want to do anything requiring close vision immediately after.

Thanks Mike, better than I expected in fact.

I had 90 zaps in each eye. Just a green flash and a click for each zap, no discomfort or pain at all during the procedure.  As expected, the drops to close my pupils caused a headache, within ten minutes of them going in.


During my 25 years in the MN, I didn't see many green flashes https://en.wikipedia.org/wiki/Green_flash I certainly made up for it this morning!


Now to soak some WD-40 into those earphone threads!

Clive

Glad that it was all successful, Clive.  My daughter had the same treatment a year or so ago - completely satisfactory.


Isn't the "click" inside your head weird?


David

Hi David

Well, you have got me thinking now. To me the "click" was from the equipment, never for one moment thought that it was "internal". I am seeing the Consultant Ophthalmologist in six weeks time, so will ask whether he heard it too.  Pleased to hear that your daughter's treatment went well.


I have experienced other "internal hearing" phenomena. About 1976 I visited the Decca Navigator Radio Station at Neston, Wirral. This used to transmit mainly on 70.5375 kHz, it being the Green Slave; but the nominally continuous wave transmission were in fact divided into a 20-second cycle, with each station in turn simultaneously transmitting all four Decca frequencies (5f, 6f, 8f and 9f) in a phase-coherent relationship for a brief period of 0.45 seconds each cycle.it also transmitting during its cycle on, in the case of Neston 84.645 kHz, 112.86 kHz, 115.6815 kHz and 126.9675 kHz as well, there additionally being a 8.2f as well)


We were invited into the Aerial Tuning Unit hut at the base of the "Tee" aerial and you could feel the keying sequence as a sensation. Then some years later when using my GSM phone in my cabin (a steel box with a couple of windows) I could feel the GSM keying just above my ear, same cadence as when in an aircraft and as you approach a country from an over sea route you can hear the GSM phones making contact as audio interference on the PA system.

Clive

Hi Clive,

I did not have the same procedure as yourself, but another type of laser treatment following cataract surgery, my clicks were definitely internal. My daughter had the same procedure as yourself and had a similar experience to me.  I will be interested what your consultant says.

Your tales of hearing transmitters triggered a memory of when in my much younger days I worked at Rugby on the GBR 16 kHz transmitter.  My young ears could hear the transmission, although I suspect that it was various bits of equipment vibrating with the carrier rather than hearing the R.F.
Scrabbling around in the aerial loft was an eye opener, huge aerial tuning capacitors and coils, interconnectors of litz wire 2 or 3 inches diameter, that despite their size were very flexible.  I was there measuring the radiation resistance after some changes to the capacity top to the aerial, and was astonished to find that when terminated, the Droitwich 200 kHz transmitter put half an amp down the GBR aerial.


David

Is something new like this suitable to replace the existing :
https://www.creative-cables.co.uk/2262-lighting-cables#/style-twisted

I am afraid that none of them look at all like the original.