Eddystone 888A.

[Wendymott]

Well peeps. Im back from my "jollies" to a load of comments from you all, much appreciated. Job one remove the spiders and webs, as I said in my opening message, I have restored my 750, and I reasonably know what to expect. I will add more "finds" when I get to them, but noted from Al (Skywave) about padding caps. I bought a "few" ECH81's from a guy last year, never used them and I was considering replacing the ECH42's with them. I bought a couple of 1.535 Mhz crystals, so one of them may be used in the I.F Converter. I am NOT interested in keeping it as a museum piece, if it works well, so be it.

[Wendymott]

Hi peeps, a question. I have stripped down the front panel for "bead blasting" and painting, however the dial drive cord, was it originally waxed string or steel wire? I am not opening my 750 to see. All the screws on the front panel were "not tight" in fact some were quite loose, and some knob grub screws were totally seized, thus drilling out was the only solution. Those dots on the 20 metre dial, are round headed pins, the backs of which interfere with the rotating graduated dial disc, and thus will be removed. I am thinking of making a dial overlay, using the original dimensions in Paintshop pro. Spiders evicted.

[Skywave]

For the 888 and the 888A, the drive 'cord' is wire. To the best of my knowledge, all the Eddystone receivers with the wide, rectangular glass screen used wire for the tuning mechanism. It is quite common to find the scale pointer soldered to that wire.

Al.

[Wendymott]

I thought so....some one had repaired with wax dial drive cord....tightened up the tensioner so it did not work. Now where do I source some dial drive wire from ??
My EC10 has dial cord.......

[HamishBoxer]

This is a big guess,would piano wire be any good?

[Radio Wrangler]

I think the original was several strands of fine wire to make it more flexible going round pulleys and winding onto/off of the screw-threaded drums at the ends. It was a brassy colour, and as said it would take solder.

David

[Wendymott]

Hi Hamish. No its got to be stranded.....as David says.. to be pliant enough..... I remember years ago, a certain Philips domestic radio having "piano wire" and another type of wire, I think it was an AM/ FM receiver... and it was neigh impossible to re string. The piano wire kept jumping off its pulleys as you tried to lace the other.

[turretslug]

This sounds like a classic case where someone with a completely different hobby might come up with the perfect answer- and the vernacular that eases the search problem! I'm not claiming that myself, but I've heard mention of "tiger tails" (fine stranded jewellery wire) as a possible solution- it can be found in plentiful quantities for trivial prices (though actually fitting thin, taut stainless steel wire might not be trivial on the fingertips....), no doubt there are other possible candidates.

The pointer drive wire in my 750 is very fine indeed and its dark green, near black colour makes me suspect that it's brass- concerned that something like a green-spot failure mode could ensue, I gave it a good run-through smear with a bit of rag doused in one of the proprietary bicycle lubricants intended for cable inners that consists of a waxy, protective substance in a volatile solvent- it may not actually help, but at least I doubt that it does harm.

[turretslug]

Re. mods to the second conversion stage as mentioned in post #21, I've often thought that a +- 3kHz or so trimmer on the 750's 2nd LO would have been nice as a clarifier- though, of course, SSB transmissions didn't have the prominence at the time of design as they did subsequently. Eddystone considerably developed this theme subsequently, leading to 910 and 830 receivers, but with a much wider interpolation range.

[Alistair D]

What about something like this

http://www.ebay.co.uk/itm/Cousin-Jew...0AAOSwiwVWRW6n

The same type of wire is also available in 0.45mm.

I have no experience of using it myself. I came across it quite by accident while searching for something else.


EDIT: Something like these

http://www.ebay.co.uk/itm/14K-Gold-F...wAAOSw~bFWM-IF

may be useful for forming the end loops on the wire.

Al

[G4BZI Roger]

If you search the Forum for "pike wire", one of the posts has this information:

DRENNAN 7 STRAND PIKE WIRE 24LB 10.9KG Is a woven Stainless Steel wire & is the same size an type as used on Eddystone's. I have used a number of times to replace dial drive wires on Eddystone's. I bought it a local fishing shop. It was about £3 for 20M.

I have some ready to sort our my 888A drive cord - when the "round tuit" pile diminishes!!

Roger
G4BZI

[G6Tanuki]

As mentioned, stainless-steel fishing-lure wire is the stuff to go for. It doesn't stretch!

[Ed_Dinning]

Try Wires.co.uk They have all sorts of wires including stuff for jewellery.
Another possibility would be cycle Bowden cable (the thin one for the gears)

Ed

[carnivalpete]

>>wendymott
If you put ''Eddystone dial drive cord'' into the search box you will find I covered this cord supply topic when I overhauled my 888A
I regret it's not an easy job but it can be done.
best wishes, pete

[Wendymott]

Hi peeps. MANY MANY thanks for your contributions. I will call at the fishing tackle shop today. I did buy some other line for my EC10 from there, but ended up using some jewellery string.
The case is now at the Metal Finishers for bead blasting and powder coating.
The gear train will now be cleaned and lubricated.

[carnivalpete]

>>G4BZI Roger - Re: Eddystone 888A - dial drive wire.
''I have used a number of times to replace dial drive wires on Eddystone's.''

Been there, done that (once), as they say. But I couldn't find a way to solder the stuff as Eddystone had done. I had to use spots of araldite. Happily I don't have a re-stringing to do right now but I'd be most interested to know whether you mastered soldering to the end pins. cheers, pete

[G6Tanuki]

When I've restrung tuning-drives using braided stainless steel lure-line rather than soldering it I've used the inner brass barrel-things from 5-amp "choc-block" terminal strips. These have the advantage that you can unclamp and readjust them really easily. If space is limited you can cut down a barrel so it only has one screw.

Why people still mess around with 'string' when they can use stainless braided wire I can't understand.

[Wendymott]

Great Idea Tanuki... still waiting for the case to be painted.... tumm te tumm te tumm. Can't wait to start reassembly.

[G6Tanuki]

I'm following your rebuild with interest: the 888A (and its successor the EA12) were both receivers I lusted after in my early-1970s SWL days.

[Skywave]

Originally Posted by G6Tanuki

Why people still mess around with 'string' when they can use stainless braided wire I can't understand.

A common arrangement is to have a drum on the variable tuning capacitor connected to a typical quarter-inch shaft, to which the tuning knob is attached. I would have thought that using wire for that connection will reduce the frictional grip on that shaft, unlike using twine, which will produce a greater coefficient of friction. That friction is often enhanced by winding the twine several times around that shaft.

Al.