An interesting old Coil

[pwdrive]

Post #36 would have made more sense if I'd attached the Booklet



Alan

Alan the article starting on page no: 27 in that link you posted could be something? A sort of early diversity reception idea.

Lawrence.

[Alan Douglas]

The November 1927 Modern Wireless has a lengthy article on a superhet using Peto-Scott split-primary coils. In some previous ads, "Copex" was applied to screening boxes, coil cans, and the six-pin sockets.

[AlanBeckett]

I can't say that I fully understood that Section Lawrence although I haven't really studied it yet.

Alan

[AlanBeckett]

And then there were three.
The attraction of this one was that it was by a different Manufacturer but with the same old Base.

   

The Knob on the top led me to believe that something might be adjustable but tis proved not to be the case.  It seems simply to be a means of pulling it out of the Base.
However, there is a Coil buried in there.

       

The Label on the top also reveales what LEWCOS means - THE LONDON ELECTRIC WIRE COMPANY AND SMITHS Ltd.

   

The Base is entirely different from the Formo one. However, helpfully it has the Connections moulded into the top and the Connections are numbered.

       

The actual Coil, which I suppose we'd call 'Medium Wave' is like this:-

   

So:-

That's three different Manufacturers of Coils and compatible Bases, so why are they (the Bases) so thin on the ground?
I was hoping to discover some compatibilitybetween the three but it's not obvious to me.
Assuming that this is the usual  'Aerial/Reaction' Coil which is which?

Come in Alan, you're the expert on tracking down ancient Adverts

Alan

[Alan Douglas]

Lewcos changed their Modern Wireless ad every month and this seems to be the first for these coils, January 1927:

[AlanBeckett]

Splendid bit of Detective work Alan.
It even has the Knob on the top and the usual 6 Pin Base although with a different Holder to mine. The Ad also quotes 'Split Secondary' and 'Split Primary' so that variety must have been reasonably popular.

Alan

[AlanBeckett]

And then there were 4. Not really as this one isn't 'Plug in'. The attraction was that it came with it's original Box and looked quite beautiful, although I don't think SWMBO will allow it on the proverbial Sideboard.

                           

The price equates to around £35 these days so you'd expect to get your money's worth, and indeed you do as it's enormous.
The soldering to the Tags underneath looks a bit scruffy and it's possible a couple of Wires have been moved - see below.

The Tags are labelled A, G, R, S1, S2 and S3.
Initially I took this to mean:-

A(erial)
G(rid)
R(eaction)
S(witch)1
S(witch)2
S(witch)3

However, the measurements may not bear that out.

The usual AVO Check revealed the following:-

   

Which boils down to:-

   

I really can't see how that would be connected.
The bit I don't understand is the end of the 'R' Winding which terminates on S3.
I assume that S1 is effectively a 'Ground' and also the Wiper of a two-way Switch. That would allow either S2 or S3, or both in Parallel, to be in circuit. So far so good for 'Long' amd 'Medium' Waves. However, if 'R' really is a 'Reaction' winding then S3 doesn't seem to be the right place to terminate it; S1 would be more logical. As it stands the Wire doesn't reach, and it comes out of the wrong hole, but of course it may have been buggered about with.

What does anyone think?

It looks as though the Software won't let me add any more Attachments so I'll continue in another Post.

Alan

[AlanBeckett]

So, to continue ...

There was a Tag in the Box but I'm unconvinced it belongs to the Coil.

       

It's not difficult to figure out what 'Wright & Weaire' became, but I can't find any connection to RI, or indeed much information about them at all.
Having said that 'Things' with RI on them turn up on ebay. Indeed I have a Choke.

       

So, who were RI and what happened to them?
Did they have any connection with W&W?

Alan

[Alan Douglas]

Radio Instruments had the back cover of Modern Wireless every month, but most of the ads are for audio transformers. None of my (few) loose issues up to 1930 show that coil, and my last bound volume is 1927.

I wonder why all the thumbnails display upside down or sideways when I click on them?

[AlanBeckett]

I wonder why all the thumbnails display upside down or sideways when I click on them?

So they do. Very odd. I'm not sure I can do anything about it. They were OK when I uploaded them.
Do any of the Experts know why?

Alan