PLUGS, Aerial, Single No. C1 (ZA/CAN 1480)

[David Dunlop]

This is the typical aerial plug fitted to the ends of the transmission lines attached to all the wartime wireless set horizontal aerials. It is also fitted to one end of numerous feeder and conductor cables for these sets to various whip aerials and mast assemblies. It is mounted to a No. 10 ring terminal by means of a 4BA x 3/8 inch, Cheese Head screw and internal toothed lock washer.

I have not yet been able to find the exact measurements for this plug that would allow them to be copied by a machine shop, and a problem, at least locally here in Canada is not many shops would carry BA tap and die sets in their inventory any more.

I would like to find several of these to fabricate various connector cables for my two 19-Sets. They must have been manufactured by the tens of thousands during the war and held in stores in large numbers. Somebody is probably sitting with a bin full on a shelf somewhere not knowing what they are.

If anyone can find the dimensional specs for this plug that would allow it to be cloned, can they post same?

David

[Chris Suslowicz]

It's just a turned brass plug to mimic the standard Aerial Rod 'F' base, with a knurled portion so you can extract it from the aerial base without pulling on the wire, and nickel plated overall.

I've got a set of those aerials so will fish them out and run a micrometer over them for you.

The only hard part will be getting them nickel plated, everything else is just standard turning on a lathe and tapping the hole for the screw.

Chris.

[David Dunlop]

Thanks, Chris.

David

[Bruce Parker (RIP)]

I may be guilty of having one or two of those on the shelf.

[David Dunlop]

Hello Bruce.

If you happen to run across them, would you consider selling one? Or do you know anyone locally in your area that could clone them?

David

[Grant Bowker]

Originally Posted by David Dunlop

It is mounted to a No. 10 ring terminal by means of a 4BA x 3/8 inch, Cheese Head screw and internal toothed lock washer.
.........at least locally here in Canada is not many shops would carry BA tap and die sets in their inventory any more.

Fully agreed that not many Canadian machine shops will regularly work in BA threads. Some BA threads are close to current metric threading, not perfect but "will fit". The ones I'm thinking of are a little off, loose so I wouldn't trust them for high torque but a much better fit than either coarse or fine SAE.

[David Dunlop]

Hi Grant.

My thought process is vintage British motorcycles and sports cars will still require machine shop work done from time to time.

On the down side, any such vintage owner, will very likely have picked up a small BA Tap and Die set years ago, at the very least to clean up and repair any damaged threads found on their vehicles themselves.

That being said, if a large enough pool of vintage British vehicle owners can be found in any given area, chances are a small machine shop could exist there, supporting that population.

As Chris noted, it is pretty simple lathe work (not that I have ever done any of that) and any lathe with a feed through capability could probably be used to cut three or four plugs at a time. Once separated they could then each be drilled and tapped accordingly.

And also on the bright side, if there is a large enough pool of vintage vehicles in an area, there is very likely a plating shop that could handle that part of the work as well.

There is another version of this type of plug I will do a separate post about shortly.

David

[Bruce Parker (RIP)]

BSF tap and dies sets are available quite easily. BSF is the same as 'NF' except the pitch of the threads is 55 degrees instead of 60.

[Grant Bowker]

https://maccmodels.co.uk/batometric
The link above is to a chart giving metric dimensions for BA threads. The "close BA to metric match" I referred to is 0BA which is almost exactly a M6-1.00 thread, others aren't as good. The company (UK location) sells both BA fasteners and taps/dies.
Another source for BA fasteners, taps and dies is https://britishfasteners.com/ located in New York State.

[rob love]

Originally Posted by Bruce Parker

BSF tap and dies sets are available quite easily. BSF is the same as 'NF' except the pitch of the threads is 55 degrees instead of 60.

Not sure what you mean by "is the same". None of the threads per inch (TPI) match between BSF and UNF.


I will agree that any of the BSF, BSW, or BA threads are easily available on ebay as well as other sites. Even left hand threads can be found with a bit of effort.

[Ron Pier]

I have a complete range of BA taps and dies from 0BA to 6BA. It's easy and cheap here in UK. I use this guy all the time for screws/nuts/bolts etc. taps and dies. https://www.ba-bolts.co.uk/

Ron