Loudspeaker Mystery

[Euan McDonald]

I have a pair of the same looking speaker that belong to a Tannoy set up. The speaker lock together as a pair for transit and the control box has connection for Four speaker and a mic. The Tannoy was used to communicate to field guns from gun controller.
I think someone like Mike Cecil would know more about this as I acquired mine from him.

tannoy.jpg tannoy-2-thm.jpg

[David Dunlop]

Bruce: Nice to learn the official name of these is Loud Speaker No. 2. On the back of the one I posted, I can see a trace of the original stencil, which seemed to have more information than just the later "LOUDSPEAKER" Stencil. I will have to treat this with some fine sand paper and see what turns up.

Is it possible these loudspeakers evolved through several versions? The set Euan posted seem to have just two terminal posts in the top corners of the front face. My four, and all the others I have ever seen in these parts have four terminal posts as per my original comments. Could these be a later version which provided more application options, or an earlier version for which the lower terminals proved unnecessary? That raises the question these speakers may not, in fact, require all four terminals to be connected in any given installation.

Euan: Thanks for posting your photos. The white outline around the signal button on three of your speakers is something I will have to look more closely for on mine. Yes, mine also lock together in pairs and each came with the 'standard' signals canvas strap that shows up on Fuller Phones, RCU's and the series of field telephones. Those suckers get right heavy fast when paired together don't they!

Hopefully some manuals will turn up dealing with these things one day.

Cheers for now.

David

[David Dunlop]

Sorry, I meant to ask this earler.

No rush, but when you get a chance, can you post some photos of the insides of that L.S. No.2 Canadian Control Unit Mk I?

Thanks,

David

[Johnny Canuck]

Hello David
Telephone Loudspeaker was used to control a battery of 25 pdr's or 4.2" mortars.
The L.S. No.2 Canadian Control Unit was located at the CP and connected to the Loudspeakers by 2 wire cable. The CP could send instructions to the guns and the guns could reply by pressing the Push button and then yelling into to speaker to send a reply.

Some scans from a 1943 British 4.2" Mortar Manual.

Geoff

[David Dunlop]

Geoff:

Thanks for the additional information. Every little bit helps in better understanding this equipment.

I had considered the speaker being used to 'mic' back information, as electronically there is little difference between mic and headphone element design/function, but the rather robust look of these speakers made me hesitate about that possibility.

I dug up a second speaker and it has been repainted so much all traces of original stencils are long gone and just the 'PRESS TO SIGNAL" new printing is visible. I have a second pair tucked away somewhere and must track them down to see what they can tell me.

Is the Control Unit a rare bird? With the large numbers of speakers that used to be lying about in these parts, I am puzzled I have never spotted the Control Units or manuals.

David

[Bruce Parker (RIP)]

Originally Posted by David Dunlop

Sorry, I meant to ask this earler.

No rush, but when you get a chance, can you post some photos of the insides of that L.S. No.2 Canadian Control Unit Mk I?

Thanks,

David

As requested:

[Jordan Baker]

Ive seen other pictures but this is what I could find.

[rob love]

I either have or had the CFTO for this setup. I may have given it to Derk Derin.

[David Dunlop]

This item showed up on eBay this past week from Holland. Appears to be a British Tannoy with a couple of noticeable differences from the Canadian Unit we have been discussing. I was tempted to bid but the shipping price could easily have exceeded the final cost of the unit. Also the differences made me hesitate.

The Canadian set has only four lines output, which makes sense to me as an artillery item. This British one, however, has six output lines, which is a puzzle. What would the two extra lines be used for, and would this have made the British set more versatile/flexible?

David