Wireless of the Week - week 19
 

At some point all the various field phones and remote control units have to be linked together into a network and, drawing on the civilian example, switchboards were developed for military use. The British Commonwealth version of this for field use was the Switchboards, U.C. 10-Line and Switchboards, U.C. 6-Line. These switchboards (U.C. standing for ‘Universal Call’) were designed for local office use or at Divisional Signals for the 10 line, and at Battalion and in Artillery Regiments for the 6 line. These switchboards were used throughout the war and as late as the 1980’s in cadet corps.

The units are housed in aluminum cases 8” by 8” by 17” (UC6) and by 21-1/2” (UC10) that have a hinged panel on the front that protects the switchboard controls and acts as a tray that organizes the plugs and pulleys. Another panel on the rear allows access to the wire post connections as well as the internal parts and battery box. On the side is a hinged box that stores the plugs, headset and night alarm when not in use. These boxes may be mounted on either side or removed completely so individual switchboards may be used together. The switchboard itself is made up of modular, replaceable sections that have a B jack on the bottom, an A jack at the top, a numbered lamp to indicate an incoming call (and for testing the unit) as well as a white plastic panel where the operator can write down who is at the other end of that particular wire.

The operator uses a handset or alternatively a breast plate with an attached microphone. A night alarm bell is available to let him monitor the board from some distance away…like his cot. The system has a noise limiter to help with incoming line crackle and switching spikes.

These UC switchboards are very robust and with a few modern D cell batteries in place of the war-era X cells they usually work with no extra tinkering. The remaining question for signals collectors in Canada is why you can still find UC10’s yet UC6’s are almost non-existent.

Superposing the UC 10
 

firstly, many thanks for your efforts in photographing and posting with concise info on all this fascinating Kit Bruce.

My UC 10 needs a polish.
I've not powered it up in the 20 years I've had it but your posting inspires me to do so.

Best score I had was a set of NOS drop leads from a deceased estate.
I sent my original, slightly frayed, set to Canada in a swap for some LARX kit.

My contribution to your photographs is a Superposing Unit.
When I purchased it I didn't know its significance in relation to the UC 10 I already had!

in action
 

its always great to see 'our' kit in its intended role.

Ah... so that's what the Superposing unit is for!

Have some somewhere which are surplus to my needs.

Tim

Surplus to you needs eh? Maybe my people should contact your people about that...??

There are two different Superposing Units, but you don't actually need them for the exchange. Their purpose is to "piggyback" additional circuits onto existing lines (e.g. Fullerphone or Teleprinter which are DC telegraphy onto a telephone circuit (all AC) without mutual interference) or to create "Phantom" circuits when there are not enough lines for the expected traffic.

Superposing Unit 1 Transformer is the illustrated cube, and lets you create an earth return phantom circuit or piggyback a Fullerphone onto a speech pair. With more of these (and more pairs available) you can create phantom and "super phantom" circuits. I think it's all in the manual (which is not to hand right now due to the impending house move).

Superposing Unit 3 Transformer is a rectangular box that fits on top of the 10 line U.C. switchboard. It has a fan-out of wires to connect it to the switchboard, and two 10-way sockets to connect the whole assembly to "Box, Terminal, Signal Office", possibly by way of "Frames, D&P, 10 wire" if required. (D&P is Distribution & Protection, and it contains fuses and lightning protectors for each line, plus jumpers to allow rerouting in the event of faults, and hooks to allow more Superposing Units (1 Transformer) to be added to the setup.).

Chris.
(I'm still looking for the 3-transformer superposing unit, the Box, Terminal, Signal Office, and the connecting cables to link it all together; just not right now!)

Someone has... would this be one of "your people"... or someone else?

Tim