I love a nice piece of British communications gear, and tonight we are looking at a really interesting new addition to my collection. The ‘Telephone Loud Speaker Control Unit’ was issued to artillery batteries during the Second World War and allowed the battery commander to communicate with the four guns in the unit and provide immediate instruction on things such as range, shell type required and corrections. Altogether the set comprised the control unit (which we are looking at tonight), batteries and four speaker/transmitter units that went out to each of the guns. The control box was in effect a miniature switchboard for a five way field telephone. As with most British Army communications kit of World War Two, the control unit is housed in a stout wooden box, with the contents painted on the lid:The box weighs 22lbs when complete, so is a heavy piece of kit. There would have been a carrying strap which is now missing (although will not be difficult to replace). Opening the box up we can see it splits into two parts, with the main switchboard in the bottom of the box and storage for headphones and microphone in the lid:Four terminals are provided to connect each of the speaker/transmitter units to. A switch beneath allows each or multiple gun sites to be chosen to speak with, a bulb lighting up to show which ones are connected:A pair of terminals are provided on the main control panel, the larger being for the microphone (which I am sadly missing):The smaller terminal allows the headphones to be plugged in:The back part of the bottom half of the box has two coiled wires with terminals:These are to attach the system to a battery box, and standard Niphan plugs are attached to the ends of the cables:The lid of the control unit holds the accessories for the set, with a tinplate cover revealing a space for the microphone:The top of the cover has details on how to operate the set, note also that this set was manufactured by Truvox, other examples were produced by Tannoy:As with the microphone, a white outline indicates where the headphones are to be stowed:These are secured in place by a webbing strap with a turn buckle:A small tinplate cover reveals a space for spare bulbs for the control box:The headphones provided are very similar to those used on other British Army radio and communications sets, with a pair of Bakelite speaker units and a wire and web harness to attach them over the operator’s head:In this great photograph we can see Lieutenant LW Spurr directing the fire of the 25 pounder guns of the 4th Field Regiment, Royal Canadian Artillery near Antwerp with one of these control units:A typical order from a Gun Position Officer to the crews of the guns might be, “HE, 117, Charge 3, zero 346 degrees, angle of sight 2 degrees, right ranging 7700, fire”. This meant the guns were to fire an HE Shell, with a 117 direct action fuze, using a charge 3, at an angle of elevation of 346 degrees deviation from the guns zero line, at an angle of elevation of two degrees, only the two guns furthest to the right of the controller are to fire and the range is 7700 yards.