Wireless of the Week - week 10
 

Nothing is more typical of a British WW2 Tommy than his helmet worn on a cocky angle and a Wireless Set No.38 in its harness on his chest. It is arguably the most widely used and recognizable British/Commonwealth infantry set.

The 38 set is a lightweight portable radio designed for infantry work at the platoon or patrol level. Close to 200,000 sets were built by Mitcham Works (MW), Murphy Radio (MR) and Radio Gramophone Development (RGD) beginning in 1942 and were used in every theater by almost every Commonwealth country during WW2.

The 38 set featured is a Mk.2* version. Other versions include a Mk.1 which has the set and battery in one case, a Mk.III that is a sealed, tropicalized set and an AFV version modified for use in tanks.

The set itself is housed in a metal box 9” tall, 6-1/2” wide and 4” deep weighing 7 lbs. This was carried in a skeleton web harness with a web waist belt and a ring to attach to a brace attachment on the operator’s left web shoulder brace. The complete station with battery, headsets, spare valves, haversack, aerial bag and signals satchel weighed 22 lbs. The controls on the face of the set were simple to use and comprise of an off/receive/switch, a frequency dial with a lock and an aerial socket that had a rotating cover acting as a dust cover for whichever socket was not in use. A plug on a cable went from the set to a junction box carried in the haversack on the operator’s back. The headset and mic plugged into this box which itself had a short plug and socket that connected to the dry battery in the haversack. Aerials were 4’, 8’ or 12’ rod ‘F’ sections (as used on 19 sets) or a wire ground aerial. A dry battery carried in the haversack on the operator’s back provided 3 and 150 volts to the set. Alternatively, the set could be powered by a hand crank ‘Supply Unit No.5’. Included with the set was a card with operating instructions so, in theory, anyone could operate it if the real operator became incapacitated.

Frequency range was 7.3 to 9 megahertz. Operating range was approximately a half mile with a 4’ aerial and 2 miles with a 12’ one. The true frequency in ‘megacycles’ was shown in graduations on the dial which also tuned both the sender and receiver at the same time. The only other switch the operator had was a three position switch that was either off, receive or send. Sending required he use this switch as there was no pressel switch on the mic. The mic itself was novel in that it had two leather pads with the mic pickups inside them worn on the operator’s throat. His voice was therefore picked up…quietly…from his throat rather than his lips.

One of the most frustrating things with a 38 set is replacing a failed valve. The front cover comes off easily enough by removing the four screws in the corners. The valve replacement is typical and of no concern. It’s getting the screws back on where the trouble starts and can only be accomplished with a good magnetic screwdriver or a lot of skill and patience. Once complete you are asked to shellac the screws for waterproofing which, after several valve changes, makes a mess of the radio.

There are actually three (slightly) different variants of the WS38 Mk.II.

The original had a small box on the top with a "Test" button and lamp to show that the set was indeed transmitting. This worked via a pickup coil around the feed to the aerial base so the lamp would only light with the button pressed, an aerial fitted to the base, and the set on transmit and radiating a signal. It was deleted on economy grounds fairly swiftly.

The second version had a plate screwed over the front panel where the test box would have been fitted. (Presumably while they used up the old stock of panels.)

The final version (as in your example) had a smooth front panel with no extraneous holes plated over.

I think the latter pair were marked as Wireless Set No. 38 Mk. II*.

Other minor modifications involved tying (or taping) the set cable along the top rail of the set, to reduce cable failures due to flexing where it passed through the front panel.

According to the manuals, it is supposed to be possible to run the set from the 162V/3V battery used by the WS18 & 46, but that either requires an adapter that I've never seen (5 pin plug to 4 pin socket), or a modified junction box with the 5 pin plug fitted.

There was also a battery using "can type" cells for the HT section instead of the layer type, but these had a high failure rate in the tropics and required regular testing while in stores.

Chris.

Hello Chris
"According to the manuals, it is supposed to be possible to run the set from the 162V/3V battery used by the WS18 & 46, but that either requires an adapter that I've never seen (5 pin plug to 4 pin socket), or a modified junction box with the 5 pin plug fitted."

Like this?

http://i105.photobucket.com/albums/m...pin%20plug.jpg

Geoff

Hi Geoff,

I've got one of those, and think it's from the Supply Unit No.5 (the hand generator, 3 lead-acid cells, and vibrator pack all in a WS18-sized case) intended for the WS18 or WS38 (the latter may have been an afterthought since the supply unit is several times the size and weight of the WS38). Also that cable is far too long to be a battery adapter (if such a thing actually existed in the first place). It's UX5 (807 valve base) to B4 socket, and the WS18 battery socket is rather smaller than a UX5 base.

Most likely explanation is that if/when they ran out of the correct batteries for the set, they'd get a shipment of WS18 batteries and the radio mechanics would have to swap the battery plugs from 4 to 5 pin as necessary. (The obvious method would be to make up replacement junction boxes from stuff held in stores and issue those.)

Chris.
(I'm expecting to find all kinds of things that I thought were lost for ever while I'm busy moving house - there's an entire loft full of clutter for a start!)

poor chap
 

The poor guy with that 38 set has faded away to nothing, a case of massive neglect or lack of food .

Was there a 38AFV set ??? I seem to recall seeing some over here

Yes indeed! Intended for AFV communication with supporting infantry. The original approach was a standard WS38 and batteries connected to a Control Unit No.12 that "sort of" worked with the existing WS19 wiring harness.

Later there was the WS38AFV and its Supply Unit & LF amplifier which saw the WS19 Control Units 1 & 2 replaced by 17 (for 1) and 16 (for 2) giving full intercom and rebroadcast facilities.

Chris.

...post WW2 the WS38AFV was replaced by the WS88AFV and WS31AFV for infantry liaison, again they needed power supplies and LF amplifiers to match the set to the vehicle and control harness audio levels, and the WS31AFV supply was available in 12 and 24V versions (by replacing the power supply subchassis in the PSU/LF Amplifier unit).

The Canadians did something similar using the CPRC26, and I think the Australians used the A510 - someone on here had a control unit with "510" on the switch!

Chris.

WS38 in Canadian use
 

The Canadian Army Overseas showed interest in the WS38 in early 1943. A request of 9 April 1943 for 20 sets for training purposes was placed with the UK.
Besides the infantry the set was adopted for armoured regiments. It was accepted on British scales and could be requested on a 1098.

Initially only the battery version was available (Plan A) and was fitted to purpose. The later AFV version (Plan B) replaced these. The set remained in use through the end of the war.

Here are some reports on the set.

Thanks Bruce, great info. I plan on doing the 38 AFV soon. One question: on the middle document, paragraph (f) it talks about a future man pack working with the 29 B set. That set works on 235 MHz and 245 MHz and I know of no man pack set produced or in development that worked on those frequencies. Do you have any idea what they were talking about?

Bruce P.

Not sure, but when I read that comment regarding the 29-Set, I read it as being an interchangeable module was to be developed such that some tanks would have the standard B-Set removed and the Infantry capable 38-Set module slid into the empty B-Set case, ready to go.

David

I read it to mean that the 29 B set (not unlike a 19 'B set') would communicate with a 'future' infantry man pack operating on the same frequency. I'm fairly certain nothing ever came of of it.

I read that paragraph over & over and it was a bit of a mystery. It could be a new manpack itself or as suggested a replacement module for the C29. Must do some more research.

Here is my WS38. Mine has the neck strap for holding the set centred on the chest. The operator cards are ones I made using a scan from an original from David Gordon.

38 set
 

Here , 38 set

http://www.ebay.com.au/itm/WWII-Wire...cAAOSwKfVXIcI~