Category Archives: Radio

DPM Radio Carrier Backpack

Alongside the standard PLCE webbing sets were a number of specialist rucksacks and carriers for particular pieces of equipment. Radios were one of those items that needed specialist carriers and tonight we have an example of the rucksack issued for use with the 320, 350, 351, 352 and Cougar radio systems:imageThis large pack is made of DPM infra-red resistant Cordua nylon and is fitted with a pair of padded shoulder straps, a padded backrest and a waist belt to help support the weight of the radio:imageZips are provided to allow two 10 litre PLCE bergan side pouches to be attached to the pack to increase capacity, and a further small pocket for a spare battery on the bottom of the front piece. This is secured with a black plastic nexus fastener and Velcro to secure the pocket flap:imageThe main compartment of the pack opens with a long single zip that allows the whole pack to open up into two parts. The main, padded, part has a selection of securing straps to allow the different radios to be secured inside:imageWith the 320 set, the radio sits above, with the battery stowed beneath:dpmframeThe lid portion has a small pocket to allow a folding aerial to be stored here:imageA single label is sewn inside with NSN number and details, sadly badly faded in this example:imageOf all the radios carried in this rucksack, the 320 is probably the best known- part of the Clansman family of high frequency radios introduced in the mid-1970s that lasted in service until the 2000s. The 320 could be carried with a (not very) light metal frame carrier or in a rucksack such as this one which was presumably much more flexible and comfortable for use in the field. The metal GS pack frame weighed 3.5kg, this rucksack just 0.5kg so there was a clear advantage in the field to using the lighter fabric rucksack.

Military Marked Radio Valve

World War Two saw the meteoric rise of electronics in warfare. From radars to radios, electronics were the new wonder weapon and all sides invested time and money in perfecting the systems. This development was largely due to the vacuum tube, or radio valve in British parlance. This was a device, invented in 1904, that passed electrical current from one electrode to another in a vacuum and allowed far more sophisticated electronics to be developed. It was not until the 1920s and 1930s that the cost of manufacturing valves dropped enough that the technology became widely exploited and the British military were rapid adopters of the new technology. Like everything else, British military radio valves were clearly marked as such.

I have not yet been able to identify where this valve is from, but it is typical of many in use during World War Two:imageThe valve is made of glass, silvered and painted black, with a large plastic socket on its base to allow it to be plugged into whatever electronic device it was designed for:imageA /|\ mark indicates its British Army ownership and a stores code is also printed on the outside of ‘ZF8B’:imageA metal spike is attached to the top of the valve, although I am unsure what its purpose would have been:imageChris Foulkes was a developer of military valves in World War Two, this is his story:

At the outbreak of war an electronics company, STC Ltd had a factory in Woolwich. There they made valves, not just for domestic radios but also specialist types for radio transmitters and the newly invented radar. Chris Foulkes was a young design engineer in the development labs. Both Britain and Germany recognised the potential strategic advantage offered by radar and were in a race to develop better systems. The Woolwich factory became a priority-bombing target, mainly because it made valves, without which radio equipment could not work. The Germans probably did not know how far advanced we were with radar although they did have spies out, one of whom was suspected but not caught before absconding. The War Department arranged for the whole factory, all equipment and personnel to be relocated to rural Somerset.

In Lufwaffe raids the bombers had formidable protection from night fighters and there was an urgent need to find a way of giving our defending fighters a better chance against them. Britain was ahead in the radar race and the idea was conceived to miniaturise radar sets to be small and robust enough to be carried on our own night fighters. A downward-looking radar system called “H2S” was already in use in bombers, which gave some rough view of the ground through cloud cover. The need was for forward-looking radar with the detailed resolution to pick out a fighter aircraft and distinguish it from a bomber, with a display that the pilot could use for guidance towards his target and aim. The equipment hardware was made by EMI to use special valves developed by STC: small, tough, with suitable power and able to operate reliably at the necessary frequency. The design fell to Chris and the engineers in the Development Lab.

When the time came for testing, a prototype set was fitted into a Beaufighter and flight tested by John Cunningham. Already an established fighter ace, he had also been a part-time test pilot for DeHavilland before the war. After initial testing, when the DeHavilland Mosquito became available it was found to be a natural test-bed for all manner of purposes and Cunningham was the natural choice to fly it for further radar development.

His mounting successes against night fighters were announced in BBC news broadcasts and celebrated as a booster for public morale. It was important to avoid Germany guessing that Britain had developed viable airborne radar. A cover story was put about, that Cunningham’s success came because he ate a lot of carrots thus improving his night vision. The nickname “Cat’s-eye” was created for him, suggesting that he could see in the dark, like a cat. Testing continued until the system was well enough developed and was put into major production for supply to all fighters engaged in night flying.

At the same time as airborne radar was being developed, other systems were developed, to improve ground-to-air radar and to put radar on ships. When all the radar valve designing had been done, Chris designed valves for “submerged repeaters”, which were amplifiers inserted every few miles along the transatlantic telephone cable to America, to improve signal quality. These valves had to have very long lives, as dredging up the cable to repair a repeater in mid-atlantic was very complex and expensive. Many of these original valves were still operating in the late 1960s, when the repeaters were changed over to transistorised systems.

Larkspur A14 Radio Pack

The Larkspur Radio set was developed after the Second World War to take advantage of the improvements in radio technology that came out of the conflict. There were many different models of radios designed to be fitted to vehicles, used in bases and some man-portable models that could be carried on an operator’s back. These radios were very heavy so specialist packs with padding were designed that not only protected the radio from the elements, but also helped reduce the fatigue on the operator of carrying it. Tonight we are looking at the pack issued with the A14 man portable radio’s carrying pack:imageThis pack features many similarities with the 44 pattern jungle webbing in use at the period, including the colour of the webbing fabric and the style of the ironmongery attached to it. The complete pack with radio looked like this example:CaptureMy thanks go to Michael Whittaker of Grandad’s Kitbag for permission to use this photograph. The front of the pack has a series of loops and buckles. Two sets of straps and buckles are fitted to the top part of the pack:imageThese undo and allow both sides of the top portion to open giving access to the radio itself (obviously missing here):imageThe back of one of these side opening flaps has a leather and celluloid pocket sewn to it, presumably for a card containing important information needed by the radio operator.imageBeneath this part of the pack is another compartment:imageThis opens downwards and outwards to allow access:imageThis compartment was used to store the headsets, handsets and their associated cables needed to operate the radio. A separate aerial case was often slung over the rear to carry these components. To the rear of the pack are a pair of adjustable shoulder straps:imageThe weight of the radio was clearly quite considerable so a number of padded supports are sewn on to increase the operators comfort:imageThe only markings on the pack are a maker’s initials of ‘BLG’ and a date of 1964:imageThis pack is superbly well made and very complicated in design. This is the second Larkspur component I have picked up and I can see this being another radio set I will end up collecting as we go forward. I am a big fan of British military radios, unfortunately they are large and expensive so as with so many areas of my collection, this is a back burner project!

Clansman 349 Radio Holster

My thanks go to Michael Fletcher for very kindly giving me tonight’s object, a carrying holster for a Clansman 349 personal radio:imageThe 349 was a component of the Clansman radio system used by the British Army from the 1970s until 2010. This particular radio was for intra section communication and was a small personal radio worn in this holster on either the chest or back:CaptureThe holster is made of a dark green butyl-nylon fabric, very similar to that used on the 72 pattern webbing set. The main section of the holster is a simple square pouch that the radio slips into:imageThere would have originally been an elasticated cord and tab which fitted over the radio and attached to the Velcro at the top but this has been removed. The rear of the holster has a cut out to allow the user to reach the controls of the radio and a couple of pieces of padding to help cushion the wearer’s body from the corners of the radio:imageSadly this particular cover has suffered a bit over the years and the buckle for securing the chest strap has been removed, where this strap joined the rest of the cross straps a reinforced triangle of material is sewn, but the fastening strap which would have been to the right is cut off:imageThis originally had a tongue to go through the metal staple here:imageThe height of the pouch on the body is determined by a metal slide buckle:imageThe markings on this pouch have almost completely worn off, the fabric not holding the ink very well. You can however just make out the faint traces of an NSN number:imageWith Clansman being in service for so long there are a number of pouches available for the 349 radio and I have seen some DPM examples available online. With this being the case, I would guess that this is an earlier design of holster, but it seems to have remained in service alongside the radio throughout its service history.

Bowman Man-Pack Data Terminal Carrying Case

The modern battlefield is now full of electronic devices, with specialist radios, computers and tablet computers in use. These differ considerably from their civilian counterparts, being far more rugged than the relatively delicate mobile phones and IPads we are used to. The British Army use a system called ‘Bowman’ which in addition to having individual and unit radio systems, also has battlefield tablet computers called ‘LTDTs’ and a light weight man-pack data terminal produced by a company called L-3 Communications, called an ‘LMDT’:imageThe Army’s website describes Bowman as:

BOWMAN exploits the latest developments in radio and computer technology to meet the needs for services well into the 21st century.

Designed to provide an integrated digital communications network interfacing with higher level systems and networks such as ISDN, Skynet V,Cormorant and FALCON.

Commanders at all levels are given secure voice and data communications as well as an integrated Global Positioning System (GPS).

Tonight we are looking at the carrying case for one of the LMDTs:imageThis is made of DPM camouflaged Cordua nylon, and is fitted with a large belt loop on the rear to allow it to be attached to a webbing set:imageA small handle is fitted to the top of the case:imageA heavy duty shoulder strap is fitted, securing at two points on each side of the case:imageA heavily padded section is attached to make the LMDT more comfortable to carry (presumably it is a fairly heavy bit of kit!):imageThe front of the case opens up, it is secured with two black plastic Fastex fasteners:imageUnderneath this are a further pair of velcroed flaps that add protection to the screen of the LMDT when it is stowed away:imageFinally when the case is fully opened up it looks like this:imageTwo elasticated straps help hold the LMDT secure, even when the case is open. NSN details are printed on the underside of the top flap:imageThis is a beautifully well made case, and clearly very carefully designed, with openings and flap[s all over to protect the instrument, whilst still allowing it to be easily used. At this stage it seems unlikely I will find an LMDT to fit inside the case any time soon, but these things have a habit of appearing on the surplus market in due course as equipment is upgraded so perhaps something for the future…

DPM PRR Radio Pouch

One of the most radical changes to military operations in the last ten to fifteen years has been in the area of personal communications on the battlefield. Today soldiers each have a ‘PRR’ or Personal Role Radio, which allows them secure and quick communication between members of a section on the battlefield. Up until very recently troops had been forced to use whistles or hand signals. The PRR consists of a small headset and microphone that the user wears beneath their helmet and a small receiver and transmitter unit that is normally worn high on the chest, by one shoulder. This transmitter/receiver is carried in a small pouch that holds it securely in place whilst still allowing the operator to access the controls:imageThis pouch is made of a lightweight, but very strong Cordua nylon. Down the side of the pouch are a pair of openings that allow manipulation of the radio’s controls:imageAn elasticated strap is fitted to the top, with a press stud, to secure the PRR into the pouch so it does not risk bouncing out when the soldier runs:imageA pair of adjustable straps with Fastex fasteners are fitted to one side of the pouch:imageIn service these are passed around the back of the pouch, around the shoulder strap of the soldier’s webbing and back to the front to fasten and secure the radio pouch:prr-radio-pouch-british-dpm-bowman_1_1be3896179d1e205df1c22ada38d6a25The label on this pouch is very small and has no more information than an NSN number and the pouch’s use:imageThese radios are part of the troubled ‘Bowman’ system and the MOD ordered 45,000 of them in the late 1990s/ early 2000s. The British Army website gives the official position:

The Personal Role Radio (PRR) is a small transmitter-receiver that allows infantry soldiers to communicate over short distances.

Effective even through thick cover or the walls of buildings, PRR enables section commanders to react quickly and efficiently to rapidly changing situations, including contact with the enemy, greatly increasing the effectiveness of infantry fire teams.

PRR is issued to every member of an eight-strong infantry section.

The system is easy to use through its simple man-machine interface, is unobtrusive and comfortable to wear yet is rugged enough to sustain the harshest environments.

The use of PRR has significantly enhanced combat effectiveness by providing all informed communications to front line soldiers, replacing traditional methods based on shouting and hand signals.original-dpm-pouch-headband-set_360_8b4cc8609a8b25976ff43944c663f359

No 19 Set Morse Key

There were many variations of the humble Morse code key in use by the British during the Second World War; some sources identify up to a hundred different variations. Tonight though we are looking at just one of these, a little Bakelite example:imageThese little keys were used by signallers to tap out messages in Morse code and were normally wired up to a wireless set, which then sent out the dots and dashes as a wireless signal. Alternatively the key could be wired to a signal lamp, more on that in a few days! Examples could be made of brass, Bakelite, silver alloy or sometimes a combination of materials. This example is made of very robust brown Bakelite. It consists of a base and a spring loaded rocker arm with a large Bakelite knob at one end:imageThe base of the key has a stores code marked on it:imageIn this case it is marked ZA16929, and according to the Imperial War Museum’s online database this indicates the key was used with the Wireless Set Number 19. A second marking at the end of the key reads ‘Key WT 8 Amp No2 MK III’:imageThe key works by completing or breaking a circuit every time the knob is pressed down. Normally the connectors nearest the knob are broken and the ones furthest away are connected, pressing down on the knob reverses that position:imageThis gives a great deal of flexibility allowing the key to be used regardless of how a wireless transmitter is wired- just attach the wires from the transmitter to the relevant connectors on the key.

Rod Balkham describes how he learnt Morse:

Over a period of what must have been several months I was turned into an OWL B3 – that is, Operator Wireless and Line (B3 being rated higher than B2, I seem to recall). This transmogrification was achieved mainly by the challenge of competition, plus – in my case in particular – my instinctive reaction to the sensitive understanding of the corporal who was our teacher. Unlike many another army corporal, he commanded respect in a firm but kindly manner, and he knew his job. As with the Bren gun, I became proficient with the Morse key without having to try very hard. To help us learn the Morse Code, the corporal offered us a few mnemonics, based on the rhythm of the dots and dashes. One was ‘Here comes the Bride’ – you can think of the bride as the Queen, he told us – thus arriving at dah dah dit dah for the letter ‘Q’. Another one, which I have good cause never to forget, was ‘Did-it ‘urt cher?’: Dit dit dah dit for the letter ‘F’, followed, inevitably, by ‘Like ‘ell it did’ for ‘L’.