Listener's Guide

Classic Military Receivers

We look back on some of the great army surplus sets that made the amateur radio hobby

Thinking Back To Our First HRO

Seeing these great receivers again on Channel Four's series on Station X reminds me to be a Radio Man in the Sixties meant getting an HRO.

Ours had UX Series valves leading up to a Type 42 in the output stage, its anode brought out to a screw teminal. A second terminal carried the HT.

Ignoring the manual, these were connected to the loudspeaker. Seemed very faint for such a highly regarded radio?

After the electric shock had thrown you across the room a few times, we learned an output transformer was needed to match output valve to speaker. We know that now...

You changed bands by changing the entire coilpack. Switch off B+ (the HT) before changing coils or the shock threw you across the room again. There were nine coilpacks in a wooden rack - very collectible now.

Opening the lid of an HRO took you into a world of wonder. The tuning knob ran a scale up to 500 but you never saw the numbers change. The transverse-mounted tuning gang with the signal circuits regimented in a straight line. The sinister glow of the S Meter, the scale discoloured by the passing years.

It was so quiet. It seemed the signal-to-noise ratio consisted only of signal. Working with the graph on the front of each coil-pack, you spun the dial to be, give or take parallax error, indifference to chart-reading, rounding up or down the scale setting, plus or minus 100Kc/s of where you wanted to be. Then you just listen around.

Bandspread coils were wonderful. Top Band covered in about thirty turns of that magnificent tuning drive. It took about six to get through Loran. Tuning AM was a challenge. The slow tuning rate and the broad flat-topped IF response resulted in the ballistically-challenged S Meter hardly showing a peak. Happy times!

These days they tell me a modern home hasn't the space to accommodate a military set. As I write this on a PC, this thought strikes me. It takes up about the same room as a HRO.

Wireless Set Number 18

Wireless Set No. 18 was the first mass-production man-pack radio station for the British soldier. Made by Pye, the set consists of separate tuneable transmitter (TX) and receiver (RX) units mounted in a back-pack.

If you are on CCF Ops, the trick was show the poor sap about to pick the 18 Set up just how light it is, then fit the integral battery in in the base of the case. Collapse of stout party.

If got your set at a rally, you had to make your own power supply. You either got the filament or HT voltages wrong but in any event you killed a good few valves.

The valves used were fragile 2 Volt filament types. The internal valve filament support springs fractured during rough handling of the set, a way of getting out of Wireless RT Training. Another way was to remove the valves and throw them against a wall at dusk. In the failing light, the satisfying pop was met with a blue flash.

The set used a sectional vertical rod aerial to inflict minor RF shocks to junior ranks. Alternatively a long wire ground aerial could be used to make the set heard over greater distances. In CCF Service, that was the last thing you wanted.

Production was from 1939 to 1945, range 6 - 9 MHz and transmitter RF output about 0.25W, not really enough for a decent RF burn.

PCR Receivers - Entertaining The Troops

Portable Communications Receivers Type PCR, PCR2, PCR3 were a series of general purpose lightweight sets used by the British Army from 1944 until the late 1960s.

It was a 6 valve superhet, a variation of the RX section of the Wireless Sets No. 19 but with better RF selectivity, narrower IF selectivity and a higher power audio output stage.

Valves such as the 6V6 or EL32 had the same pin connections as much more powerful valves like the EL34 and KT88. A simple swap could fry the output tranformer before the power supply burned out but in the few minutes before the nasty smell, a PCR sounded great.

The frequencies covered were 2100 - 850 Metres LW, 570 - 190 Metres MW and 5.8 - 18MHz SW with the luxury of an internal loudspeaker, making the radio almost self-contained.

Bought as military surplus, you had the option of an external power supply. Save a few bob by building your own, there was plenty of space on the chassis and you could get rid of the non-standard inter-connect leads.

With a beefy PSU and an upgraded audio output valve - a KT66 was the mod of choice - Radio Caroline really rocked. Mine was made by Philips Lamps and was one of the 17,000 units produced.

The PCR is often described as a NAAFI receiver for entertainment only as, lacking a BFO, single-sideband reception is not possible. We used ours as a domestic military-styled AM radio but it was seen as much more in Service life being supplied by the RAF to Resistance Groups in Norway, Holland and France.

Wireless Set Number 19

Bought from John's Radio in Bradford for around twenty quid, mine was that bit more expensive as I had the PSU too.

No manual. In the dying hours of my birthday, decided to go through all the pins on the O/P socket looking for audio with a multi-meter. Found it and Luxembourg on 6.09 Mc/s. Luxy opted out of it German Service at 1915 for a dose of religion then into The Great 208 at half-past.

Odd to think that Fred was on GB2RS duty with DADARS News even then. Tom Darn was one of the contributors, some are still at it today. Tried a goniometer but, then as now, don't know what it was supposed to do. Something to do with phase?

For serious gain, link in the I/C Amplifier. This was for mic/headset comms in the tank but here, with it's transformer input/output 6V6, gave the set a real output stage. Some has a B SET for VHF, but in all cases the TX was disabled. You had to find 500v for the 807's plate for about 40W of suppressor-grid modulated AM off a carbon mike. And we won the war with these?

The Canadian Wireless Set Number 52

The Canadian WS52 Receiver was designed and built in Canada by Canadian Marconi to be used mobile or a ground station.

The mechanical design is excellent and contributes to its stability. It is possible to tune in an SSB station with no need for readjustment over long periods, unlike many of its contemporaries. Not bad for a set never intended for sideband working.

The frequency range is from 1.75 to 16MHz and it has a crystal calibrator which enables any frequency to be set up within 5KHz, fine for AM working.

The tuning dial is similar to that used in the 19 and 22 sets with a mechanical FLICK/SET/TUNE facility, as near as they got to a memory system. The three bands are colour coded:

Wireless Set 52 Bands
Band 1Green
Band 2Yellow
Band 3Orange

As an eight-year-old operator of this receiver, the same colours on the band change switch made tuning a doddle, especially as we had dumped the manual as so many of its professional users had years before.

Above the main tuning dial is a fine-tuning adjustment, spring-loaded to centre. A meter reads for both the Receiver and Transmitter and enables every valve in the set to be checked. Monitoring a valve under AGC control offers tuning indication, going for a minimum reading.

For CW use, the set really comes into its own. Unlike most others of its class, there is a good CW filter tuned to around 800Hz, it not only cuts out unwanted signals, but boosts the wanted one.

The circuit is fairly conventional for the period with one RF and two IF stages, the first two IF transformers are double tuned and the coupling is increased by putting the selectivity switch to FLAT.

There are 13 valves used in it - all 12 volt and mainly ARP3s.

The IF frequency is a non-standard 420KHz.

The main fault to which they seem to be prone is the common one of resistors going high or open circuit. It is worth checking them all, as the set is easy to work on. The same goes for the capacitors.

The sensitivity of the receiver is almost up to present day standards, being in the region of 0.7 microvolts for a 10 to 1 signal-to-noise ratio in CW and 2.5 in AM.

It is also protected by a gas discharge tube across the aerial input, something that scared this eight-year-old operator. His bother told him it was a bomb, set to detonate if I did not let him have his turn.

The Classic Military Radio Blues

I worked for, and with, John Wilson for about twelve years up at the Matlock Emporium. They say you only get eight for Aggravated Burglary but I digress. In that time John demonstrated a life-times radio engineering experience allied to a powerful sense of the aesthetic. I, on the other hand, have a somewhat shorter life-times experience married to a sense of the faintly ridiculous.

What John has missed entirely is the value of the oversized Military wireless as a replacement for furniture and as a fashion statement. The first radio to have pretensions toward being a bedside table was a SETS RECEIVING: CANADIAN NO 52, a rather large Christmas present given as a bribe for peace back in 1963. Our house already had things the grown-ups called occasional tables. OK then, the 52 was occasionally a table and mostly a radio. It was smuggled into the house under cover of darkness after delivery from Everybody's Store in Coxbench - a Derbyshire village name first to fall foul of my schoolboy humour. They were glad to see the back of it, no doubt.

It came with an enormous power supply, the on/off switch - based on a design stolen from the set of an early Hammer horror film - placed jauntily above the power output socket. This was a Bakelite casting, an International Octal surface mount with the pins standing proud above the front panel. If you switched on without the plug in, your finger would come down on the HT pin, initiating an early form of aerobics. Health and Safety legislation has taken so much from the hobby.

The 52 SET got me cricket from the antipodes, merry greeting from Tirana and the start of a lifetimes listening to World Service. Then the Empire and General Overseas Service of The BBC, now World Service Radio and almost unlistenable.

Remembering those early days, we recently set off on a pilgrimage to Coxbench - only to find that Everybody's Store is now a part of the elevated section of the A38. The pub is still there, though. We were able to test that.

Among the things the 52 SET lacked, apart from sensitivity, selectivity, frequency accuracy or stability, were the broadcast bands. If you were an AM DX'er in those days it meant the only receiver to have was an R1155. John likes those. Mine had a vibrator power supply, a curious electro-mechanical method of producing the high voltage needed for the valves from a car battery - and not what you are thinking. Receiving at maximum gain drew thirteen amps or more, requiring an overnight battery charging session if we were to catch the jazz next day from Allouis. We must have listened in a constant heady atmosphere of hydrogen and oxygen from the fizzing cells which probably explains this writing style.

You see, the R1155 had no audio stages. You either listened on an ex-Army headset (the original design based on a wireless operator who had ears in a different place to the rest of us) or you ripped out the DF or Radio Direction Finding part of the set and fitted a little amplifier. This was a 6J5G, a 6Q5G if you wanted bags of gain and microphony, into a Class A 6V6G. These are classic valve types that will mean nothing to a generation brought up on MOSFET current-dumpers and long-tailed pairs. I belong to a generation that regarded the sub-miniature 6V6GT as a form of hi-tech. Anyway, this power duo got you two-and-a-half watts of pure distortion.

The height of technical snobbery at that time was to strap the anodes together with a 1.5M resistor so each one of us who did this could lay claim to be the inventor of negative feedback. Being a good old fashioned self-publicist, I invented my own form of negative feedback. This was to connect the secondary of the output transformer in series with the output valve's cathode by-pass capacitor. Yes, I know Quad was doing it at the output of their Series 2 amplifiers, but the self-taught will never acknowledge plagiarism.

I digress, again. Then there was the R107. This was a seaman's chest of a radio, doubling as a larger bedside table than the 52 Set. Power was presented to an R107 via a Mil-spec connector that was nearly the size of the old two-pin kettle plug. The writer, as a young man, thought they had simply got hold of a duff kettle socket so applied the plug with a toffee hammer. This was the node for all the electrics, the table lamp atop the R107 and a fan heater. You could get all the wires in if you removed the cable clamp from the kettle plug - and all this with no earth, Health and Safety take note. How we made it to adulthood, I'll never know.

At least the R107 had plenty of room inside for modifications. In those days, a man was judged by the size of his output stage. Build bigger, better - get the maximum wattage into your cottage. By the time the R107 got its new output stage, we were dicing with death. It had ultra-linear push-pull KT66's with four hundred volts on the plate. When Radio Caroline came on-air, the whole street knew about it.

The case was painted a satanic black. Two breeze blocks got the same treatment and went underneath as legs - a bedside table weighing in at about two hundredweight. The nights were lost listening to King Crimson on Big L's Perfumed Garden with one John Peel. No one could have heard the doorbell. The man wanted to buy The Radio From Hell, cost no object. For a fiver, the R107 made its final journey. It had fought and won a war for us - on the beaches, in the air and in my bedroom. Never before had so much been done for so little.

A month later it was spotted in a recce by my troops. Seen in a garden near Brailsford, the black case sans radio, the lovingly restored front panel replaced by chicken wire and two rabbits. And at the going down of the sun and in the morning, I still remember it.

Then there was the AR88D. Mine came in an oak case with the offer of a free hernia. Even then, there was a curious kind of inverted snobbery. If you were a proper short wave listener who listened to Hams and anything that was not Radio Moscow, you had the AR88D. If you enjoyed long-wave listening you were but a pretender to the hobby and had the AR88LF. These were seen by the hard-core as not a real communications receiver and people would turn their backs at radio rallies. I always wanted one. My AR88D is remembered for its excellent audio on which Radio Northsea International accompanied exam revision.

Remember Kenny Everett, who never quite got up in time for his Kenny and Cash breakfast show at Capital Radio, then on 539m - that's metres, by the way - on the Medium Rave Band.

To have that audio quality available for the music stations on long-wave would have been utopian. The Moscow Home Service then on 173 - that's kilohertz, by the way - played doom-laden pieces of the Russian classics that matched my teenage angst to a tee. (Short pause while broadcast antenna designers fall about at that last pun. I could be waiting a long time)

Anyway, Monday evenings ritual walk from The Rose and Crown pub - no drink problem, we used to live there, honest - lead to G3PTT's farm and a chance to drive the coveted AR88LF. There was (and still is) not a power on earth that would make him part with it.

Space does not allow for all the radio stories. If I am to suffer arthritis in the hands in later life, it will be down to tuning an HRO with a Top Band bandspread coil-pack. The real HRO men would scour the rallies for the wooden case that held the coil-packs and spend a dog's age restoring it with teak oil as the rest of the furniture in the house fell apart. The rites of passage when you get your first Racal RA17 with the rites of massage as the chiropractor tries to fix your back. The defensive remarks when you tell them down at the club that your other radio is an Eddystone 840C. The career-long friend who took you to the Derby Rally where you picked up a 62 SET, the same friend who hit the talk-bar as you rigged the aerial to see if you had a future as a dummy load. The games master who made you Net Controller for Derby School CCF Operations; Map Exercises, who could not understand why Geneva was concerned that Radio Silence was filled with Pink Floyd albums on three NATO frequencies. Had enough?

We won't see radio like that again. All I wish is that the new generation of listeners get the same sense of pioneering fun we did. Perhaps in forty years time, SWM will carry a nostalgic piece about the day the wife used an AOR AR7030 as a door stop. Oh, how we all laughed.