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Memories of a Patrol Sig
By John Trist - June 2014

I was a Patrol Sig in the early 70's during my service with the Special Air Service (SAS) Regiment. It was a rewarding job and often quite demanding as our primary means of communication was a CW radio set (AN/PRC 64) that only had a 5 watt output on CW. It was imperative to put a decent antenna up to ensure you got a good signal. The set was also known as the Delco 5300.

Apart from the SAS, the AN/PRC64 was also used by other Special Forces. The Regimental Sig course was fairly intense as there was a lot to cover over the 6½ weeks. We spent a lot of time in the classroom learning Morse code, Antenna theory, Antenna propagation and recognising the advantages of different types of antennas.

A lot of emphasis was placed on the importance of looking after the radio itself as the need for reliable communications in a 5 man patrol operating in a remote locality was of the utmost importance. I had been to New Guinea 1 on two occasions for three months in 1970 and 1971 and was fortunate to be in the same patrol as a very competent patrol Sig so I managed to pick up quite a few tips which proved to be useful later on.

We were required to be able to send and receive morse code at 12 wpm to qualify and to assist us achieve this we could take a radio set home of an evening and send back to Regimental Headquarters who maintained a listening watch for a Squadron or a Troop who were in the field.

  1. Well known author Ian L. Idriess wrote a book called Gold Dust and Ashes [1] in which he describes my cousin Les Trist who was flying gold in New Guinea in 1932 when his plane crashed into the jungle and he was eaten by cannibals.

The CW part (morse code) of the course occupied a large part of the curriculum and I recall driving home at the end of the day looking at the vehicle number plate in front and mentally converting it into Morse code. Every bird that called out was talking to me in Morse too! We were also tested on the other UHF and VHF radios that we could be expected to use in Patrol, Troop or Squadron exercises and operations.

The 64 set had a voice capability, although it was a very poor performer in that mode with a very modest 1.5 watts output. Although it was claimed to be waterproof to a depth of 3 feet it certainly was not, and great care needed to be taken at all times to keep it dry.

During training anyone who let their set get damp was given a severe reprimand by the instructors who emphasized that the radio was the lifeline of the patrol to the outside world so we took every effort to ensure the set was well waterproofed at all times.
AN/PRC-64 ready for use

The issue container it came in was constructed of a heavy Cordura type material with Velcro closures which were considered too noisy for patrols of a tactical nature so most operators discarded the container and wrapped it in a heavy duty waterproof material that included the antenna and the Morse key. Extra care needed to be taken when parachuting with this set to ensure it did not get damaged on landing. It was roughly the size of a loaf of bread and weighed 7.5 lbs so it was quite compact. In the 70's we carried smaller packs than they do today and we used to live like dogs in the field wrapping ourselves in a bit of plastic at night with a very lightweight sleeping bag or a piece of parachute material to keep warm.

The 64 set had an internal key on the top of the inner case and an external key attached to the set by a lead a little over a metre in length. The external key was quite good and most operators used the key upside down tapping the message out on their leg. The internal key was simply there as a backup.

In practice
Towards the end of the course we packed up and went on a long drive into the bush at an isolated location in West Australia to get some experience in putting up the various antennas, and having regular skeds with Regimental HQ back at Swanbourne putting into practice everything we had learned. I can well recall setting the radio up on the verandah of a pub in a small town for our sked before signing off for the day.

The antenna was cut to length prior to going out on patrol as we knew what frequencies we would be transmitting on from our Sig brief we received prior to insertion. We always carried a spare antenna in case you had to leave in a hurry and this was carried by another patrol member. In open country similar to the country around the Kimberley and outback Australia with a decent aerial you could get through up to about 1000 kms but you were never required to cover that distance on jungle operations.

We always carried a spare battery although it was often not required for a patrol of 5-7 days duration. The set had 4 frequencies and we were allocated a primary and secondary frequency and a lower frequency to be used at night in an emergency. We had a lost communications procedure so that if we missed one sked or more, certain procedures would be put in place to make contact with you.

Jungle operation
In the jungle the antenna was erected a little over head height, broadside to the station you were transmitting to and it was run out at the required angle by two people (one covering the other). The end of the antenna was tied off with a quick release slip knot so it could be pulled-in by the Sig himself without leaving the security of the patrol base. It was normal practice to use a dipole or an end fed antenna of about 15 metres in length.

I have a good friend in Perth, Bob Long, who is now 93 years of age. Bob was a Z Special Unit [2] operative 1 with Semut 1 in British North Borneo in 1945 and he wrote a book called:
Z Special Unit's secret war: Operation Semut 1 - Soldiering with the Head Hunters of Borneo [3].

Bob was a very good Sig and he used to tell me:

"Put up the best antenna you can, but sometimes you can get through on a piece of wet string!"
A soldier operating an AN/PRC-64 in the jungle [4]. Click to enlarge.

All our messages were encoded, and the Sig would sit down with the patrol Commander and make up the message and then it would take some time to encode it. If it was raining heavily and the light was poor it could become a bit more difficult as you battled to hear over the rain belting down all the while and doing your best to keep the code book dry.

  1. Z Special Unit was a joint Allied Special Forces (SF) unit formed during WWII to operate behind Japanese lines in South East Asia [2]. It is also known as Special Operations Executive (SOE), Special Operations Australia (SOA) and Services Reconnaissance Department (SRD).  Wikipedia

I deployed to Malaya shortly after I gained my Patrol Sig qualification and I was surprised to learn I was the only person in the 5 man patrol who could send and receive Morse code. This was unusual as there were generally at least 2 patrol members who were qualified so I was a little apprehensive at first with this new found responsibility.

Doing battle with the man made (QRM) noise was the most difficult bit with a set that had 5 watts output. It was very difficult to get above the noise and we sometimes spent a couple of hours getting a routine message through that gave our grid reference and advising HQ we had nothing to report.

We always chose a good secure place to send communications from and sometimes this is not the ideal place to sight an antenna in dense jungle. In the dry season in Malaya the jungle floor can be covered in very big dry leaves similar to giant Kellogs Corn flakes making it difficult to move quietly. There have been sightings of animals such as tigers, (rare now), elephants, the usual reptiles, and around the bamboo in the waterways it is not uncommon to find wasps that can become very angry when they are disturbed. One of our patrols encountered "a large cat" circling their overnight LUP (lying up place) though it was never positively identified. It was growling and very smelly.

We found evidence of fresh elephant poo when following the creeks although we never sighted any. An SAS soldier was killed by a rogue elephant in Borneo in 1965 when it rushed the patrol and crushed him against a log. Intelligence briefings given to the squadron made no mention of elephants in the area.

The AN/PRC-64 set was used as the primary means of communication for SAS patrols in Vietnam from 1966 to 1971. Prior to that, the 510 set was used in Borneo and I believe they were far from ideal for jungle operations where it was very difficult to keep equipment perfectly dry.

The rubber plantations are great places to hoochie up in as the trees are nicely spaced and it is very easy to put your hammock and shelter up but it is also the ideal habitat for everything that is known to crawl, jump or bite, including a large scorpion that lives in a shell, spiders of all types and a millipede that produces an acid that can cause a large raised welt on unprotected skin.

In 1995 I put a bid in to purchase an obsolete AN/PRC-64 set from the Department of Defence in Broadmeadows. I was successful in picking one up in good condition for AU$50.00. I have kept the receipt, as a few of the people I served with have visited me over the years, including my former Commanding Officer, who may have been a bit inquisitive about why I would have a military radio in my shack!

Modern military radios have changed dramatically over the last 25 years and are beyond the scope of this article. They have a much better capability for sending secure messages over very long distances in clear and with less down time therefore reducing the vulnerability of a patrol on the ground.

John Trist, VK2 MOP 1
Deniliquin, Australia

  1. Published in June 2014 in a publication of the Australian Branch of the Royal Naval Amateur Radio Society (RNARS-A). Reproduced here by kind permission of the RNARS-A. December 2014.

  1. Wikipedia, Gold Dust and Ashes
    Retrieved January 2015.

  2. Wikipedia, Z Special Unit
    Retrieved January 2015.

  3. Bob Long, Z Special Unit's secret war:
    Operation Semut 1: Soldiering with the head-hunters of Borneo.

    ISBN 9780908021109. First release 1989. 608 pages.

  4. Technical Report No. 67-01, Radio Set, AN/PRC-64
    U.S. Army Limited War Laboratory, Unlimited Distribution.
    Stanley D. Peirce, April 1967
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Crypto Museum. Created: Friday 19 December 2014. Last changed: Friday, 06 October 2017 - 13:58 CET.
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