CHAPTER 7.


THE RADIO



The radio, that most important item, was a new type to me and I spent some time learning to use it.  It was an RAAF type, designated ATR4a, and I very quickly realised that it was going to be ideal for the job.  All up, it's weight was about 30 lbs. and came in three tin boxes; one, the largest, for the transmitter-receiver; one for the battery and plug in Morse key and microphone and a small tin box for the few spares — mainly peanut valves.  Why the mike, earphones and Morse key were contained in the battery box was a bit of a puzzle until I found that there was a speaker provided in the radio container. This totally unnecessary component — at least I thought it was unnecessary — took up a considerable amount of room which could easily have provided space for the mike, key, etc.  The extra space then provided in the battery box could have been used for the radio spares thus cutting out one container.


The top cover lifted off and revealed the speaker and the meters that gave a visual indication of power output and battery condition plus the plug in points for the crystal oscillators, key and microphone.  There was no place provided for message pads and code book and pencils though I had already made up my mind that the message and code books, for security reasons, would not be left in the radio compartment but carried in my own pack.  The two containers, radio and battery pack, were normally connected by a cord when in use but, this could be removed for carrying separately.


The whole instrument inside the case had been well and truly waterproofed and was guaranteed not to give trouble in areas of heavy rainfall and humidity.


In those days, before the advent of biros and the difficulty of providing a supply of ink for a pen, indelible pencils were preferred to ordinary lead pencils because of their resistance to accidental erasure, etc.  There were six pencils in the pack and they would be more than enough.


The microphone was fitted with an on/off switch, which was called a 'pressle switch', and was connected via a plug and cord of about 4 ft. in length.  The Morse key which was normally jacked into the top of the set could be lifted out by its cord connection and placed anywhere convenient such as a stump, pack, or whatever was available.  The whole outfit was designed to be carried on the back and was almost a load on it's own.  It was powered by dry cells and had an output of about ten watts.  I knew that such a small output meant that care would have to be taken when erecting an aerial, especially in heavy jungle, and had already decided that a half wave Wyndham, or something similar, should do the trick.  Even being on the wrong side of a hill, with this low signal strength, would make transmissions difficult, if not well nigh impossible at times.


Having previously used radios, with a thermionic valve oscillator controlling frequencies, I was well aware of their problems.  Changing frequencies with this set, unlike my previous radios, would be simple — just a matter of flicking a switch from one crystal to another.  No more fiddling tuning. It was most reassuring to see this set was well supplied with these plug-in quartz crystals which meant it would be very stable and not suffer from frequency wander if handled a little roughly.  This was indeed a big plus as one of the native policemen would do the carrying.  Our working frequencies were:


(1)6900 m/cs from 0700 hrs to 1930 hrs daily.

(2)4101 m/cs from 1930 hrs to 0700 hrs daily.

(3)4315 m/cs for communication with supply plane.


Callsigns were:-


Ours:  8PV

Link:  4LF


The link station, 4LF, was to be situated on the Idenberg River with Capt. Miller and his two signallers.  The schedules were to be twice daily at 0730 and 1615 hrs or as near that time as possible.  The link station was to keep a full 24 hour watch and if necessary could be called at any time.


Our link was also to be an outstation of the AIB, with the callsign, VIV, at Finschafen, some 700 kilometres away to the east, and all our messages were to be sent to 4LF and then passed from there to Merauke, 500 kms south.  Any intelligence gathered had to be passed to ALAMO FORCE at Finschafen, and after the invasion, to the Task Force.  Signalling these distances, especially over the high range to Merauke, would be beyond the range of our small set and we could only hope that our link, 4LF, never ceased to function.


It all seemed pretty straight forward and I was sure the radio would be quite satisfactory over the required distance but wasn't particularly in love with the callsigns as they seemed to be too long and cumbersome and I thought we could well do without the numeral preceding the letters.  I made a note to talk with our link about dropping the numeral when calling.  Also, both the call signs would have been much better reversed; i.e. 8VP and 4FL as they would have been so much easier to send and recognise, especially if there was any interference, as there was bound to be.  All radiomen know that, if one is using low wattage transmitters with consequent low signal strengths, interference and static are the biggest enemies of clear reception.  To me it was patently obvious someone ignorant of signalling by Morse code had allocated the callsigns!


The code to be used was called a "BULL" code and was a double transposition type and easy to handle — or should I say — an operator sitting at a comfortable desk in a good light would find it easy to breeze through the encoding of a message using this code?  However, as I well knew from many a past experience, I was to find during the next few months that, quite often, encoding the simplest message would be extremely difficult, especially late at night, when my only protection from the rain would be a leaky groundsheet, shakily supported on four sticks, with a feeble light coming from the flickering flame of a stub of candle!  It was on these many occasions I envied the link station, sitting back in their canvas chairs in reasonable comfort, with the rain drumming on the tent roof waiting for my transmission and wondering why my message was later than the scheduled time!


Big time Morse operators will always say that the code is just like another language to learn, and so it is, but a lot depends on conditions!  In a well lit office equipped with air conditioning and all modern aids one can read Morse at speeds of 20 to 25 words per minute quite comfortably.  But trying to do it in the aforementioned jungle conditions with a small transceiver when you are at the mercy, not only of the weather, but atmospheric conditions which cause all sorts of static and, not to mention, other foreign transmissions which insist on intruding on your receiving frequency, it just becomes plain difficult!


I was well aware of all these problems having had considerable experience with wireless in tanks in the Middle East and infantry pack radios with the 7th. Division in New Guinea.  To digress a little further — and after all this is a story of my experiences — on my former unit's way home to Australia, in early 1942, from the M.E., we travelled in the Danish motor ship "Sophocles" and they were short one radio operator and on the call for volunteers I was chosen.  It was, for once, an easy way to earn five shillings a day!  The lighting was good, the chair comfortable, and the receiver an excellent and very powerful model.  What more could one want? It was relatively easy to copy 500 groups of incoming messages which ranged from 15, to sometimes 20, words a minute over a period of 30 to 40 minutes.  (To the uninitiated, a group of five letters is counted as a word).


Also, my point about the call sign being easy to recognise among the welter of other signals coming in was borne out by the Merchant Navy call sign of GBMS (Great Britain Merchant Service) that was used on the ship.  Bear with me and I will endeavour to show you how an easily recognisable call sign means such a lot to the identification of an incoming signal.  The code for GBMS is read as DAH DAH DIT, DAH DIT DIT DIT, DAH DAH, DIT DIT DIT.  Try saying this by emphasising the dahs slowly and the dits as quickly as you can and you will see immediately it has a certain swing and rhythm that can be easily recognised even over intruding static and other transmissions.  This is an excellent example of the type of easily recognised callsign I wanted and just reversing our proposed callsigns would have made for much the same easy and quick recognition.  Once the callsign is recognised and the pitch of the Morse note is fixed in your head you are on your way to successful copying.


The reader may think I am going on about the radio but on these operations it is fair to say that the signalling is most important and lack of communication with base almost certainly means disaster.  Strict adherence to scheduled transmission times is also extremely important to the success of any operation and, as information sent concerning enemy movements was the main reason for this operation's existence in the first place, we could not afford to have the radio out of action at any time.  And don't forget we also depended on the radio for food, etc as well.  Without it we would starve!


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