Posted by
SAD,SAD, GOP on Sunday, March 15, 2009 4:54:46 PM
Construction of Radio Equipment in a Japanese POW Camp
By Lieutenant Colonel R. G. Wells
Transcript
of a recording by Lieutenant Colonel R G Wells, on the construction of
radio equipment whilst in a Japanese Prisoner of War camp after the
fall of Singapore.
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It was about the beginning of 1942 when I was a prisoner of war of the
Japanese, when I was ordered to go on a working party which eventually
finished up in the Sankakan in British North Borneo. Two thousand odd
of us were in this work party and it wasn't long before we noticed the
absence of information as to the international situation, what was
happening in the outside world, and the whole camp had a real craving
to get news by whatever means. Escape parties were being organised, but
none of these were very successful. The next thing people turned to was
a means of getting some radio news, and this is where the building of a
radio set became an urgent requirement.
The
main thing, of course, was that we didn't have any components and
although we had some contacts outside which later on were helpful in
the building of this receiver, it limited our requirement to a
regenerative receiver as from a super heterodyne receiver and the
decision to do that was borne out by the results.
The
high frequency spectrum during that time of the war was fairly quiet in
that part of the world and the BBC, we hoped, would be able to be
received. This was aided by the fact that the Japanese in their wisdom
called a friend of mine out one evening to repair their radio set and
he took the opportunity, of course, to switch over to the short wave
bands, with headphones while doing that, and picked up the BBC
successfully.
That day was memorable because it was the day that the BBC broadcast the death of
the Duke of Kent in an aircraft crash. That was the only news we had of the outside world for something like six months.
The
plan was made to begin building the radio, so until we could build
components, there was nothing much we could do. A look at the circuit
diagram of a regenerative receiver indicates a number of capacitors -
about two or three are required -low capacitors to make the oscillating
part of the system work, and in fact from memory we needed in the grid
circuit at least one ".01 microfarad" capacitor and there was no chance
we could get this anywhere, or any other components.
So
we hit upon the idea of taking some tin foil or aluminum foil from the
lining of the tea chest from which the Japanese supplied with the rice
rations, then by the well known equations for calculating capacity and
the relationship of the surface area and
spacing of the plates, we built a capacitor or, at least, I built a
capacitor which according to calculations should have been about ".01
microfarad."
If
I could put an aside here, I built a replica of this capacitor some
years ago, and it went out to Simpson barracks where we had some
friends in the testing laboratory, and with great excitement the
Warrant Officer concerned said, "We will see how good your calculations
were"; so he put it on his equipment which was accurate to many decimal
points and read on his display unit, ".009 microfarad", so we thought
we were pretty good.
I
said "Touché" to him because he didn't think we could do it. I made two
or three of these, and I still had one of them that would work if I
built the receiver again, which I have been thinking about doing,
except there is always something else, like a lot of other projects
which one has as one gets older.
The
resistors were another problem. We found out that we could use the
impurities in some of the tree wood and the bark, particularly cinnamon
bark which was available by getting through the wire only about 2 feet
and we could normally pinch that while the Japanese sentry was moving
around.
We
used a piece of string with the material rubbed on it from the burning
of the cinnamon bark with some impurities in it (we didn't have a
chemical analysis); we weren't very fussed because most grid-leak
resistors were about a megohm or thereabouts and we had no means or any
way we could measure a megohm, so it was largely a trial and error
thing to see if it would work. We made a number of these bits of string
and tied them round different things to dry them out to get the thing
going. Eventually about an inch, three quarters of an inch to an inch,
was about the right order of things to get about a megohm resistance.
They were the two main things.
Now
the things we couldn't provide, couldn't do. We had to make coils; they
were largely trial and error, one could calculate the inductance of
these if one had access to some means of measuring the wire gauge and
the space between them. So that was largely a trial and error business.
The
two biggest components, or two biggest requirements, were we needed
some
headphones and we needed a valve, and I thought that the rest could be
made locally with a bit of luck. On the question of the headpiece an
outside contact smuggled in one headphone, which was better than no
headphone, and a valve - no valve holder but one can't have everything
in this life.
The
other trouble was the power supply. The Japanese main around the camp
which provided the power was 110 volts roughly according to the power
station meter which we couldn't help but see, because we delivered the
wood there while the power station was running; I switched over when no
one was looking and the frequency was about 60 Hz, not 50 Hz as we
thought, not that this worried us anyway but to know that it was
manageable.
So
two problems remained for the power supply. The first one was the
A-battery or low voltage supply necessary for the filament of the
valve. We started with a couple of dry cells, but these didn't last
very long and we had to make something then. Through being friendly
with the pharmacist with the party, we got some potassium bichromate
and made up a bichromate cell, which is probably well known in the text
books but not of very practical use. It's fairly hungry for zinc and it
needs some sulfuric acid which one can't throw around or hide easily,
but it served for some time and was
quite successful but, in the end, had the operation lasted very long,
we would have been in trouble for that. Two of these cells provided
about 3 volts to 4 volts, and 6 volts was a bit too much because each
cell was running at a bit over 2 volts, about 2.2 volts.
The
biggest problem was a rectifier to rectify the AC into DC without
dropping it to a low voltage, because remember in those days we needed
high voltages for the B supply, or anode supply, but in these days we
bring everything down to small DC voltages; we needed to get them up as
high as we could. That was a partial failure in that using aluminum
foil again and oxidising one piece of it, or length of it folded over,
with some weak acid and then using the two electrodes, one of clear
aluminum and one of a
zinc salt and aluminum, we could make a rectifier.
We
wouldn't be so audacious as to call it a rectifier now, because it had
a reverse voltage of something like 30 or 40 volts, which wasn't
exactly ideal, but for DC we had no option. The result was that I made
a bridge rectifier but the only problem was that after 15 minutes the
electrolyte began to boil, so it was really passing current in both
directions but a little bit more one way than the other. So a single
cell, an extra rectifier cell, was the only way I could close this down
a bit, and some smoothing.
This
we achieved with part of a fish plate from the railway line which was
being used at the aerodrome to move the dirt from one place to another
by man-power, about six men on these, and the odd fish plate used to
disappear anyway for various reasons.
I
dropped one off at the power station and asked the Chinese under my
breath if he could cut it into three little sections which he did, he
didn't want to know why.
Then
again using some palm oil and some bee wire which was in fairly
plentiful supply, which we stole - it was a bit risky because the
Japanese were cultivating a couple of beehives outside the wire and of
course this wire used to disappear for various things unrelated to
radio - and we put the palm oil along the wire stretched out and rubbed
this palm oil on it, thickening it with a little bit of flour and then
heating it; the flour bound the palm oil together and formed a fairly
good insulation over the wire.
Good, but lucky, and with a lot of traveling.
I
should come back to the capacitors on that, because we had to insulate
the layers of those which we did by putting a layer of newspaper (a few
people had newspaper and various things, for other reasons than
newspaper of course, but then we had no other toilet requisites in the
party) and by soaking this in some coconut oil we could insulate each
layer after we wound it, and with a piece of this bee wire - we had
something like fifty feet of it - wound round this part of the fish
plate, we made a fairly good choke coil. And then a bigger capacitor,
which was no trouble, having had
success with the small one, to just wrap as much tin foil as we could
round another
sheet of newspaper which finished up about 18 inches long by about
three quarters of an inch in diameter. We didn't even try to measure
the capacitance of it, because we couldn't do anything about it anyway,
except put more wire on. And that in effect was a fairly good
rectifier, a very dangerous one because we had the 110 all right but we
had a bit over that by the time we had rectified it, and we don't know
because we had no means of measuring it.
Finally,
the valve; we joined the valve by winding the clean little bee wire
around it and then plugging it with any insulating material we could
get to make it stick, - no valve holder, of course. So eventually we
produced a receiver of sorts, except it wouldn't oscillate. We tried
building more, another choke coil, and this went on for ages; there was
no possibility we could get this valve to oscillate. I think it's
recommended according to a friend of mine who had an amateur license,
he thought that about 120 volts was the best we could get and there was
no way we could get that by
trying to smooth this any more. So the only avenue open was to bribe
one Chinese
working at the power station who was very much our way, and of course
in those days was a nationalist Chinese.
The
capital of China in those days was Chungking, and I told him we could
get him some overseas news from Chungking if he would slowly wind his
field coil power up on the generator every night starting at about 9
o'clock bit by bit, and get it up to about 130 on his meter. He
understood, and after that I said half an hour to drop it
again, very quietly and slowly because it may affect the lights
"....and you no speak about that because you get chopped, you know, and
we will give you Chungking news...."
This
was duly done and for about six months we had reliable communication.
The first trial on air had too much hum, and we had to modify a few
things two or three times in attempts to get it right, and in the end
we had a workable situation which was worth exploring.
Capacitors
right, choke coils right, one head phone, we had some old rag
so we tied it round the head and tied it on, or string, or whatever we
could
get. With the hope of recording something we took some paper, which
wasn't in plentiful supply, but the odd piece of paper we could get.
Running notches down the left hand side, about a quarter to a half inch
apart down the paper, and bending it over so that these little pieces
stuck up in the air, and in the pitch darkness one could then put the
headphones over one's head with eyes looking out for possible
interruption by the Japanese - we had some lookouts, or cockatoos as
the Australians called them, around the place to warn us at the
oncoming of the Japanese - and with great trepidation we heard Big Ben
chiming one night. Of course only one of us heard it but we were so
full of enthusiasm.
It
was the BBC all right; it was quite a clear signal but it was somebody
talking about growing hops in Kent. This broadcast went on for
something like three quarters of an hour without any interruption, but
ultimately the signal faded out and I was very annoyed. I was asked the
next morning by my senior officer what was the
news, and I said "we've got good news; I can't talk here, come this
way." So he came along and said "what's this news you're talking
about." I said I didn't actually hear any news, and he became very
annoyed with me and said what the hell did I mean, and I said "if the
British primary producing experts are capable and able to spare the
time to talk about growing hops in Kent, Britain must still be alive
and floating with their thumbs up, and as far as I'm concerned that's
the best news I could hear!"
That's the outline and maybe there are some questions I haven't covered properly.
BJ: The first question I would like to ask you is: What did you have in
the way of tools, if any, and how did you connect the components of the
wireless without, presumably, a soldering iron?
RGW:
No soldering iron, no solder of course, and no other system really
available but to twist and wrap with some coconut oil paper, or
cardboard or
something, and very gently lift it. It was on a platen of wood we
obtained
somewhere; it was about a foot by a foot or something, so we just
mounted
the components on that. A meat skewer on the capacitor - oh, we had a
capacitor too, a capacitor, a valve and a headphone, which were
external to camp components we had. We didn't have any tools at all,
except someone obtained the use of a sledge hammer - for what purpose I
don't know because one of those would not be needed to escape; other
than cutting up the soft iron of the fish plate which was about the
only reason we needed anything, the rest were just twisted wires. We
just wanted to get one usable
because we didn't know whether it might be blown up or captured; we
weren't worried,
the main thing was initially a short term aim (as well as a long term
aim) that it might last. Fortunately, it lasted for over a year -
sixteen months until the arrests took place, but that's another story.
BJ:
Can I just ask you - the components for the low voltage battery cells
that you produced, where did you get all the components from?
RGW:
Well, zinc wasn't hard, there was some sheet zinc lying on the
aerodrome and we pinched quite a bit of that because that would be
eaten away during the use of the cells for the low voltage. I don't
know what would have happened if that ran out. I think someone produced
two lantern cells which did for a while, but it was mainly on this
home-made cell system, which wasn't efficient but nowhere near as
inefficient as the rectifier was. We must have been consuming... Ah
Ping said he had to turn up a lot of power to keep the lights what they
wanted. We were dispersing such an amount of power in this four test
tube rectifier for the high tension.
A
variable capacitor was another component we had to bring in. We
couldn't make a variable capacitor, it was impossible. We had to take
two plates off the one we had to get a high enough frequency. Yes, I
can't remember why we didn't go up a bit in inductance; it was largely
a trial and error business really. Except that in a regenerative
receiver you had some idea when you were near a station because the
receiver was so sensitive as all regenerative receivers are.
It
had a piece of meat skewer type wood which I had a hole drilled in by a
pen-knife, and we glued this in with some of our glue or something,
into the capacitor shaft so that we could tune it by holding a little
stick across it, fixing it at about six inches because one couldn't get
one's hands any closer to the set because it was in a state of very
near oscillation where the maximum sensitivity is, just before it
bursts into oscillation. With a fairly clear HF band, it wasn't long
before we knew roughly, by putting a couple of marks on the stick,
where it was. We knew that the Voice of America was due for a
transmission and I don't think we ever knew the frequencies because the
BBC didn't announce frequencies, they just came on the air and
broadcast.
BJ: What did you use for an aerial?
RGW:
A clothes line. All the huts had a clothes line of some sort so we just
took a thin wire from that and wrapped it round the edge, knowing that
a normal sentry wouldn't take any notice of it, and we just dragged
that across the side of the hut and brought it in, and the people with
our permission would put their loin cloths out and hang them over this
when they washed them so it looked as if it was being used. The toilet
in the sleeping block was a hole in the ground and it was verboten to
be used by anybody except to put our radio set in when it wasn't in
use; everybody
respected our wishes in that regard!
I
think the best thrill was, well two or three thrills, which were
momentous I suppose and of great excitement, almost excitement of
crying with excitement, and the first was I think when we heard a full
news bulletin of something like 400 aircraft over Dresden or somewhere,
pounding the place to pieces; we were very pleased about all this. But
from the land point of view, from the beginning of '42 I think, I can't
remember, but sometime just before the Battle of Alamein, and we heard
some of the troop movements in preparation for that. The bulletins in
those days were fairly long and gave a lot of detail.
Unfortunately
the first lot of rectifiers blew up about 2 days after this so we were
out of business for something like 5 or 6 weeks. Of course, the rumours
started to flood in as to what was happening, what wasn't happening,
the war would be over in 5 minutes and all these mainly optimistic
things; but there were a few super-pessimists who said we would never
get off the island, and would die there, and that sort of thing. But
the thrill, I think, was when reception was restored again and we had
to do another little bit of fine tuning because everything you changed
seemed to affect
something else; the whole thing was very sensitive and wouldn't have
stood up to
present day quality assurance bump tests!
So
back there on the first night we missed the BBC for some reason, and
the next thing was the Voice of America which had a headline which ran
something like this: "The war is over in North Africa, Rommel is
knocked to pieces, he's out of the Middle East and the Middle East is
finished, the future for this and that ............." That was the end
of the American news in about three sentences! No other detail, so I
said we would go back at about 12.30, and hope that Ah Ping hadn't
pulled the voltage down too far, to see what we could hear.
Again,
the BBC was a little low but it suddenly came quite bright and lifted
in volume, and Big Ben chimed again and there was a voice in the
wilderness calling. It was a lovely sensation to hear Big Ben playing
in those days, and every time I hear it now I become excited. The
announcement, initially in a most depressing vein, described all about
the 8th Army's movements, and it was here that it did this, and this
regiment drew up and did that, on and on this went for something like
15 to 20 minutes, and we tried not to follow it because we had our eyes
on too many other things, look-outs and so on. But a lovely flow of
English and if you had a tracing board you could have traced out
exactly where everything was in situ, but of course that wasn't the aim
of our exercise which was to get news. At the finish of the news the
polite sentence said "It must be considered now that as all resistance
in North Africa has been overcome the Allies victory must be "assured"
or something like that. And that was all he said, but he took a few
minutes to describe everything that happened, so you had a clear
picture. But the Americans seemed to be creating for a
public that just wanted the headlines, three headlines and that was
all; no other
interest in anything else. That was one of the happy moments of the
system.
We
had the problem, of course, of writing the news because naturally a lot
of people wanted to know it and a lot of people could be told it
without its origin. This is why we used the piece of paper we took with
us (Gordon Waite and the other officer who used to share some of the
work), and as soon as we heard about 30 bombers over Dresden or
something, you just put 30 BD, or B for Berlin, and feel the paper down
when you felt it coming to the end, and pick up the next little bit of
bend and write along that in the pitch dark, hoping that you've got
something in the morning. Surprising how legible it was, just triggered
a couple of words like that. Unfortunately, I was in deep custodianship
with the Kempitai when the Atom Bombs were dropped and I didn't hear
that news on the BBC; it was relayed to me. We didn't keep these
things, of course.
Getting
off the technical side now, the radio set didn't betray itself. Some
criticism could be levelled at us I suppose. We trusted too many
people; we had no intelligence training then, of course, or anything
like that and we were inclined to trust every Asian we met who smiled
at us and who said he was one of us. Anyway, while this was going on at
the aerodrome and once the troops heard, we had to tell the troops the
good news of course. We said we had heard from an unknown source that
the war is getting better, or something like that - we had to give them
a sanitised version. It was probably all they wanted but, naturally,
two or three senior officers
wanted to know as much as they could because they may be the ones who
would have to
take some decisions one day about it.
Unknown
to us an Indian - I don't like saying this and I'm not being racist, it
could have been any nationality - blackmailed a Chinese who was helping
us on the aerodrome picking up bits of iron for us and various other
things. He blackmailed him but the Chinese wouldn't talk, so the
Kempitai arrested the Chinese and put him on a rack; he mentioned in
the course of his cries for help - which was not a nice thing to think
about but I don't blame him - he mentioned Captain Matthews and a
couple of other people; I think I would have done the same thing at
that stage.
The
Japanese then decided to make a raid on the camp, which they did, and I
was then charged and taken away by the Captain; he wanted the receiver
and I gave it to him in the end after a lot of leading him round the
camp with his soldiers. I could almost laugh at some of the things that
happened. He must have told them he was looking for a radio set; a Jap
soldier came running up to him with a piece of metal which looked like
a piece of horse harness or something; the Captain almost kicked him
and told him what to do.
So
in the end I decided that I couldn't talk to anybody before the rest of
the troops on this parade ground, and I felt so conspicuous. He walked
back and
said "Are you going to tell me because we want the wireless set?", so I
said "Yes, I've just thought where it might be". So I went across and
told him where the hole was, and they dug the hole up and, of course,
there was the transmitter. He said "Ah, you've been sensible at last",
so he took the transmitter and they took it away.
From
that day on, I was worried about this because I knew the receiver was
OK and the troops would be happy about that; they would still be able
to get news. And then he took me up to the platform where he stood and
addressed everyone. All he said in English was "You all look at this
man, you will never see him again" and led me off. I had a sort of a
dying wish, going in on the vehicle to Sandakan to be interrogated,
that somehow or other this set could be preserved and, of course
unknown to me, it was. They continued using it but not until after
about a week or so - their nerves were a bit shaken. But they used it
for some months afterwards until the big moves
came and it was a successful source of morale lifter.
During
the trial, that was when the shock came to me when this transmitter was
brought out by the prosecution as evidence that we had been using a
receiver, but the Court accepted it. It was never mentioned after that
because had it been, I don't think either of us would have been alive,
because we had planned to get some crystals from the Philippines and
try and fit them in this set then we could call them on CW and give
them some news about ourselves.
But
we did get some news by other means, via an agent taking a sandalwood
vessel across, that the British and Australian authorities knew where
we were, and it was proved at the end of the war that they knew exactly
where to come for us. They had guerrilla parties in behind the lines,
but they couldn't contact us and they had to watch some of our people
just die virtually, because they were there and there would have been
trouble otherwise.
BJ:
Could I just take you back and ask you to fill in a few details about
the transmitter. You talked a lot about the construction of the
receiver and I would be very interested to know where the transmitter
fitted in to this; were you developing that alongside?"
RGW:
"No, the receiver first; we had that, and then we started the
transmitter as a rather low priority of course, but one it would be
nice to have. I had finished the two 6L6G's to make a push-pull
amplifier that was the RF output to be, and the oscillator, and we had
the capacitor but were missing a few more components and that was about
where we were. In other words, in the course of events, had he been an
expert with some sort of knowledge of electrical engineering, we would
never have got away with two 6L6's sitting up on a block of wood with a
few capacitors and things
hanging on them, but obviously the Court Martial officers were normal,
without disrespect to Infantry Officers, and they had no knowledge of
telecommunications.
BJ: Again, the valves you used in the receiver were...?
RGW: Only one, that's all we had, which was brought in by Mr Mabey. He
smuggled in a pipe to me, a smoking pipe, with some tobacco. Lovely
gentleman. Unfortunately, I never had long with him, he died soon after
being arrested. His widow lived at Hove with her sister; the two are
deceased now.
End of recording.
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