North Vietnamese Agent Radio
In 1994 the Central Intelligence Agency declassified many documents to include an article
in an in-house magazine titled Adversary Agent Radios that was written by James J. Fauth
and published in Vol. 10 the Winter Issue 1966. Despite several errors, the article had
some good information. There were three considerations for agent radios, beyond the basic
one of signal strength (and consequent circuit reliability) which were paramount in the
design of agent radios, Security, portability, and simplicity of operation. Simplicity of
operation was the inverse of the requirements for operator skill and training. The more
sophisticated the equipment, the less training was required.
The article discussed Bulgarian, Polish, Soviet, East German and the Asian bloc which included China, Korea and North Vietnam. The Asian bloc radios were less impressive and less disparate than in Europe. All used older techniques as Soviet knowledge of high speed automatic keying systems was not shared with the Asians. The most advanced radio shown was a Chinese set supposedly made in 1963. A North Korean set was shown which was hand made and came complete in a large storage chest.
The North Vietnamese set that was shown was listed as being of 1963 vintage but I question the accuracy of the CIA's dates. The set was probably captured in 1963. Looking at a 4th generation photocopy does not provide much detail but the set appeared to be two sets, probably a receiver and a transmitter. The parts were mounted on a front panel or a chassis panel which was attached to the front panel. The "chassis" had no side panels for strength. Guessing at the size, based on the components the sets were probably 12 inches wide and 6 inches high. The "chassis" portion was probably about 4 inches deep. Both sets were mounted in a metal chest, much like some of the WW II Japanese sets. The one set that was removed from the case looked much like the Japanese TM Handy Wireless set which slid in and out of a case. While the Japanese set was a Bakelite panel attached to a wooden base, this set was made of metal.
The caption under the picture read: "A simple two tube transmitter and regenerative receiver believed to be used by the Viet Cong. The system is contained in a crude square container; it apparently operates on dry cell batteries." The CIA article said that operating from jungle base camps, constantly on the move and communicating over ranges of 100 to 200 miles the set was adequate. I tend to question that this was an "Agent Radio" in the true sense but more likely just another of their home brew sets used for all forms of communication.
North Vietnamese Signal
Intercept operations
Thus far we have dealt with the radios used by the NVA and the VC for tactical
and intelligence communication. Let us turn our attention to the radio intercept units of
the North Vietnamese Army. While in Vietnam many re-captured U.S. radios were turned over
to the CMEC by capturing units and the U.S. Radio Research units. My reaction at the time
was "interesting but so what!" I was more concerned with the latest
technological advances made by the Russians and Chinese. The Soviet IMP fully
transistorised mine detector was a technological surprise to us, a re-captured AN/PRC 25
set was not!
During the 1970's I served as an instructor at the Armour Officer Advanced Course and taught a block on Signal communications. One aspect of the course was viewing a classified film on the North Vietnamese Army Signal intercept units. The main purpose of showing the film was to show how important proper communication procedures, authentication, etc. was to a successful military operation. The film began with an introduction by "Sgt. so and so" who announced "he was Dead" but before he died, this is what happened. It showed how communications were compromised by sloppy operators. Over the years I have made several requests to have the film declassified so it could be shown to all personnel but efforts thus far to have it declassified have met with failure.
The film was based on the capture of a North Vietnamese Signal Intercept operation and the interrogation of the captured personnel. The unit was about the size of a large squad and had female personnel as well as male personnel. The women did menial jobs such as routine house keeping, were in charge of setting up and taking down the antennas, going into town for food, cooking and running messages to and from clandestine drops.
The male personnel were the radio operators and they monitored U.S. and South Vietnamese communication on a 24 hour basis. Those people not monitoring the radios were engaged in routine radio maintenance and up keep, battery charging, etc.
The NVA signal intercept units made extensive use of captured AN/PRC 25 sets to monitor U.S. radio traffic. U.S. operators were very careless in their operations and very verbose. As a result, many U.S. operations were disclosed in advance to the enemy. Once advanced knowledge of a U.S. operation was known, the intercept unit would use their 102 E or XD-6 set to alert a higher headquarters and VC/NVA troops in the area were warned and managed to escape. We bombed a lot of empty rice paddies and our infantry swept through many deserted villages as a result.
While the captured AN/PRC 25 radios worked well with the flexible ribbon antenna stuck up through the ground, the 102 E or XD 6 sets required a long wire antenna. Once it was decided that an urgent message needed to be sent, the women got out from their underground holes and erected the antenna wire. The principle radio operator would then tune up and send the message while the other members of the team took turns cranking the generator. When finished sending, the antenna was quickly collapsed and taken back underground. It was on one such transmission that one of the girls did not get the antenna down quickly enough and did not get it back underground before a patrol swept through the area. Alerted by an antenna wire in an "empty field", they made a much more detailed search and found the signal intercept unit.
These units also did more than monitor our transmissions. In many cases the South Vietnamese would call for air strikes or artillery fire missions in support of an operation. As soon as the request was sent, the NVA signal unit would come up on the same frequency and cancel the request. The South Vietnamese did not seem to follow authentication procedures and neither did the Americans.
In summary, Chinese supplied radios were the backbone of NVA/VC communication. These sets were adequate for the task and while there is nothing remarkable about their circuitry or design, they are highly prized collector items due to their scarcity. Chinese telephones show up from time to time and sell for about $125.00. Radios on the other hand command much higher than normal prices. In the mid 1980s a "Chinese Radio and Switchboard" were offered for sale at $2,500.00 for both items. At that price I did not even bother to follow up on the type. In the early 1990's a "Chinese hand cranked generator" was offered for sale but by the time I learned of it, it had been sold for about $75.00 I find that many people confuse Japanese items with Chinese and vice versa. Many "Japanese Items" turn out to be Chinese.
Disposition of Captured Radios
Those sets that were captured before or during my time in Vietnam (1967-1968) were for the
most part dismantled so the component parts could be photographed. The remaining chassis
was sent to the scrap metal yard. Those sets that were not destroyed were sent back to
test and evaluation centres in the USA.
Examples of these radios were on display at the Signal Corps Museum and at Aberdeen Proving Ground's Foreign Material Intelligence complex. There are others in various Military Museums through out the United States. Several have shown up in private collections.
As a result very few of these sets survived. In the 30 years since I left Vietnam, I have only encountered three Chinese field telephones, one Type 63 backpack radio. The Type 63 that I got was missing the battery box and all the accessories. This was not too surprising as the set had 26 bullet holes and was beyond restoration and an R 139 A transistorised receiver that I am not certain was in Vietnam during the period of U.S. involvement.
Chinese Industrial Efforts
Chinese industry seems to be better at copying somebody else's technology. Most of their
weapons are copied from Russian or American plans. During the Korean war their weapons
were copied from WW II Russian plans, most notably the PPSh 41 sub machine guns and later
the PPS 43 submachine guns, and the 75 mm recoilless rifle which was a copy of the U.S.
recoilless rifle. The few radios that were captured by U.S. forces during the Korean war
were Russian made sets such as the 10 RT used in tanks. In the post Korean war era, they
copied the Russian SKS, AK-47 and RPD Light Machine guns. These were copied in 1956 and
Chinese AK-47s are properly called Type 56 assault rifle, etc. Chinese tanks are simply
copies of Russian tanks.
The Chinese seem to have made great strides in creating a radio/electronics industry but once again, were dependent on the Russians for the basic plan/technology. As was pointed out in the CIA article, the Russian's have not supplied them with high speed keying equipment, burst encoders, etc.
Several Chinese radios have been made for tanks and one was discussed in a prior series on the Radios of Desert Storm. Other items found during Desert Storm were Chinese Silk Worm missiles so it can be concluded that the Chinese are getting involved in Missile technology. This however is beyond the scope of this short brochure.
Observations and Conclusions
The first observation that one can make is that the Viet Minh and later the NVA and VC
were strongly influenced by what they saw of the W.W.II Japanese Signal Service. The
Japanese had signal units that were triangular with a telephone section, a radio section,
and a messenger section. The Viet Minh and later the NVC and VC copied this organisation.
The Chinese were also impressed by radios that they got from W.W.II Lend Lease and items captured from the Japanese. Preferring the US design radios, they copied their 102 E set from the US SCR 694 radio. They also liked the idea of a volt meter on the hand cranked generator used by the Japanese so they added that to their radios.
When they got the technology to make sub miniature tubes such as those used in the AN/PRC 6 and 10, they liked them for the smaller size. However, unlike the American versions which had tube sockets, the Chinese simply hard wired the tubes into the circuit board. With the high pay scales of electronic technicians in the United States, you do not want a technician spending a lot of time soldering tubes in and out of a circuit. On the other hand, the Chinese workers who were paid about 50 cents a day and a bowl of rice could be used to solder tubes all day long. That was cheaper than making tube sockets. It is also highly probable that they did not plan a large logistic support facility for radios. If a set broke down, throw it away and get a new set. Again, labour being very cheap, the radios cost less to make than they would if made in the United States.
The Viet Minh used what ever they could scrounge from captured stocks of W.W.II material. Japanese and German weapons were the predominant small arms as well as some Russian designed/ Chinese made copies. There is no reason to think communications equipment was any different. To the best of my knowledge no Japanese or German radios were captured and by 1965 most radios came from China. Any radios captured from the Japanese may have been used in training in North Vietnam.
The North Vietnamese Army, as the Viet Minh became, began to resemble a modern army with modern equipment as early as the late 1950s. As Chinese radios became obsolete in the Chinese Army, they were sent south to Vietnam, in much the same manner as the Russians supplied the Warsaw Pact nations with their obsolete radios. North Vietnam did not develop an extensive electronics industry, preferring to rely on foreign aid from other communist countries. The only notable exception was the VTS-2 radio.
The Viet Cong, as the South Vietnamese communist insurgency was known, evoked much
sympathy from the Americans despite being the "enemy". This was usually based on
their inept performance on the battlefield. One remark made about them was that no matter
who won the war, they would be the losers. They were, however, very resourceful people who
made much of what they needed, such as rifles, pistols, mines and hand grenades. Radios
were no exception. The various "ammo can radios" attest to this fact. Most seem
to have been made from parts taken from junked commercial radios.
Asian military forces, unlike European and Western armies have been predominantly infantry
forces. The requirements for extensive radio communication that is found in an armoured
force does not exist in most Asian armies. As a result, they do not have as many radios,
do not have an extensive radio manufacturing capability and therefore have less radios.
This is one reason why there are so few VC/NVA radios in existence today.
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