Model 50 Hand Cranked Generator

Model 50 Hand Cranked Generator

General Description The generator was packed in three boxes which were inside a wooden chest. Box Number 11 held the generator, which was made in February 1972. Box number 2 had an Accessory bag and contents and another canvas bag which I think may have been for wet cell storage batteries. Box number 3 held the generator platform which collapses for travel and opens up for use. It unfolds and has a seat for the operator. The accessory bag held the power cable, a set of jumper cables which were to be used for testing the circuit board when removed from the generator during repairs, a box of spare electronic components which were power transistors and diodes in case the ones in the generator burned out, a can of grease for the generator bearings, and instruction manuals and equipment service logs.

Model 50 Hand Cranked Generator Folded

Once unpacked, the set requires some assembly. The generator is held to the mount by a screw in rod which allows the generator to be tilted up for use or tilted down for transport. Snap clamps or screw down clams held the generator in position. The screw must be undone and the generator placed on the mount and then the rod is re-inserted and the screw is screwed into the frame. A nut on the end of the screw helps hold it in place but as there is no cotter pin, it looks like it would be one of the first things to get lost. Once assembled, the set can be collapsed and transported by one man. The main accessory bag had a shoulder carry strap and could be closed keeping its contents inside, The second canvas bag had a centre flap that looked like it was to hold something in the bag. When the top flap was closed, the sides were open. Anything other than a box like item would fall out which is why I suspect it was for a wet cell battery. I may be wrong on this.

Generator Electronics
The generator must provide AC voltage through three sets of windings. This is passed through six diodes which convert it to DC which is then fed to a voltage regulating circuit. The electronics are mounted on a Printed Circuit board which can be removed for repairs and testing using the jumper cable provided.
There are two switches on the top of the generator which are under a small cover. One is marked Volts or Amps. It is shown on the schematic. The other switch does not appear on the schematic. A meter is also on top which indicated the voltage being generated and also amps. I assume this would be used to determine the current the radio was drawing when transmitting or receiving. The generator data plate indicates 2 Amps at 25 volts and 1 Amp at 28 volts

Tactical Employment of the radio
The Chinese military is not as dependent on radio communication as the American army is. In many cases, the subordinate units have a receiver only so they can listen for instructions but can not ask questions or respond. This set appears to have been designed for use at company and battalion level. It is probably a replacement for the 102 E sets and the XD 6 sets.
Without having access to a technical manual or a battery box, it is not possible to actually determine if this set can be used as a portable set. I think it can used as a back pack set. The headset/mike cable tends to support the fact that it can be used in this manner.

Strengths and weaknesses
Principle strength of the set is it's compact size, light weight and rugged construction. The headset/mike cable and the power connector cables are plug in and have a hold down screw which make them almost impossible to accidentally pull loose, unlike prior sets.
Major weakness of the radios is the fact that they are not easily repaired. Removal of any of the modules would require considerable labour. Replacement of one or more of the tuning modules in the receiver would require removal of all three so that the shaft for the rotary switches can be withdrawn. In addition, while there are three separate modules, in the receiver, they are all built on one printed circuit board. Any major damage to a tuning module requires replacement of all three. It is my opinion that this set is basically a throw away set. If anything breaks down, throw it away and get a new one.
The transmitter is a bit easier to work on but still repairs are labour intensive.
The headset/mike cable has a 1/4 inch thick cable connecting the mike to the radio. The headset, however, has a very thin cord which looks like it is easily broken. The key is not the best key for a tactical radio.
The generator, while well built is on a very flimsy mount. It is obviously designed with a small stature, light weight person in mind.
The antenna loading coil is another weak area. It has a wire that connects to the various taps. This wire easily becomes disconnected, just moving the set from room to room. Walking through a jungle or any tactical situation must make it even more susceptible to accidental disconnection

Collector Value
Difficult to place a value on this set. It is not readily identifiable as part of the North Vietnamese or Viet Cong arsenal during the period of the U.S. effort during the Vietnam War. The radio set alone is probably worth about $150 to $200.00 to a serious collector. With all the accessories, such as the headset, headset/mike, key, antenna, and with a technical manual and a schematic, the set should be worth about $400 to $500 to a serious collector. With the generator, add another $200.00. This set is an interesting piece of the radio history of the Chinese Armed Forces. It is also one of the first Chinese military sets to use transistors, a step forward for the Chinese radio industry.

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