10/05/2008

Type 139 Short Wave Field Portable Receiver



Type 139 receiver started its life inside Type Eight One transceiver as the receiver portion of the transceiver. The Type Eight One was developed in early 50s and saw action in later part of Korea War. The criticism received from the troops was that the transceiver was too heavy to be carried by one foot soldier. A transceiver set was then developed with separated transmitter and receiver. This receiver is the Type 139 short ware receiver. It is stand alone receiver; and it could also be used as the receiver in Type Eight One transceiver set. This Type 139 receiver is the first generation field portable military receiver developed by China in 50s. It is in production until early 70s although transistor receiver 139A/B, 239 and 339 were all in production at that time.



This 139 receiver is a 7-tube superheterodyne short wave receiver covering 2 to 12 Mhz in three bands (2-3.8 MHz, 3.8-7 MHz and 7 to 12 Mhz). Every tube is protected by a tube shield. All circuit broad is coated with a layer of protective coating. After almost 40 years, it is still shining like new. It is powered by a 1.5V/90V Type Special 81 unit battery in its battery box or by an external 1.5/90V power source. It guaranteed a working condition with no less than 1.2/65 V power source. It still can works with decreased sensitivity when the battery power drops to 1.1/55 V.



In an operation point of view, 139 is a very simple receiver. The only things you can control are frequency, band switch, sound volume, mode (Off, CW, Voice and Voice with automatic volume control), and tune for CW mode. I find that Voice with automatic volume control works the best; it maintains the voice level to a pretty constant level. The frequency reading window is very small. There is a reading light inside you can turn on to help you reading the numbers. You need it even in day light.



I brought my 139 as part of my Type Eight One transceiver set. It was NOS, came as boxes sealed with wax with full range of accessories: carry harness and an accessory bag, full set of extra tubes, other parts like wire antenna, light bulbs, fuses, repairing tools and operation/technical manual, plus a multimeter made in 1968. My sample is made in 1973 with a serial number of 730177, which mean it is the 177th machine in 1973. The operation manual has its serial number matching that of the machine. It also has stamps from the QA, Production manger, and military representative with their real names. It is not the practice nowadays (numbered stamps replace real name stamps).



It is my first tube equipment and I heard many terrible stories about bad caps in old tube radios. I dear not do any since I don’t know much about tube radios. After almost two years, I finally get a custom made = power source (as the external power source in place of the unit battery) and some basic knowledge. I hooked up power source, a wire antenna, grounded wire and head set, turned the power mod switch on battery box to external source. I then turned the radio mod switch away from off. What I expected was that the radio needed several minutes to warm up, however, sound come off the headset immediately after I turned the switch away from off. When I switch the knob to Voice, sound of a station came out right away.



There is no other adjustment knob other than frequency turning knob, band switch, and a volume control. An antenna adjustment would be nice, and it was added in the next improved version, 139A.



This heavy tube receiver is also well thought about mobile. The power mode switch on the battery box could also be used as the power switch when using battery. There is also an ear phone outlet on the battery box, plus a small outlet at the radio cover which a wire antenna could be extend outside of radio when the radio is closed by the cover. Then it is operational while it is on the move.



The sound is very medley, very comfort. The selection is pretty good compared to my 239 and 339. It is very quiet when no station is selected. The night when I first made it working, I lessened to the Chinese World Broadcasting all night until the program ended, it was a wonderful time. After so many years, it still looks like new and works like new. Who said Chinese made goods were low quality? At least not this one.