702D AM Transceiver

When Chinese troops step into Korean War, they found that they badly needed wireless communication equipment. In one hand, orders were given to Soviet for immediate import; on the other hand, requirements were given to domestic works. The requirement for a Battalion-Company level SW transceiver was given to Tianjing Wireless Works (Works No. 712) in end of 1950. Development started in November 1950 and the shop quickly brought up prototypes in April 1951.  Its code name is 702 and saw large scale action before the end of Korea War.

The 702 radio uses two imported tubes (2П2П, later production uses domestic 2P2 tubes) and two diodes (Д1Ж), other components were from Works 712 itself and other local shops and manufacturers.  The radio consists a radio body, a 2.34-meter pull-out type 6-section wipe antenna, a 20-meter wire antenna, a head set and a backpack carrying a battery unit plus the radio body and accessories when not in use.  The radio body weighs about 1.9 kg and is measured 120x80x30 mm.  I have never seen a battery for 702 radio, but by judging the size of the backpack, it should be measured 29x14x9 cm, and weights 2-3 kg.   

The radio operates at frequency of 26.1 to 37.0 MHz, right at the border between HF and VHF.  It is powered by a battery unit with output voltage of 3V, -7.5V and 96V.  The transmitting output power is 0.05 to 0.1W and operates in AM mode.  The receiving part of the radio is a two-tube super-regenerative AM receiver.  The frequency scale has 11 numbered marks (0 to 10), corresponding to 26.10, 26.60, 27.35, 28.20, 29.10, 31.05, 32.35, 34.05, 35.65, and 37.00 MHz.    

702 radio had gone through several revisions during its production life.  Mine is a D model, the last model I believe, built in early 60’s.  I am still looking for a whip antenna for my 702 radio.