RM 31 (coded name Supertana) - General purpose field HF radio station used by CSLA in 60's
RM 31 is general purpose (universal) field HF radio station designed for different usage as follows:
RM 31-a > vehicle installation (automobilni)
RM 31-t > tank installation (tankova)
RM 31-p > infantry setup (pechotni)
RM 31-s > self propelled gun installation (samohybna dela)
RM 31-a as same as RM 31-p or RM 31-t and RM 31-s are equiped with heptal direct heating battery tubes 1H33, 1F33, 1L33 and 3L31 from TESLA. Also Hungary replacement Tungsram was used in some cases and they were direct copy of US tubes. The only final tube RL15A with coded name EV301 (original marking TESLA was 5L50) used in TX of this RM 31 radioset is different with 9pins glass B9G socket. It is pin compatible with pentode parts of the Germany RL4,8P15 tube.
The frequency coverage is 2000-5995kHz. There is 800 channels available with 5kHz steps and (+/-) 1.4 - 4kHz variable frequency offset.
Available modes are A1, A2, A3 with variable crystal CW filter 200Hz - 8kHz!
Power output: 1.5W/A3, 3W/A2 and 6W/A1 typicaly.
PSU for RM 31 - field radio station
The RM 31-a (vehicle setup) was powered from battery packs thru double rotary converter ZD-31b. (maybe more correct english translation is "electromechanical vibrating transducer" connected to 12V batt cells) Frame of 2x6V cells packs 5NKN-45 was wired to 12V going to rotary converter which produced neccessary voltages for RM 31 station in RX/TX modes.
Also manual crank generator RM 31-1 was available for the RM 31-p (infantry) setup which produced 400V when TX was ON. In the RX mode it was powered from battery packs 4NKN-10 on the back of the "man nr.2" in the patrol thru vibra converter ZV 31. In this case the RM 31-p setup was operated by "3 men" in field operation.
(The article in Czech language is already posted)
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Text copyright © Petr, OK1RP