TYPE 37M P


TYPE 37M TRANSMITTER


DATE OF DESIGN 1933
FREQUENCY RANGE 3000 - 20000 kc/s
POWER SUPPLY 3 kW Motor Alternator for HT and 1.25kW Alternator for Filaments
TYPE OF SET VALVE
WAVEFORM CW or ICW
METHOD OF PRODUCING OSCILLATIONS SELF
WHERE USED/FITTED Type 37M is a modification of the Type 37S.  The modification improves the performance, particularly in the matter of frequency stability on H/F resulting in a re-design of the panel Transmitter 3K[S].  The new panel is now called 3K[M].  All the wiring of the 37S remains except for those affecting the HT. Fitted into Sloops "Shoreham" class and later.

Also in this series was the basic Type 37 and the Type 37P. The 37, the original Destroyer valve set was taken over by the 37M. It used a transmitter Type 3K [100-670 kc/s & 800-1364 kc/s] self oscillator, emitting CW/ICW, 450W output with a range of 350 miles.  With it was fitted the Type 4H transmitter [375-1700 kc/s] self oscillating, ICW only, ships mains/6V battery {filaments}, output 3W, range 8 miles. In an emergency, the whole set can be used from a battery.  The 37P, also a Destroyer set, was a typical conventional set in that it had three Valve transmitters [H/F, M/F and a Low Power set] plus the proverbial Spark transmitter. However, the Lower Power set, the Type 4T was very much more sophisticated than the rest of the kit which made up the 37P.  The main sets were capable of CW/ICW, Self oscillation, power outputs 450W MF {range 350 miles}/4OW HF {range potentially world wide at times}: the Spark transmitter 100W/100 miles, frequencies 100-670 kc/s 800-1364 kc/s 3000-20000 kc/s HF and MF, and Spark 100-900 kc/s. The sophisticated 4T [100-18000 kc/s] was M.O. controlled, could be used with either a unipole or a dipole, had CW, MCW [1000 c/s tone modulation], R/T where approved. 25W/40 miles.  Power supply 20V battery supplies motor generator with 600V DC output. 4V battery supplies filaments.

ASSOCIATED WAVEMETER G7 and G8 or G56
SMALL SCHEMATICS See this file for an explanation of the modification TYPE 37M.pdf
PHOTOGRAPHS Same as for Type 37S in visual recognition.