Date of Design The Type 37S [See below to the "Where Used/Fitted" section]  was widely fitted throughout the Fleets.  It comprised of four parts, with three parts being VALVES and the other  SPARK.   The dates of design shown below in the table start in 1924 and finish in 1930, so the overall set can be considered as a 1930 transmitter.
Frequency Range
Transmitter 3K L/F 3K H/F 4H [with attachment] 6F
Frequency range 100-670kc/s & 800-1365kc/s 5770-26000kc/s 375-1765kc/s 100-900kc/s
Power supply 3kW Motor Alternator 3kW Motor Alternator Ships mains or 6V battery 3kW Motor Alternator
Filament supply 1.25kW Alternator 1.25kW Alternator  - -
Valves used 3 3 2 -
Wave form CW & ICW  ICW ICW Spark
Associated wavemeter 1492B or G9 G13 or G8 & G7 1492B or G9 1492B or G9
Approximate range in miles 800 World wide at times 10 100
Date of design 1924 1930 1925 [attachment 1930] 1930
Power Supply See above to Frequency Range.
Type of Set See above to Frequency Range.
Wave Form See above to Frequency Range.
Method of Producing Oscillations Self
Where used/fitted. Type 37S is a medium power valve set arranged on many panels.  In some cases, where H/F Panel 3KS has not been fitted, but the set has been modified to receive this panel, it is known as a TYPE 37A.  Where no modification has been made, the set is known as a TYPE 37 and the panel, a Type 3K.  TYPES 37, 37A and 37S are fitted in the Main W/T Offices of DESTROYERS and SLOOPS and in Second W/T Offices of modern classes of BATTLESHIPS and CRUISERS [1930's].
Associated Wavemeter See above to Frequency Range.
Small Schematic

See how the aerial circuit worked with either one or two operators by reading this file  37S TX 3K LF.pdf


Transmitter 3K H/F

Transmitter 4H

Another view of Transmitter 4H

Above and below the overall 37S Transmitter