TYPE 51 P


TYPE 51 TRANSMITTER

DATE OF DESIGN 1931
FREQUENCY RANGE 150 -1875 kc/s LF : 1650 - 13635 kc/s HF with variations for different sets in the series.
POWER SUPPLY Double purpose Generator 400V and 8V. See this file for the main power distribution and associated circuits [Morse key, aerial COS etc] 51 MAIN POWER DISTRIBUTION.pdf
TYPE OF SET VALVE
WAVEFORM ICW and CW
METHOD OF PRODUCING OSCILLATIONS SELF
WHERE USED/FITTED Type 51 is a low power ICW/CW transmitter for high and low frequencies, and consists of a L/F transmitter 4P, H/F transmitter 5P, A Modulator 8P with a Receiver B13, the whole being rack mounted. It can be fitted as a L/F or H/F transmitter complete.  In the former case, for use in Tugs and Trawlers it is known as a Type 51L [fitted with Receiver B13], but when fitted in Destroyers, as Type 51H and will replace transmitter Type 83. "D" Class Destroyers have been fitted with H/F transmitter 5PX and Modulator 8PX with a separate aerial unit. In this case the complete outfit is known as the Type 51HX [which is shown separately with its own port hole].  The Type 51L was fitted in small craft and RFA's under 1000 tons displacement.  The Type 51LV was fitted into Flotilla Leaders but will be replaced by the Type 60EV. 51LW is fitted into cruisers for fire control although it will be replaced by the Type 52FHW.  Type 51FLW fitted into cruisers for fire control will be replaced by Type 52FHW. Some old destroyers have the Type 51HV fitted for "screen wave" and for fire control.  The 51FHV currently fitted into Tribals  for "screen wave" and fire control will be replaced by the Type 52FHV.  51HW used in cruisers for "screen wave" - to be replaced by the 52FHW.  TYPE 51FHW in non-CCS ships {central control W/T system] for "screen wave"; replaced by the 52FHW.

The modulator is fitted to produce an AF tone of 1400 c/s for keyed ICW.  Approximate range in miles = 50.

Valves of the transmitter are mounted in "sorbo" to prevent damage to the valves due to shock.  Many of the Type 51's instruments are fully enclosed in an aluminium box. Click on this thumbnail to read an OED [Oxford English Dictionary] definition of "sorbo".

Click to enlarge
ASSOCIATED WAVEMETER G8
SMALL SCHEMATICS








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