TRANSMITTERS & TRANSCEIVERS

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 SUPPLIES

Double purpose Generator 400V and 8V. See under Further Reading.

POWER TO FINAL STAGE.

TYPE OF SET (VALVES USED)

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 (see Type 51HX). The Type 51L was fitted in small craft and RFAs 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.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 (see Type 51HX). The Type 51L was fitted in small craft and RFAs 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. Look under Further Reading for OED (Oxford English Dictionary) definition of "sorbo". 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. Look under Further Reading for OED (Oxford English Dictionary) definition of "sorbo".

ASSOCIATED WAVEMETER

G8

FURTHER READING

Definition of Sorbo
Type 51 Mains Power Distribution

IMAGES, PHOTOS, DOCUMENTS, SCHEMATICS ETC.

Photos and Schematics

NOTES.