E21/R241 Station Specifications


The air-transportable, multi-channel, medium power, radio teleprinter/voice station, which comprised four air-transportable containers, seven stowage platforms and additionally, two 30 kVA diesel trailers (initially) was produced in two versions :-

(1)   TGR1(AT)26023/1 (RAF Version)
(2)   Radio Station E21/R241 (Army Version)

The station was used for ground-to-air and point-to-point communication in the high frequency band. It was equipped for transmission of ISB and SSB telephony, AM compatible SSB telephony, CW telegraphy and the dual-diversity reception of  ISB and SSB telephony, AM compatible SSB telephony, and CW telegraphy with remote or local automatic control of frequency and mode of operation.

Both versions of the station were basically similar in construction and the majority of the radio and telegraphic equipment installed was identical, differences occurring only in the terminal telegraph equipment and test apparatus arrangement in the receiver and control cabin, the mobilizing equipment for the station and the external finish.

Frequency Range

2.0 MHz to 29.9999 MHz (150 to 10 metres) in steps of 100 Hz.
Note – The frequency coverage of the issued antenna equipment was of the order of 2.5 MHz to 30MHz.

Transmitter Output Power

10kW p.e.p. (7 kW r.m.s.)

Receiver Sensitivity

SSB and CW: 1 microvolt for 13dB signal/noise ratio
AM:                5 microvolts for 13dB signal/noise ratio (30% modulation)

Communication Range

Ground Stations: 2000 miles (3218.7 km)
(full power)           (nominal)

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