TRANSMITTERS & TRANSCEIVERS

Type 641 Transmitter

DATE OF DESIGN

FREQUENCY RANGE

HF 1.5 to 24 MHz as simplex transmitter receiver.
HF 1.06 to 27.999 MHz (Receive only).
MF 240 to 525 kHz (Receive only).

POWER SUPPLIES

100 to 130 V or 200 to 260 V, 50 to 60 Hz single phase AC, 580 W In Use, 260 W Ready, 680 W during Tune. 115 V or 230 V AC or DC for anti-condensation heaters, 50 W each for 100 W Self-tuning Amlifier and Antenna Matching Unit, 70 W for Drive Unit receiver. Also 300 W for a conditioning heater in the AMU.

RANGE IN MILES.

TYPE OF SET (VALVES USED)

WAVEFORM

Modulation AM.
Transmission - CW (1 kHz tone keyed in USB) - MCW (1 kHz tone keyed in USB and carrier) Telephony.
Supplementary Characteristics: SSB (or ISB) Suppressed Carrier. SSB (or ISB) Pilot Carrier.
Compatible DSB (Carrier and USB only transmitted)

ASSOCIATED WAVEMETER.

METHOD OF PRODUCING OSCILLATIONS

WHERE USED/FITTED

To provide an automatically tuned 100 W HF transmitter receiver for Emergency use and for operational use in Integrated Communications System State 2.

FURTHER READING

PHOTOS, SCHEMATICS, DOCUMENTS

Details of Transmitter Type 641.
Photographs of Type 641.

NOTES.