Automatic Weather Chart Recorder D-900-T

Designed for shipborne installations, the D-900-T series of automatic weather chart recorders made by Muirhead is also suitable for small airfields and airstrips.

The recorder comprises a radio receiver, FM/AM converter, and facsimile unit.

Any eight of the many World Meteorological Organization's Radio - Fax transmissions in the frequency range of 1.5 to 25 MHz may be received once the pre-tuned RF units and crystals have been fitted. An adjustable beat frequency oscillator and a monitoring oscilloscope are incorporated to allow the operator to check that the correct frequency is being obtained (and maintained) from the FSK (Frequency Shift Keying) transmissions.

The equipment is semi-automatic, the helix speed and index of co-operation (product of the drum diameter and number of lines per inch) being selected manually prior to recording.

The equipment will then start and stop automatically on receipt of the appropriate W.M.O. control signals but can be controlled manually by the operator if required.

The recording is on standard 200 ft rolls of 9“ Mufax electrosensitive paper.

Brief details from the specification include helix speeds of 60, 90, and 120 RPM; scanning density of 98 or 196 lines/in; and power consumption of 100 watts.

Here you find 29 models, 24 with images and 1 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
All listed radios etc. from Muirhead & Co. Ltd.; Beckenham