The Eddystone 910/1 communications receiver is a lovely piece of kit. Join me in taking a look around this radio.
The Eddystone 910/1 is one of the rarer British valve communications receivers, manufactured by Stratton & Co. Ltd. at the Eddystone Works in Birmingham, England. Introduced around 1961–1962, it was a sophisticated, professional-grade receiver intended primarily for maritime radio communications rather than domestic shortwave listening. It was also associated with the Marconi Marine HR101, under which designation it appears to have been marketed.
One of the most interesting aspects of the 910/1 is its incremental tuning system. Unlike a conventional communications receiver, where fine tuning is generally achieved through a small variable capacitor or bandspread control, the 910/1 varies its first intermediate frequency. This provides an adjustment of approximately 50 kHz either side of the selected frequency. The arrangement offered more precise control when tuning maritime communications frequencies and was particularly useful for locating and returning to particular signals.
The second IF operates at 85 kHz, permitting a mechanical bandwidth adjustment system. The selectivity control physically changes the coupling between the IF coils. This allows the operator to adjust the receiver’s bandwidth to suit reception conditions. Narrow selectivity is useful for Morse code reception, while wider settings are more suitable for amplitude-modulated speech. The original manual also describes an intermediate setting suitable for SSB reception.
The receiver provides facilities for crystal-controlled frequency selection, alongside conventional manual tuning. This was particularly advantageous for commercial maritime installations, where operators needed to return reliably to assigned working channels without repeatedly searching across a band.
The 910/1 was designed for demanding service, with a substantial metal chassis, carefully engineered tuning mechanisms and provision for table or rack installation.
Its front panel incorporates the comprehensive controls expected of a professional communications receiver, including RF and IF gain adjustment, BFO control, signal-strength indication and selective reception facilities.