941-SWB HF Receiver (NZ)

General Description

The 941-SWB Receiver is another variant of the basic HRO design. These receivers were first built in 1941 by Collier and Beale of Wellington, New Zealand for the New Zealand Post Office and were also used in commercial/military service. These sets were built to meet the requirements of the various organisations using them.

There are quite a few variants of the basic design in existence. The display receiver has been used by the N.Z. Civil Aviation Branch. It obviously has done quite a bit of work on the amateur bands later in its life and has been modified to some extent.

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Technical Data

The receivers covered the frequency range of 1.4 - 20 Mc/s in four bands, using plug in coil boxes.

Nine valves were used. There were 2 RF stages (6K7), a Mixer (6L7), Local Oscillator (6C5), 2 IF stages (6K7), Detector/Audio Amp (6R7), BFO (6C5) and Audio Output (6C5).

The receivers required a separate power supply of 6.3v (heaters) and 180vdc for H.T.

The tuning mechanism used components imported from National, U.S.A., the manufacturers of the HRO.