General

The single sideband equipment type SSR2 has been de signed to be used in conjunction with the type CRD.150/20B receiver to form a Triple Diversity, Single Sideband Receiving Equipment having facilities for the reception of both the upper and the lower sidebands.

The single sideband ,method offers very definite advantages over the normal or double sideband method of wireless communication. These advantages are:

(a) An increased effiCiency due to suppressing the carrier and one side band; ' This makes it possible to have an improved signal-to-noise ratio at the receiver or alternatively a reduction of the power in the transmitter for an equal signal-to-noise ratio in the receiver.

(b) A reduction in the frequency band equal to one half of that required for double sideband operation.

(c) A reduction of the distortion caused by selective fading.

In addition the bandwidth in the receiver needs to be one half of that required in the double sideband case and therefore the noise will be 3 db less, giving a total improvement of 9 db for the Single Sideband method.

SSR-2 Specifications

Frequency Range: 1.5  to  30 MHz .
Circa: 1950.
Sensitivity-  4 microvolts up to 25 MHz
Power input -  110 or 200 to 250 VAC  50 Hz  400 watts.
Dimensions -
Height -  7ft 3 in;
Width - 22.5 in
Depth - 19 in
Weight - 672 pounds. The weight of the cabinet housing the CRD150/20B receivers is extra.

The manual also mentions setting the controls on the CR150/4 receiver but it does not explain the purpose of this receiver.

The SSR-2  system as seen in a three receiver, diversity mode configuration. The CR150/4 (3rd from bottom) and the three CRD150/20B  receivers are mounted in the rightmost rack. For some unknown reason the CRD150/20B rack is not shown in the equipment manual. (Photo courtesy  Le Musée Québecois de la Radio)

Functional elements within the SSR2 rack,. (Drawing courtesy Marconi Wireless)

The manuals that were used to develop this web document have been donated to the Marconi Archive at the University of Oxford.

1) Operating and Service Manual for the SSR-2 receiver  circa 1963.
2) Inter-rack Wiring for CRD150/SSR2/HSR1 circa 1950

Contact information :

Senior Archivist,
Bodleian Library, Weston Library,
Broad Street,
Oxford, OX1 3BG
ENGLAND

E-mail: customerservice@bodleianshop.co.uk
 

 

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Contributors and Credits:

1)  Le Musée Québecois de la Radio - Jacques Hamel, VE2DJQ
2) SSR-2 Operating and Service manual

May 6/17