This receiver, also 'known as type 231, is a fixed wavelength  receiver, and is designed to meet certain requirements.

This is a simple circuit single valve receiver fitted with reaction and designed for use on a fixed wavelength. It is self contained as all the batteries needed are in the receiver case.
The receiver is designed to tune to 220 metres (1363 Khz) with an aerial consisting of a single wire of 7/19 silicon bronze 75 feet in length. The internal adjustment allows for variation of about 20 per cent. on either side of  the nominal wavelength. .

The circuit diagram of the receiver is given in fig. 367, and will be seen to consist of a fixed variometer tuned aerial circuit, a grid-condenser rectifier, fitted with reaction, and a telephone
transformer for adapting the output of the set to the low resistance telephones.
 

Courtesy Handbook of Technical Instruction for For Wireless Telegraphists

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Contributors and Credits:

1) Lewis Bodkin  <05bodkin555(at)gmail.com>
2) Handbook of Technical Instruction for For Wireless Telegraphists
 

Sept 14/19