To fill a requirement for communication over distances that the Wireless Set 19 was not designed to fulfil, a separate RF Amplifier was designed, that could be installed on top of the WS19.

The Amplifier has it's own internal dynamotor to generate the HT for the 4 x 807 valves in the Mk1 and 2 x 807 valves in the Mk2 and above.

To control the Amplifier a special dogbone is used, that engages the transmit relay in the Amplifier when the operator presses transmit.

The Amplifier's case differs from the 19 set case, as a fan outlet is on the rear, which includes an air filter.

Note: The dynamotor's were produced with a very brittle casting, more brittle than normal, if the Amplifiers have been shipped and dropped, they can become cracked. The outcome is the dynamotor breaking up when powered on, causing much damage.