Rothermel D-104

The Rothermel D.104 is mentioned in Wireless World magazine between 1935 and 1953. It was made in Britain under license from the Brush Crystal Company. It looks very similar to the Astatic D-104 that shares its name. Our example is mounted on a nice ivoroid handle for commentary or talkback use. The sound quality is impressive for a crystal microphone.

From an advertisement in Wireless World, 1953.

"This 'quality' microphone D.104 has been considerably improved sinceit was first introduced and is ideally suited to all uses whichrequire a sensitive high impedance instrument. It is available inthree forms:

Complete hand microphone with white handle and 6 ft. of high quality shielded cable £6.0.0

Head only with three -pin plug and socket stand connector with side cable outlet - less cable £5.10.0

Head only with screw eyes for suspension ring mounting, with 6 ft. of high quality shielded cable £5.5.0

A 1944 BBC Research Department report describes how a modified version of the D.104 microphone, mounted on a spring-clip attachment, was adopted for use with a portable disc recording system for front-line recordings during the Second World War. The modified microphone can be seen in Figure 7.

The D.104 can be seen advertised in various publication in the 1940s for example:

• H. WHITAKER, a radio shop in Burnley, advertise the D.104 for the price of £5 on page 2 of a 1949 copy of The Shortwave Magazine
• London Central Radio Stores advertise a desktop version of the D.104 in a December 1942 copy of Wireless World