1940 Air Ministry AM Tester Microphone Type 1 10A/8243 Made By Ferranti

This strange looking device is a WW2 1940 Air Ministry AM Tester Microphone Type 1 10A/8243 Made By Ferranti.

A very nice RAF test set related to all the ~WT voice sets. The inbuilt Ferranti voltmeter (scale: 0-10 volts) has the RAF stores reference number 10/8250 with a resolution of 1000 ohm/volt. It was designed to test the sensitivity of carbon microphones and worked in conjunction with a noise generator (10A/ 10154) which is not included.

In pretty good condition, there is damage on the left hand side of the top of the jointed mahogany case, which also has various scuffs and blemishes.

Approximate Size (WHD): 17 x 13.2 x 12.5 cm

Sold as a collectible for display only, a nice piece of ephemera for the militaria collector!