An old ish thread I know... but seemed the best place to put this...
Thought you might be interested to see this Tannoy variation on the Microphone, Respirator No 1 I got recently.
Unsure when these were introduced (I assume WW2) and quite when used... have never seen one before, or photos or documentation about them (but perhaps I've not lifted the right rock yet).
If anyone has any info, would be greatly appreciated.
Microphone, Respirators, Power, No. 1, YA 2816:
Cheers
Tim