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Old 14th Sep 2018, 2:40 pm   #9
CambridgeWorks
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Join Date: Jun 2010
Location: Spalding, Peterborough, Cambridgeshire, UK.
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Default Re: Telephone style microphone ID req

Pye PMR mics often had a plain aluminium colour insert with impedance of 2400 ohms.
FM had 3 tiny holes, AM more larger holes like in your red/white example.
However, just to confuse, early fm also had several of the larger holes as well. They were sought after for amateur use rather than the 3 hole ones. Maybe someone remembers their part number?
I think AM had "M4BZ2400" printed on the back.
Rob
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