[Boatanchors] Microphones

[Raymond Cote]

I have a couple mics that I got fr mil surplus and all I can find on them is be 100 to 10k BW, and it says imp of 150 ohms. Other discussions on these lists state that some radios are hi z and some are low z. What is or what are the common accepted  input req for mics?  I should know but my bench has been stored away for  a few years and I am fuzzy on this. 
Thanks

Raymond Cote
1466 Townline Rd
Steward Ill 60553
808-341-8213
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