[Elecraft] CM-500

[Augie "Gus" Hansen]

On 11/7/2020 3:42 PM, Bill Frantz wrote:
> ...
> The packaging said (in part), "Dynamic Microphone for Active 
> Musicians". And specs: Operating range: 100-16000 Hz, Sensitivity 
> -56dB 3dB (-36 dB 3dB V/Pa). Pattern: Uni-directional (cardiod).
>
> I plugged it into my K3 and it worked as a direct replacement for the 
> old one. When I turned microphone bias off in the menu it stopped 
> working. By turning bias back on it started working again. (BTW, the 
> Elecraft radios may be the only gear I own that doesn't automatically 
> provide bias power.)

The fact that bias is needed confirms that the "key element" is an 
electret. Ignore the packaging statement about dynamic, which has been 
wrong for a couple of decades. The original CM500 did have a dynamic 
element, but a change was made for reasons not in evidence. Someone 
forgot to tell the marketers and packaging folks.

Gus Hansen
KB0YH