[Elecraft] bias for Yamaha CM-500

[David Christ]

I'm trying to understand the bias requirements for the CM-500 
specifically and electret/condenser (which is it) mikes in general.

Yamaha's adaptor uses 3V  (2 AAA batteries) in series with a 2.2K 
resistor and a 1 microfarad DC blocking capacitor.   I would rather 
not depend on batteries.  My reading of the KSB2 manual says to use 
10K fed from 5V while I have heard that it should be 10K for this 
unit. I am not sure what my K3 is supplies.  I would also like to use 
the mike with a Kenwood TS-940.  That rig has 8V available at the 
mike connector.  So if I build an adaptor to use with that rig what 
is the proper value resistor to use?  Or should I build a quickie 3V 
regulator fed from the 8V and then use a 2.2K resistor?  I presume I 
would need some value of DC blocking capacitor for the Kenwood.

How does one determine the proper voltages and resistance values?  Is 
it to get a specific voltage, current or what?  How close do you have 
to be or is it non-critical?  What difference does it make?  Where 
can one find information?

Thanks all from an old timer who is still trying to get up to date 
from the dynamic and crystal mikes of the 60s and 70s.

David K0LUM