[CQ-Contest] CM-500 headset.

Jim Brown k9yc at audiosystemsgroup.com
Wed Nov 21 20:46:11 EST 2018

On 11/21/2018 4:35 PM, DXer wrote:
> Just to clarify, most modern Icoms need an electret element. The SB-40 
> is dynamic, so a blocking capacitor is needed.

A blocking capacitor is super easy to add. Also, the mic jacks on most 
rigs I've owned have V+ to power an electret mic on one pin and mic 
input on another with either a wire jumper or small resistor between the 
two pins. FWIW, the Koss that K6LL likes is the SB45.

It's nearly always useful to study the manual for our radios to see what 
options are provided. Elecraft rigs starting with the K3 have a menu 
setting to turn bias on and off. As rigs have gotten more sophisticated, 
features like this have been added to many by the smarter mfrs.

73, Jim K9YC

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