[Elecraft] CM-500

[Joe Subich, W4TV]

> (BTW, the Elecraft radios may be the only gear I own that doesn't
> automatically provide bias power.)
Kenwood, Yaesu and Ten-Tec transceivers do not provide bias for an
electret mic at all. To use an electret mic with those transceivers
one needs to install a "power adder" (5K6 Ohms resistor between pin
pin 5 (Kenwood) or pin 2 (Yaesu/Ten-Tec) and the tip of the CM500
and a 1 uF capacitor in series between tip of the CM500 and pin 1
(Kenwood) or pin 8 (Yaesu/Ten-Tec)) unless one is using the Yamaha
"battery box."

73,

    ... Joe, W4TV


On 2020-11-07 5:42 PM, Bill Frantz wrote:
> Thanks for everyone's comments on the CM-500 headset. To bring my 
> question about reattaching the mic boom full circle, I decided to throw 
> money at the problem which seems to have made it gone away. :-)
> 
> I ordered a new CM-500 from B&H Camera and Video ($60, no tax, free 
> shipping). It arrived a day early in good shape. It included the 
> headset, two 3.5mm to 1/4 inch adapters, one mono the other stereo, and 
> a box that holds two AA cells which I haven't used. There were no 
> instructions for use, but it did include the usual warning about using 
> them with AC powered equipment in a hot tub, and hearing damage from 
> playing them too loud.
> 
> 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.)
> 
> I managed to make a QSO with it, so it's working well enough to pass my 
> call to the other end. I hope people on the SSB nets tomorrow will give 
> an audio quality check.
> 
> 73 Bill AE6JV
> 

elecr