[Elecraft] K3 and YAMAHA CM-500

[Joe Subich, W4TV]

Connect a 5.6K Ohm resistor between pin 6 and the ring of the CM-500
and a 1 uF capacitor between the tip of the CM-500 and pin 1 or
simply *disconnect* pin 6 and use bias for the K3 front mic jack.
Tip and ring are connected together in the CM-500.

There is a 10 uF capacitor from pin 6 to ground (in the DSP power
supply).  That effectively shunts *any* audio to ground <G>.  You
must use the 5K6 Ohm resistor to prevent this loss of mic audio.

73,

    ... Joe, W4TV


On 2014-08-31 3:45 AM, ayoshida wrote:
> If CM-500 is connected to rear panel mic jack it works fine, however
> if it is connected to front panel mic jack via conversion connector
> I have a very low mic lebel with max mic level setting.
> If CM-500 is connected to KX3 it works fine.
>
> CM-500 mic plug to 8p plug connection in conversion connector is like
> this.....
> tip to pin-1
> ring to pin 6 (K3 provides 8V regardless Bias ON/OFF)
> sleeve to pin 7
>
> I have another electret condenser hand mic. If this mic is connected to
> K3 front panel mic jack it works fine.
>
> If CM-500 is connected to K2 (where 5V is provided to pin 6 of mic jack)
> using same
> conversion connector it works fine.
>
> Any suggestions please.
>