[Elecraft] Need local help

[Joe Subich, W4TV]

The cards I listed yesterday have both mic and line level inputs
(separate jacks) one or the other will be a reasonable match for
the headphone output.

As far as driving the mic input of the KX3 with line (speaker) output,
simply put a 10:1 (20 dB) attenuator in the cable to the mic input.
Typically one would connect a 1 uF cap to the tip of the speaker jack,
a 10K resistor from the cap to another 1 uF cap to the mic input of
the KX3 and a 1K resistor from the junction of the 10K resistor/output
1uF cap to the shield/return (from sleeve of the speaker jack to mic
return of the K3).  Note: the 1uF caps are simply there to block DC
on the sound card output (may not be necessary) and block the bias on
the KX3 mic line (if the KX3 is configured for use with an electret
mic).

If the drive is still excessive, change the 1K resistor to 470 Ohms
(22:1 or -26 dB).

73,

    ... Joe, W4TV


On 2015-06-10 12:02 PM, Mark Tannert wrote:
> It would seem that all these line level input/output sound cards would have
> some difficulty working with the KX3, which uses mic level input and
> headphone level output.
>
> Kindly correct me if I'm wrong.
>
> Cheers, Mark/WN8U
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to lists at subich.com
>