[Drake] Re: Sound Card to Drake

[Barry L. Ornitz]

Don, K4BEV, asked:
> Is there a way to use a computer sound card with a T-4XC?
> Is a high impedance transformer all that's needed? Or is anything
needed
> between the computer and the transmitter?

There is no need for a step-up impedance matching transformer as the
sound card has a fairly high level output and the microphone input
only expects millivolts.  The sound card output is low impedance which
means it is essentially a stiff voltage source.  You will need an
attenuator to drop the voltage level to something the T-4X expects.
There is no need to match impedances here as maximum audio power
transfer is not needed.

At one time Radio Shack sold an "attenuating dubbing" cord that might
be able to work between the sound card and the rig.  You can also make
an attenuator using fixed resistors or an adjustable one using a 1 to
5 Kohm audio taper potentiometer.

        73,  Barry L. Ornitz     WA4VZQ     ornitz@tricon.net