On Monday, 21 Feb 2005 16:00:56 -500, "Asimov"
wrote:

"Insert 2 audio signals into the MIC Connector
1.9kHz at 3mV
1.3kHz at 3mV

A piano even does semi-tones... 10 at a time, 11 if you use your nose!

With some kind of PC, search for a program that can generate multiple
tones (e.g. some electronic instrument imitations) or use two programs
capable of generating a sine wave and mix them together with the PC's
audio mixer and run the combined signal to the sound card output and
to an audio amplifier.

The hardest part is getting some kind of calibrated output level.

One way of doing this with very simple test gear would be to put a low
impedance 40 dB attenuator between the audio amplifier and the mic
input.

Using a single 50 or 60 Hz sine tone from the sound card and a DVM at
the amplifier output, adjust the amplifier output voltage to 300
mVrms, the microphone input will now be 3 mVrms. It is important to
use 50/60 Hz, since a typical DVM frequency response would be quite
bad at 1.3 or 1.9 kHz.

Now turn the 1.3 and 1.9 kHz tones on and make the transmitter
adjustments.

Paul OH3LWR