"wb0gaz" wrote in message
oups.com...
This is probably not that complicated (I hope?!?) but I need a PC
program that would just tell a PC soundcard to generate a standard
CTCSS tone (example 107.2 Hz) sinewave that could be fed into an older
FM amateur transceiver. I don't want to find/buy/build a CTCSS module
for it, and will have a PC handy. I imagine a WAV file could be
created, but if there is some kind of software (perhaps a "function
generator" program) that would be ideal, particularly if you could just
give it the frequency in Hz or something like that, and get a steady
sine wave out of the sound card.
Very tks,
73 Dave WB0GAZ
Dave -
You may be missing the point of CTCSS. It is NOT like "Touch Tone" sounds
that can be insert through the microphone input and pass through the audio
chain.
Never insert the CTCSS Output (from any CTCSS encoder board or source) to
the microphone input of a radio.
The radio's microphone audio stages will distort and attenuate the CTCSS
signal (defeating the whole purpose)
The most common place to connect the CTCSS Output to is just prior to the
modulation stage in the transmitter.
Typical connections would be: to the center of the deviation pot, to the
varactor diode in the modulator circuit, or to the manufacturer's suggested
connection point. This connection point for the CTCSS can vary from radio to
radio. A schematic of the radio is very useful.
Since the CTCSS Output from your sound card may be low impedance, you may
have to install a series resistor to reduce the loading effects from the
sound card (CTCSS) Output --- depending on the interface impedance.
This is evident in the case of connecting to the center of a 10K deviation
pot. In this case, a 10K series resistor will compensate for the impedance
difference.
In addition, a slight adjustment of the voice deviation may be required to
compensate for the CTCSS Output circuit loading.
The CTCSS encoders from ComSpec or PIEXX are easy to install and less than
$50 .
gb