[CQ-Contest] Need advice

[Richard Ferch]

Dick,

I agree with what Kirk wrote, with one addition.

Someone else has posted a suggestion about using different tones on the
two radios. The two channels in the stereo sound card don't care whether
you use the same or different tones. As far as the software is concerned,
you can use the same tones in both.

If you like to listen to RTTY signals either to help with fine tuning or
simply so you are aware of which radio the received signals are coming
from without having to look, then you can wire up a cable assembly for
stereo headphones with the input to the left ear from one radio and the
input to the right ear from the other radio. This lets you use the same
tones in both radios and distinguish between them by left vs. right. If
you are using mono headphones, then using different tones in the two
radios might help distinguish between them. Either of these is in lieu of
the more elaborate audio switching an SO2R box can do. If you don't like
to listen to RTTY, you don't need either of these.

73,
Rich VE3KI


Kirk K4RO wrote:

If it's just RTTY SO2R that you are interested in, then you probably don't
need a DX Doubler. Depending on the software you use, you can probably
accomplish what you want with just a couple of serial ports and a simple
interface on each port. AA5AU's RTTY contesting site and the N1MM user
manual should give you a lot of ideas. A serial port can handle PTT and
FSK keying (one port for each radio.) All you need for receive is a stereo
sound card with a line input, and the appropriate cabling to your radios.
You may need a simple resistor pad if your radios don't have a line level
output and you have to use the headphone output instead.