If you are running Airmail with one of the SCS PTC-II multimode digital controllers then you are about a minute from being on PSK31. Using the PTC-II and a basic terminal program will be "bare-bones" but will work well enough to see if you like the mode.
The following assumes that you have a working Winlink/Airmail setup using a SCS PTC-II mdc :
- Bring up Tools..Dumb Terminal . . . from the Airmail main screen
- Turn on the PTC-II then Enter to autobaud if necessary
- Type RESET
- Type PSKT
- Tune your radio to a PSK sub-band (try 7070 USB or 7073 LSB) and set the radio tune rate to smallest step possible. 1 Hz is great, 10 will work, >10 won't.
- To receive, tune radio to a PSK31 signal slowly to center the 3 or 4 green lights and when the outer LEDs flash red, you are on. (If you don't have 1 Hz tuning, use Ctl L and K to tweak the frequency DSP decoder by 1 hz to center the green LEDs.)
- Use Ctl-Y to transmit then Ctl-Y again to go back to receive.
- This will get you on the air. Do a bit of listening and then try a QSO. Have fun.
HyperTerm (comes with Windows) is better than Dumb Terminal (comes with Airmail).
There are programs that support the PTC-II in modes such as PSK31. I tried Alpha and Simple, but wasn't impressed with either. I like PA0NC's NcWinPtc better.
To specify a net frequency for PSK31, state the center frequency. Which sideband you use (USB or LSB) doesn't make any difference; e.g. 7070.000 USB with a 1,120 Hz trace is better stated as 7071.120 center frequency.
If you have to remove the PTC to radio connection to eliminate distortion when talking on SSB you have RF getting into the mdc and you need to fix it.
If not already done, set the power out to a nice low level (10-25 watts) . ( Return to the cmd: prompt and use FSKA- My 706 likes FSKA 125 for 10 watts out.). Setting the PSK31 power this way has the advantage of not requiring a reset when you return to voice.
See the PSK31 chapter in the SCS book for the rest of the commands you could use. Ctl-N is useful to turn off frequency tracking in a "Net" environment. Be careful with Ctl-B because it can switch you out of the BPSK mode.
You can change the center frequency set point of the PTC using TONES 2. (Center freq = (MARK+SPACE)/2 . I have mine set for 600 hz so I can use the narrow IF filter in my IC-706.)
Most PSK31 users use a software-soundcard implementation. To do this, you will need one of the programs (Digipan, Mixw, etc) and a hardware computer:rig interface (Rascal, Tigertronics, etc). These are not needed to test the waters with the PTC-II- your Winlink setup will work.
Here are some other modes that you can try with the same PTC-II setup you use for Winlink:
- Baudot RTTY
- Linked Amtor
- Amtor FEC
- Pactor FEC
- Non- Winlink Linked Pactor
- Sitor FEC broadcast receive (NAVTEX in raw mode)
de w4avo 2/07/06