PSK-31

I have been using PSK-31 for a while now and I use this mode of communication on HF more often than voice (phone). PSK31's effeciency and narrow bandwidth make it suitable for global communications in poor conditions even using QRP. I designed and built my own interface (see link below) using the following parts:1 x 4N25 opto Isolator (other similar models like the 4N29 or 4N35 would also for fine)1 x LED3 x 100 ohm resistors1 x 220 k-ohm resistor2 x 25 k-ohm pots (log type)1 x 8 ohm to 1 k-ohm matching transformer1 x 1 k-ohm to 1 k-ohm matching transformer (3k to 3k would also be fine)1 x DB9 serial port connector3 x 3.5mm plugs (2 for PC soundcard and one for transceiver ext speaker).Plug to suit your transceivers Mic In socketYou will also need shielded wire for the cable runs from the unit to the soundcard of the PC and from the unit to the transceiver. I have also attached a photo showing the completed project.The software I use is called WinPSK which is free.  Download it from http://www.moetronix.com/ae4jy/winpsk.htmCommon frequencies used are 7035.150 & 14070.150I would love to make some PSK QSO's with LDS hams so let me know when you are ready and we will set up a sked!Let me know if you need any more info!Regards ... Marty