WSJT, MAP65, WSPR, and WSJT-X are open-source programs designed for weak-signal digital communication by amateur radio.  Normal usage requires a standard SSB transceiver and a personal computer with sound-card.

WSPR (pronounced “whisper”) stands for “Weak Signal Propagation Reporter.” This program is designed for sending and receiving low-power transmissions to test propagation paths on the MF and HF and VHF/UHF bands.  Users with internet access can watch results in real time at WSPRnet.

So, what do you need to make this work, a 144Mhz SSB radio, an antenna, a computer connected to that radio and the internet.

The most basic of wspr stations is a receive only station, if you also want to transmit, you need to ensure your radio is generally accurate on frequency and stable in its output, some radios (Icom 706’s as an example) wander when they get hot, lots of info available on how to make them more stable.

An antenna, most of the WSPR vhf people are using horizontal antennas, but that isn’t essential, you can have a very successful WSPR station with ANY antenna.. even my little vertical in the backyard gets 600km contacts regularly from this pathetic little antenna 😀 with WSPR, because it will work at/below the noise floor, you can decode what you can’t (often) hear.

Some form of connection from your radio to your computer. My radio an icom ic9100 has a USB Soundcard and CAT control out the back, however, using the WSPR software direct to the radio/usb had never been successful, mostly because the wspr software struggles with the radio CAT control, it worked fine for RX only. But wouldn’t TX. Some use Ham Radio deluxe to overcome this, I’ve tried it and wasn’t super impressed.

My local ham club recently (before the aus$ plummeted) had a group purchase of the signalink USB sound card. This device has been wonderful, it connects to my icoms (and my yaesu fm box) with a 6pin Din and USB soundcard, on my mac (or a windoze netbook) it works a treat. Its enabled me to easily and quickly use many digital modes and track those Ham Balloons

And thats it, once the computer software can hear the radio audio, adjust the levels and listen to see what you can hear. One important factor for Transmitting, is to make sure you adjust you ALC so you don’t have any over driving, Search the web for more info!.

My simple little omni vertical in the backyard and wspr works a treat, below is a 2 week list of stations worked, with 600km contacts not uncommon. A number of people are using the information to help understand propagation and performance and using this mode can help confirm other observations (weather maps and the like).

Give it a go, you will be amazed!