WSPR

The latest thing I've been trying out is WSPR, a new weak signal digital mode from Joe Taylor, K1JT. This mode uses a narrow-bandwidth, low power (typically 5 watts or less) signal that transmits information at a slow speed designed to be decodeable even at very low signal levels. This mode is not used for two-way communications. Rather, the WSPR software runs your transmitter in beacon mode for a precise block of time (2 minutes), and then listens for other signals the rest of the time. You can control how much time (in terms of percentages) you spend transmitting vs. listening. A typical setup would be to transmit 20% of the time (2 minutes out of every 10). The software randomizes the transmit time, so your transmit schedule won't end up matching other stations' exactly (i.e., if you transmit 20% of the time, you're guaranteed to transmit for 2 minutes out of every 10 minute block, but where in that block it happens is random.). Running WSPR, you can see other stations operating in this mode as well as acting as a beacon yourself.

In addition to the WSPR software, there's also the WSPRnet Weak Signal Propagation Reporter Network. The WSPR software can be configured to automatically upload logs of all the stations you received through WSPR in real time, where they are added to a database and shown on a real-time map. This enables you to quickly see what propagation paths are open on a given band. You can also see on this site where your signal is being received.

It's an interesting mode. I've been trying it out and have been very impressed with how the software can decode stations whose signals are so weak that I can't even hear them. And I've been impressed with the reports that came back of other stations hearing my signal, which has been only 5 watts into a mobile whip antenna.

Details of activity to follow in a later post.