Amateur Radio Station G3YPP

WSPR

Typical 60m WSPR Display

WSPR is the Weak Signal Propagation Reporter Network.  

The network is designed to coordinate experimentation on the propagation of radio waves on a number of frequencies across the whole radio spectrum using very low power.  It involves transmitting very low power signals, and listening for weak signals, on set frequencies and reporting the results to a central database via the Internet.  These are then made available publicly via the website http://wsprnet.org

The signals sent are "digitally encoded" with details of callsign, location and power level transmitted using special software designed for the purpose.  Hence the transmitter and receiver are linked to, and controlled by, a computer.  Also, because the signals are sent at very low power, and the data rate is very slow, the timing of the transmissions is critical to within one second to enable listening stations around the world to synchronise their receivers; it is vital that the computer clock is kept accurate and this is achieved by using Internet Time Servers.   It is usual to leave systems running for many hours or days to understand exactly what is happening to the propagation over time.

Time Servers  Normally, Windows will update it's computer clock weekly or daily depending on it's settings.  However, this may not be accurate enough for WSPR operations which requires the clock to be accurate to +/- 1 second.   I therefore run the Meinberg NTP Server system on each PC on my LAN.  My main server updates regularly from internet time servers and this accurate time is distributed to all PCs on the LAN including the shack computer.   By this means all computers are kept to within 2 milli-seconds of the correct time. 

A map of current activity can be seen at http://wsprnet.org/drupal/wsprnet/map

My own experimentation is carried out on the 60m band - an experimental band which is not available to Radio Amateurs throughout the world.   It is available in the UK to holders of a "Full" Amateur Radio Licence.   Hence, conducting WSPR experiments on 60m is fully conducive with the experimental nature of the band.    To date the results have been extremely interesting and surprising with my 5 watt signals reaching long distances into Europe and the USA.