WSPR
WSPR shows open paths on the HF bands At our 16 February meeting, James ZL2ET gave us an interesting talk on WSPR (pronounced "whisper") and its applications. Doug ZL2AOV summarised it as: "James ZL2ET discussed the challenges and possibilities involved in low-power, very low-speed propagation testing. WSPR (Weak Signal Propagation Reporter) is a computer-driven way to find out which bands are open, when and between what sites; it correlates this data and provides it on-screen. "Using a presentation prepared by Steve Nichols G0KYA, James took us through the equipment needed: a computer with a sound-card to generate the slow-speed FSK used, a transceiver with accurate and stable frequency control, a source of accurate time (propagation paths are found by comparing accurate time slots of data), and an internet link to upload the data to a central repository for automatic analysis and dissemination. Viewers can see what’s going on by pointing their web browsers at www.wsprnet.org. The files can be analysed by band, time, and even by transmitter source ... allowing insights into amateur radio DX prospects. "Transmitters don’t want to be high-powered (maximum five watts is fine) and milliwatts is possible. A Raspberry Pi model B can be programmed to…