These are some of the reasons I like WSPR mode:
- About 100 stations (or more) can co-habit in a 200Hz wide WSPR sub-band on each band, time and frequency sharing. In reality, usually far fewer stations on worldwide per band.
- Low power is all you need 1mW to 5W is quite fine. I tend to use 1-2W, but have been spotted at DX distances with a few mW. Some even use uW power levels!
- If there is an opening everyone has a fair chance (anyone can be spotted at great ranges)
- Simple antennas work. No need for beams on HF.
- Can monitor activity (your own and that of others) in the lounge by visiting website www.WSPRnet.org on any PC or tablet.
- Speaking not needed (saves my stroke damaged voice).
- Highly sensitive (12-14dB better than 12wpm CW?).
- Can do other things whilst WSPRing.
- Automatic – requires no manual intervention once running.
- Ideal for accurate comparative measurements (e.g antennas, rigs).
- Ideal for propagation experiments.
- About QRSS10 equivalent.
- Works from VLF to UHF (watch stability on higher bands).
- A QRP man’s dream mode.
- For 2-way QSOs use JT9-1 (about 2dB worse than WSPR).
- Needs accurate timing (usually sync’d to internet time).
- Need good frequency accuracy.
- Usually needs a PC (not always e.g Hans Summers Ultimate 3 and similar kits).
- Needs careful interfacing to rig to avoid loops and 50, 100Hz sidebands.
Download WSPR software at http://physics.princeton.edu/pulsar/K1JT/wspr.html .