WSPR “Whisper” in Amateur Radio with 10 mW!

WSPR “Whisper” in Amateur Radio with 10 mW!

WSPR or “Whisper” stands for Weak Signal Propagation Reporter software for weak signal communication by radio amateurs, again initially written by Joe Taylor, K1JT, like WSJT. It is now open source developed by a small team. It is meant for low power test transmission on medium frequency and high frequency bands. Frequency shift keying is used to send short messages which are compressed into just 50 bits of data! The message includes callsign, Maidenhead grid locator and transmission power.

A WSPR signal with 5 W has been compared to 2 kW with SSB! If a WSPR station is spotted with 5 W with a signal to noise ratio of -29 dB, then, that station must use at least 2 kW to make a QSO. A WSPR station with a power of 10 mW can be spotted only if the propagation is very good. In that situation it will correspond to a CW signal of 200 mW power. WSPR station of 10 mW has been received at 1100 km on 7 MHz.

Source of information

1. https://a29.veron.nl/hams/pa1b/wspr-with-10-milliwatt/
2. https://en.m.wikipedia.org/wiki/WSPR_(amateur_radio_software)

Courtesy: Adersh VU3WEW