An Inexpensive WSPR Receiver for 630 Meters

The SoftRock Lite II for 455 kHz IF operation provides an inexpensive but effective way to monitor WSPR activity on 630m. The receiver kit cost $23 USD from This is a software defined receiver that uses a 464 kHz local oscillator. After building the kit, measure the actual local oscillator frequency. In my receiver it was 463.936 kHz. Subtract the actual local oscillator frequency from the WSPR dial frequency of 474.200 kHz. Using a I/Q compatible program such as WSPR 2.12 or Linux WSPR 4.0 open Setup > I/Q Mode. Enable I/Q mode and enter your calculated value in Hz into “Fiq(Hz)” In my case this value is 10264. Alternately, you could use the nominal value of 10200 and make frequency correction adjustments from that point.

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Gene W3PM