Check for WSPR Drift using G3ZJO Multimode MEPT on 10.140073 MHz

The Drift value given in WSPR can be useful yet needs some understanding to interpret. Until recently I personally paid only passing regard to the figure.

An interesting thing is that the only station that does not see drifting banana like signals on the waterfall is the person producing them.

Following recent discussions on Knights QRSS. I think we can come to a few conclusions. The decoded value is the result of drift from the TX station and the Rx station. If the two stations drift in opposite directions the figure will cancel and severe drift could be masked.

To establish your own drift on RX you need to use another WSPR signal that is known not to drift.
My Mutimode MEPT full fills this role. Being continually in the TX mode the Drft over 2 minutes can be assumed to be Zero.

A good check would be:-

Tune the VFO to 10.1386MHz or any other dial frequency that allows coverage of the MEPT.
Observe the Drift figure over several RX only 10 minute periods.
Observe again immediately after a TX period.
Any further indicated Drift value will be due to frequency variation in your Transceiver due to TX cycle heating.

The G3ZJO Multimode MEPT now transmits WSPR (MEPT_JT) every 10 minutes. In addition it identifies with a 'G' 'G' in QRSS3 Morse - 'G' 'G' in RTZ Morse (Dashes above, Dots below, the Zero line) - 'G3ZJO' in S/MT 5 unit Hellschreiber - 'G3ZJO' in an experimental Morse mode STEP. This sequence takes 8 minutes prior to the WSPR (MEPT_JT) data.