FT8 Used for Moonbounce (EME) Contact
/Two amateur radio operators, Paul W2HRO and Peter PA2V used WSJT-X 2.2.0-rc1, a beta-release candidate for version 2.2 of the program WSJT-X to make a successful earth-moon-earth contact. Both stations have moderate 4-yagi setups on 432. Conditions were not perfect, degradation around 3 dB, and the Sun only 20 degrees from the Moon.
For terrestrial use, the FT8 decoder searches over the range -2.5 to +2.4s for clock offset DT between transmitting and receiving stations.
When "Decode after EME delay" is checked on the WSJT-X "Settings" screen, the accessible DT range becomes -0.5 to +4.4 s. Just right for EME.
FT8 uses 8-GFSK modulation with tones separated by 6.25 Hz. At the time of this QSO the expected Doppler spread on the W2HRO - PA2V EME path was 8 Hz, which causes some additional loss of sensitivity.
