Paul and Peter used WSJT-X 2.2.0-rc1, a beta-release candidate for version 2.2 of the program WSJT-X. Both stations have moderate 4-yagi setups on 432. Conditions today were not particularly good: 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. Nevertheless, as you’ll see in screen shots posted here, copy was solid in both directions:
Why might you want to use FT8 instead of “Old Reliable JT65” for EME QSOs? FT8 is about 4 dB less sensitive than JT65, but with 15-second T/R sequences it’s four times faster and it doesn’t use Deep Search.
When I was active in EME contests on 144 MHz, I was always frustrated that even with reasonably strong (for EME) signals, one’s maximum JT65 QSO rate is about 12 per hour. With FT8 you can do 40 per hour, as long as workable stations are available.
What about FT8 EME on 1296 MHz? It might sometimes work, but Doppler spread will probably make standard FT8 a problem. But if there were sufficient interest, we could make an “FT8B” or “FT8C” with wider tone spacing.
Please try FT8 for EME on any of the bands 144, 432, and 1296 MHz, and let us know your results.
73, Joe, K1JT
The popular WSJT-X software for FT8 can be downloaded from
Moon-Net Email Reflector
Today we take a look at the Xiegu XPA125B QRP Amplifier and Auto Tuner hooked up to the Icom IC-705. This amp will work with a variety of QRP rigs inc... Read more
“I’m taking a 10,000 FT look at three types of ham radio programing software. There’s so much to unpack here that a quick overview i... Read more
“The TIDRADIO bluetooth programmer application is one of the worst aplications I have had to deal with in ham radio. Its odd and makes no sense... Read more
Brand new from YAesu, dropping in October of 2021, is a new dual band Ham Radio, the FTM-6000r. This was announced today, so I wanted to get some rese... Read more
FTM-6000E – 50W transmitting power – Reception range from 108 to 999.995 MHz – New “E2O-III” user interface – Remo... Read more
The Chameleon CHA-MPAS 2.0 just might be the best portable Ham Radio antenna that you can get today, due to its versatile configurations and compact s... Read more
Common Mode Current can really mess with RFI and cause interference in the shack. In addition, you could also be receiving unwanted interference on th... Read more
Today I go through all of the steps and pieces for building the BuddiHex Hexbeam antenna from Buddpole. This might be the best portable ham radio ante... Read more
An important first step in ham radio is figuring out how you want to power your radio station. Reagrdless if it being at home or in the field, you nee... Read more