I was curious what the estimated EIRP would be to be able to still receive a data signal through the satellite and I experimented a bit with the WSJT-X and JTDX-software.
My setup: KX3 on 50 MHz (100mW) ==> 0 to 100 dB step attenuator ==> BU500 up-converter ==> filter ==> SG-Labs PA ==> 14m H-100 cable (approx. -7dB) ==> 5 turns helix ==> 1.8m offset dish (CAS 180).
According to my measurements the entire setup is pretty linear, so that I can adjust the power accurately by using the 0 to 100 dB step attenuator between the KX3 and the BU500.
I adjusted the power in a way that my reference power gives a signal that is at the same level as the lower CW beacon. According to some information that was distributed earlier, this corresponds to an EIRP of about 950 Watt (= 300mW into 3m dish in Bochum).
I used a couple of modes but finally settled on JT65 to do my tests.
Result: I can safely decode signals that are 35 dB below the maximum EIRP of the beacon signal, meaning, that an EIRP of only 300mW is sufficient to decode data signals. The table below shows some of the results. The fourth line was received with only 30 dB attenuation, equivalent to 950mW, the others with 35 dB attenuation = 300mW EIRP.
Holger 'Geri', DK8KW
1101 -20 1.0 888 # TEST DE DK8KW
1103 -21 1.0 888 # TEST DE DK8KW
1119 -22 1.1 890 # TEST DE DK8KW
1123 -15 1.1 877 # TEST DE DK8KW
1125 -21 1.1 878 # TEST DE DK8KW
1127 -21 1.0 884 # TEST DE DK8KW