What power you need for 1296MHz-EME-QSO? Tested by Peter Cerveny, EA6ADW (DF5JJ) with real echo tests (5.5m-dish, power range 1W to 1000W) in 1993-1995
Many echo tests with calibrated AGC-voltage (S-Meter) gave following results. All power values are effective at feed! Power range of tests were 1W up to 1000W, antenna 5.5m-dish, 0.30dB-LNA, 250Hz-bandwith.
Gain Dish ERP Ptx --- for 3dB-echo in apogee dBd D (m) (kW) (W) nf=0.3dB, (250Hz-BW)
examples: 5.5m-dish: own echo (3dB) with 30W = 75Werp 5.5m-dish: QSO with 2m-dish, Gain 34dB - 25dB = 9dB , consequently Ptx=30W+9dB=240W for both stations 2.0m-dish: own echos with 1800W!
For QSO´s of yagi-stations with circular-stations you have to add 3dB power for same signal strenght. EA6ADW is able to run linear and also circular mode. In further echo tests below of 0 dB S/N EA6ADW got following results: measured down to 10 Watt, PWR measured definition of quality report 30W 3.0 dB S+N/N = 0dB S/N good readable for random QSOs "O" 20W 2.2 dB S+N/N = -2dB S/N good readable for sked QSOs "M" 15W 1.8 dB S+N/N = -3dB S/N readable for sked "M" 10W 1.3 dB S+N/N = -5dB S/N TMO readable, callsign difficult "T-M" 5W -8dB S/N detectable "T" 3W -10dB S/N temporarily detectable "T"
max.1000W 16 dB S+N/N(250Hz) good for SSB without headphone
Minimal 15-30 kW ERP (real! at feed) are good to work in sked with EA6ADW. I also can switch to linear polarisation ( LR = linear rotatable) , which allowed QSO's with optimal quadro-yagi-groups with elevation-drive. Smallest worked station was 3m-dish, 70W (40kW erp) with 5dB S+N/N, also a 2x72el.yagi, 1200W with 6dB S+N/N, smallest reception was 2m-dish with 100W (but bad RX-performance of partner, QSO NC). My RX-ODX are Cassiopeia 1.0 dB, Cycnus 1.0 dB, Saggitarius 1.5 dB, Moon 0.7 dB