2m (70cm) (23cm) EME antenna pictures
Array #5
16 x 8el. SP7DCS YAGI (based on WB9UWA 6el. YAGI)
boom 3.8m long, 2.6m H x 2.5m V stacking
Theoretical gain = 25.1 dBi (by YO)
Stacking loss = open wire feed system, about 0.2dB
Preamp - FHX35, about 0.5 dB NF, about 18 dB gain
Coax loss (to shack) = 1/2" coax, 7/8" coax and 1 5/8" coax, about 1.2 dB
Rotor and tracking - SATTRACK, SPID ELEKTRONIK
SP7DCS 8el. YAGI - YO file
Open-wire feed system description (39KB)
2m EME antenna construction details gallery
Plots:
Antenna was optimized for high F/B and low sidelobes to decrease TVI problems and for good VSWR to be able to work also during bad weather (rain, snow etc.)
Pointing at the moon during Italian EME Contest 05
Parked to safe position
Temporary array 2005
4 x 8el. SP7DCS YAGI (based on WB9UWA 6el. YAGI)
boom 3.8m long, 2.6m H x 2.5m V stacking
Theoretical gain = 19.05 dBi (by YO)
Stacking loss = 7/8" coax, about 0.4 dB, from old array
Preamp - FHX35, about 0.5 dB NF, about 18 dB gain
Coax loss (to shack) = 7/8" coax and 1 5/8" coax, about 1 dB
Rotor and tracking - SATTRACK, SPID ELEKTRONIK
In the background H frame of my old destroyed antenna :(
Array #4 - from 2003 to 2004
4 x (21 el. H + 21 el. V) SP7DCS CROSS-YAGI, 13.5m long, 5.5m H x 5.2m V stacking
Theoretical gain for horizontal polarization = 23.9 dBi (by NEC/WIRES 2.0)
Theoretical gain for vertical polarization = 23.1 dBi (by NEC/WIRES 2.0)
Stacking loss for each polarization = 7/8" coax, about 0.4 dB
2 x Preamp , one for each polarization - FHX35, about 0.5 dB NF, about 18 dB gain
H/V polarization switching by coaxial relay
Coax loss (to shack) = 7/8" coax and 1 5/8" coax, about 1 dB
Rotor and tracking - SATTRACK, SPID ELEKTRONIK
Preamps and relays in the box
Before upgrade in August 2004:
Stacking loss for each polarization = H500 coax, about 1.1 dB
H/V polarization switching by coaxial relay
Preamp - FHX35, about 0.5 dB NF, about 18 dB gain
Coax loss (to shack) = 2 dB
My son had to sit down when he saw how big our array was... (hi)
My family is checking the phasing lines... (hi)
Temporary array 2003
2 x (21 el. H + 21 el. V) SP7DCS CROSS-YAGI, 13.5m long, 5.5m H stacking
Theoretical gain for horizontal polarization = 20.9 dBi (by NEC/WIRES 2.0)
Theoretical gain for vertical polarization = 20.1 dBi (by NEC/WIRES 2.0)
Stacking loss for each polarization = H500 coax, about 0.6 dB
H/V polarization switching by coaxial relay
Preamp - FHX35, about 0.5 dB NF, about 18 dB gain
Coax loss (to shack) = 2 dB
Array #3 - from 2000 to 2001
(21 el. H + 21 el. V) SP7DCS CROSS-YAGI, 13.5m long
Theoretical gain for horizontal polarization = 17.9 dBi (by NEC/WIRES 2.0)
Theoretical gain for vertical polarization = 17.1 dBi (by NEC/WIRES 2.0)
H/V polarization switching by coaxial relay
Preamp - FHX35, about 0.5 dB NF, about 18 dB gain
Coax loss (to shack) = 0.7 dB
Array #2 - from 1998 to 2000
4 x (10 el. H + 10 el. V) SP7DCS CROSS-YAGI, 5.3m long, 3.5m H x 3.5m V stacking
Theoretical gain for horizontal polarization = 20.8 dBi (by NEC/WIRES 2.0)
Theoretical gain for vertical polarization = 19.4 dBi (by NEC/WIRES 2.0)
Stacking loss for each polarization = about 0.8 dB
H/V polarization switching by coaxial relay
Preamp - FHX35, about 0.5 dB NF, about 18 dB gain
Coax loss (to shack) = 0.7 dB
Array (hi!) #1 - 1997
10 el. SP7DCS YAGI, 5.3m
Theoretical gain = 14.5 dBi (by NEC/WIRES 2.0)
