Dipole vs EH Antenna,
Comparative Antenna Testing using WSPR and Two Radios
Model: "WB5WPA Mark II Vert"
Two radios transmitting simultaneously, one exciting a 'reference'
antenna and another a test antenna using two different freqs to
differentiate the results at the spotting stations.
Ref Ant - A dipole with center at about 30', dipole is horizontal
Test Ant - A "WB5WPA Mark II Vert" EH Antenna, center line at 25
feet, EH antenna oriented vertically.
Notes:
(1) The EH Antenna is fed via a coupling loop (Link coupled) near the
EH "Tuning coil" and
is not directly connected as normally
depicted on
most websites.
(2) For WSPR reporting, the low-frequency radio was on the EH antenna,
the high-freq
radio was on the dipole antenna.
The WB5WPA EH Antenna "Mark II Vert" mounted on 18 ft mast.
Antenna centerline = 25 ft.
Cylinders are 30.5" long each, 2" ID DWV cellular core PVC pipe
Operatonal and Technical parameters
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
5-24-2013
PVC Pipe: 2" I.D. "DWV" Cellular-core PVC
Cylinders: 30.5" tall cylinders
Input Coil: 2T Below Tuning coil, position for lowest/best SWR
Tuning Coil: 19-Turns, adjust the windings around to tune for 40m WSPR
freq
SWR Freq BW
---- ------ -------
3.0 7006
2.6 7011
2.0 7019
1.5 7026
1.1 7037
1.1 7049
1.5 7059
2.0 7066 47 kHz
2.6 7072
3.0 7076 70 kHz
Q = 115
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Tuning coil (red wire) and 2-turn input coupling loop (underneath black
PVC tape). Coax feed can be
seen coming up to input coupling loop.
Close up of Tuning coil (red wire) and 2-turn input coupling loop
(underneath black PVC tape)
Ref. dipole feedpint at about 30'
The K9AN station is 1086 km at 42 deg AZ from transmitting station
WB5WPA
The W4DJV station is 1336 km at 77 deg AZ from transmitting
station WB5WPA
The WB2EEE station is 2190 km at 59 deg AZ from transmitting station
WB5WPA
The WB2EEE station is 2190 km at 59 deg AZ from transmitting station
WB5WPA
The VE6PDQ station is 2632 km at 334 deg AZ from transmitting station
WB5WPA
The K7TSW station is 2639 km at 309 deg AZ from transmitting
station WB5WPA
The F1VMV station is 8318 km at 47 deg AZ from transmitting
station WB5WPA
KL7OA at 2094 km and 310 deg AZ from transmitting station
WB2EEE at 2190 km and 59 deg AZ from transmitting station
VE6PDQ at 2632 km and 334 deg AZ from transmitting station
DK6UG at 8225 km and 41 deg AZ from transmitting
station