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Data from the WSPR web site relating to
monitoring from VK6YSF Northam Western Australia.
WSPR
Frequency: Dial 1.8366MHz USB (occupied bandwidth 1.8380 -
1.8382 MHz)
Grid location: OF88II
Local Time = +8:00 hours (0:00 =
8:00AM)
TX Only
SSN (Sun Spot Number): 25 - 39
Equipment: TS-930 at
5W, Radio computer
interface
Antenna#1: Multi-band
dipole with T-Match tuner and 4-1
Current Balun
Antenna#2: 'T"
Antenna configuration with T-Match tuner
This exercise was to
compare the Multi-band
dipole antenna with the same antenna configured as a 'T"
Antenna used
for operations on the 160m amateur band.
The main HF antenna is an All Band Doublet feed with ladder line and
matched with a T-Match antenna tuner including a 1:4 current balun
giving access to all HF band including the 160m band. With a view to
get better performance particularly on lower frequency bands this
antenna was reconfigured as a type of Marconi ‘T’ Antenna by
simple bonding the ladder line in the shack and connecting directly
to the T-Match antenna tuner.
This antenna requires a counterpoise to work well and this will achieved
at least initially by using the galvanized building roof to serve
this purpose.
The below results
clearly indicate that the Marconi ‘T’ antenna configuration has significant performance improvement
when compared to the Doublet antenna for long distance operation, however for local contact
there was no noticeable performance difference between the two
antennas. There was an approximately 10dB improvement with the Marconi ‘T’ antenna when in contact with VK2KRR as compared with Doublet
antenna.
WSPR data has been graphed using
Excel. Horizontal axis = UTC Time, Vertical axis = dB below the
noise floor.
Antenna#1: Multi-band
dipole with T-Match tuner and 4-1
Current Balun
Antenna#2: 'T"
Antenna configuration with T-Match tuner
VK6YSF WSPR Signal received
by:VK2KRR The Rock, NSW Australia
Distance: 2832km
Grid location: QF34mr
dBm: 37
WSPR data has been graphed using
Excel. Horizontal axis = UTC Time, Vertical axis = dB below the
noise floor.
Antenna#1: Multi-band
dipole with T-Match tuner and 4-1
Current Balun
Antenna#2: 'T"
Antenna configuration with T-Match tuner
VK6YSF WSPR Signal received
by:VK6PK
Distance: 37km
Grid location: OF88ee
dBm: 37
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