Hello Ash,
Your results are normal for a typical Beverage. Receiving performance
is not significantly degraded by imperfect matching of the coaxial feedline
to the Beverage feed point or by non-optimum termination resistance.
You could optimize your matching transformer and termination resistor
but the improvement in receiving performance will be very minor.
On the other hand, Beverage antenna r eceiving performance can be
significantly degraded by:
- nearby antennas, power lines and other long conductors, and
- common mode signals coupled into the feedline
You could optimize your matching transformer to reduce the VSWR to
closer to 1:1 on the frequencies you care about most, but you won't
notice any improvement in receiving performance.
You could optimize your Beverage termination by:
- adding extra ground rods and/or short radials to improve ground resistance
stability at the connection to termination resistor.
- adjusting the termination resistance to minimize the VSWR excursion
as you sweep from 1.5 to about 10 MHz
73
Frank
W3LPL
----- Original Message -----
From: "Ashraf Chaabane" <ash.kf5eyy@gmail.com>
To: topband@contesting.com
Sent: Wednesday, July 4, 2018 2:13:27 PM
Subject: Topband: Beverage Antenna Tuning
Hi All
I measured the SWR in my beverage antenna; the SWR fluctuates between 1.5
and 3 in a range of 1.8 to 7 MHz. (See:
https://drive.google.com/drive/folders/0B9AtNpPfAOUMRDNsaXROMG1VUTg?usp=sharing
)
I know SWR should not vary too much. However, some people are suggesting
adjusting the termination resistor. Others suggest checking the transformer
number of windings for a good match. What shall I do?
73 Ash 3V8SS/KF5EYY
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