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BARRETT 4050 HF SDR TRANSCEIVER - OPERATING AND INSTALLATION MANUAL
Ground (Earth) System
The ground (earth) system is a key part of the overall antenna system and con-
sequently the system operation. An inadequate ground system is the primary
cause of poor performance and tuning problems. There is little point in install-
ing the antenna unless a good ground system can be provided. In areas of
good ground conductivity (i.e. ground always damp), an effective ground can
be made through a grounding rod. This should be approximately three metres
in length and should be installed as close to the tuner as possible. Several rods
bonded together will improve the ground contact. In some cases metal water
pipes may be used as a ground providing:
•
The water pipe is close to the tuner and the water pipe enters the ground
close to the tuner.
•
There are no joints or couplings in the pipe that will increase the resist-
ance path to ground.
•
The water pipe enters soil with good conductivity.
•
A low resistance joint is made with the water pipe.
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-
tory ground for the Barrett 911 tuner. This will almost certainly be the case in
well drained sandy soils or on rock. In these cases, a counterpoise must be used
as a ground system. This will also be the case in rooftop installations where no
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The number of radials required for an effective counterpoise depends on the
soil quality, dampness and other factors which affect the conductivity of the
soil. The more radials used, the better will be the performance of the antenna
/ ATU combination especially at lower frequencies. This manual suggests a
minimum of 20 radials, but optimum performance at low frequencies is not
guaranteed.
The radials of the counterpoise need only be of much thinner cable i.e.
5.48mm
2
(#1 #2 SWG) preferably copper wire. RG58 Coaxial cable may be
used. At the base of the antenna, the radials all couple together at a common
well bonded antenna ground point. The radials should be buried into the
ground to a minimum of 200 mm depth.
Note: To accomplish reliable ATU tunes at frequencies below 5 MHz, it is not
uncommon, with poor conductive soil conditions, to require up to 120 radials each
of up to 70 m length, requiring thousands of metres of cable and a lot of trenching.
This is impractical and is the reason we do NOT recommend Whip / ATU antenna
for land based systems.
Содержание 4050 HF SDR
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