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Providing a Good RF Ground
This active vertical antenna works well with just a single copper ground rod used as the mounting
rod.
You can test ground quality by listening to a steady local signal. Attach 15 feet of wire laid in a
straight line away from the coaxial feedline. If you observe a change in signal or noise level, you
need to improve the ground. A second rod spaced a few feet away from, and connected to the first
one may correct the problem. If a good ground cannot be established, use a
DXE-RFCC-1
Feedline
Current Choke that will further decouple the feedline from the antenna and reduce common mode
current and associated noise from the feedline.
If locate your ground mounted antenna where ground rods cannot be used effectively, you must use
a radial system or metal ground screen. A suitable radial system consists of four to twelve equally
spaced radials, with each radial being at least 15 feet long, but not longer than 20 feet.
Only if the antenna is located over rock, on a roof, or otherwise installed where conductive soil
conditions do not exist, you must use a ground screen. Welded-wire galvanized screens are okay for
this receive antenna only and are not recommended for transmit antennas. Screen radius must at least
equal the element height and be placed around the antenna as symmetrically as possible, but should
not exceed a radius of 20 feet. The active receive vertical radial system should never be connected to
any metal structure to assure low noise operation.
Do not use elevated radials or grossly asymmetrical radial configurations. The ground system is an
integral part of this receiving system, and if it is asymmetrical or exhibits pronounced resonances,
the antenna system may not function properly.
Connections
For single antenna installations, the
DXE-FVI-1
- Feedline
Voltage Injector is installed near the operating position. When
using the Active Receive Antenna, the
FVI-1
powers the
AVA-2
active antenna through its
ANT+
feedline connection.
See
Figure 8
.
If possible, bury the feed line for some distance from the
antenna. This helps to decouple the feedline from unwanted
noise. A
DXE-RFCC-1
Receive Feedline Choke will also
ensure feedline decoupling.
Connect a suitable 75 Ω feedline to the type F connector
OUTPUT
. Leave a small loop in the feedline to relieve stress
on the
AVA-2
connection and securely attach the feedline to
the mast below the mounting plate.
Figure 8 - Connections to the ARAV3 system
using the FVI-1
