Active Whip Antenna
This antenna was removed from service in July 2011. A DX Engineering AVAR-1P active vertical receive antenna is used in this installation. It mounted about 0.3 m above ground level on a ground rod driven approximately 2 m in native earth. The ground rod is bonded to a nearby ground-laid radial, and the receive amplifier is bonded to the ground rod. The stainless steel vertical whip antenna is 102 in. long. The advertised bandwidth of the active antenna is 100 kHz to 30 MHz and the advertised 3rd-order intercept is given as +30 dBm. The receive amplifier is powered through the coaxial transmission line by a dc feedline injector assembly near the receiving station.
Photographs of Installation
What appears to be a grave site actually is a small cedar
picket
fence surrounding the active antenna installation. The fence is
not large enough or robust enough to keep marauding moose from
trampling the equipment (moose are arguably the dumbest of all
deer), but it does serve to mark the site.
Active antenna receiver assembly. The brass
base of the whip
antenna may be seen to
the left of the receiver. The antenna
connects to the receiver assembly near the top under the
upper wing nut (black lead). The earth ground is connected
under the wing nut on the left (green lead). At the bottom of the
receiver assembly is the coaxial cable connection. The brownish
material around the connector is 3M Skotchkote
used to seal
the connector (the connector also is wrapped with 3M Temflex
2155 rubber self-sealing splicing tape and 88T heavy-duty vinyl tape).
Another view of the receiver assembly (without the fence).
A few
coils of the RG-6 coaxial cable feedline may be seen below the receiver.
The receiver and antenna assembly are mounted on a ground rod and
bonded to it.
A long view of the entire active antenna unit including
the whip antenna
and receive
assembly but not including the "grave site marker". The
102 in. whip antenna is marked with bright green surveyor
flagging to
aid
visibility.
