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ground plate (such as metal roofing exists). A counterpoise can consist of radial
wires or a mesh made of materials such as chicken wire. If radial wires are used the
counterpoise should consist of at least 8 to 10 radial wires, each radial being at
least 5 metres in length. When radials or mesh are used at ground level it is
recommended that they be buried a few centimetres below the surface.
Electrical Checkout
After mechanical installation is complete select the highest frequency to be used on
the transceiver. A directional watt-meter such as a bird model 43 should be
inserted in the coaxial transmission line between the transceiver and the tuner. The
tune mode on the transceiver is then energised (refer to the transceiver user
manual). Upon application of RF energy, the tuner should start to tune, indicated
by the 'clattering' of the tuner relays. After a few seconds the relay noise will cease,
the transceiver should indicate a successful tune and the watt-meter reflected
power should indicate a low value consistent with a VSWR of better than 2:1. Now
select the lowest desired frequency on the transceiver and repeat the above
procedure. The result should be the same, except that the tune cycle may take
somewhat longer. If the above procedure does not give the results as indicated
check that the antenna length and connections are correct and re-check all ground
(earth) connections.
Note:- When received, the Barrett 911 automatic antenna tuner memory system will
usually not have any pre-stored tuning information appropriate to your installation.
To allow the 911 to 'learn' it’s tuning information simply proceed from one channel
to the next allowing the normal tune cycle to take place. Each successful tune is
'memorised' so that when that channel is re-selected the tuner will almost
instantaneously retune to that frequency.
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