914 series manual tap whip antenna
Installation
Do
not use PL-259 UHF connectors.
- Barrett P/N BC91401 to BC91424
914 series manual tapped whip antennas are mounted on vehicles using a heavy duty base
and spring (Barrett P/N BCA91400). The whip should be mounted on the vehicle in
positions such as those illustrated in the diagrams below. A bracket, fabricated to withstand
the forces and vibration that can be expected during off-road driving, should be used to
mount the antenna base and spring to the vehicle. When locating the mounting position for
the antenna, the ring located above the label at the bottom of the whip should be level with
the surrounding ground plane, eg. the bonnet of the vehicle or the roof of the vehicle.
Ensure that the mounting bolt on the base and spring is electrically bonded to the chassis of
the vehicle via a very low resistance path, ie. clean all joints to bare metal and use braid
earth straps if any non-metal joints are encountered. Use only good quality coaxial cable
and water proof UHF connectors (such as those supplied by Barrett Communications).
When running the coaxial cable from the antenna to the transceiver avoid sharp corners and
heat such as that generated by the manifold of the engine. After installing the antenna
check the antenna VSWR on each channel. Generally if the antenna has been mounted in
the positions as illustrated, the VSWR will be less than 1.6-1 and no adjustment is
necessary. If the VSWR is not lower than 2:1 the antenna to ground capacitance in that
installation is probably outside of the design range of the factory set tuning. Consideration
may be given to retuning the whip if the VSWR is so high as to cause the transmitter ALC
system to begin to reduce power (to protect the transmitter).
BARRETT 950 HF TRANSCEIVER
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