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Tuning
An antenna analyzer is the best way to adjust the resonant frequency of an antenna. Measurements
should be made at the antenna using a short (5 or 6 ft) piece of 50 Ohm coax between the antenna
and the analyzer. If you are too close to the antenna your presence can affect the tuning, if you are
too far, the coax length may act as a radial and resonate. Taking readings close to the antenna also
eliminates the possibility of a long or marginal feedline influencing the tuning or causing erratic
readings. You should tune the antenna for resonance (X=0) rather than for low SWR, although they
are often close or at the same point. Normally, the SWR goes down somewhat and the bandwidth
increases once the feedline is reconnected and you measure the SWR at the operating position.
Tuning the 17M kit
The 17M kit should be added to the antenna and tuned first. Start with the dimensions shown in
Figure 5
. Because this kit has sufficient bandwidth to allow operation across the entire 17 meter
band with a SWR of 1.5:1 or less, adjust the kit to resonate at the middle of the band, or around 18.1
MHz. Adjustment to the resonant frequency is done by slightly loosening the wing nut holding the
Hot Rodz and adjusting the length of the Hot Rodz. Make both Hot Rodz longer to go lower in
frequency, make them shorter to go higher in frequency, Both Hot Rodz should be adjusted equally
and should not need to be adjusted more than a couple of inches. Make adjustments in small steps.
1/2 in. of adjustment should change the resonant frequency by about 75 kHz.
Figure 5 - Hot Rodz Initial Position
Tuning the Vertical
The 17m add-on kit electrically couples to the rest of the vertical and does have some influence on
the tuning of adjacent bands. We recommend restoring the factory-set tubing dimensions of your
BTV prior to making any adjustments. These dimensions are listed in the BTV series installation
manual that came with your antenna. They are also available for download on our website,
www.dxengineering.com, in the Hustler Antenna section.
In some installations, particularly those with very good soil conditions or a very good radial system,
the traps themselves may have been changed from factory dimensions during the initial installation
of the vertical to resonate the vertical in each band. In those cases where the traps have already been
adjusted, leave them as-is for now. If you have doubts about the factory-set trap dimensions, use
Figure 6
to check them.
Check the vertical for resonance on each band and note each resonant frequency. This will help
determine what adjustments are needed. After installation and tuning of the 17m kit, the BTV will
