DX Engineering 4-BTV, Руководство по установке

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Hustler
®
Trap Calibration - Resonance Adjustment Procedure
Tune all Hustler
®
BTVs starting with the 10 meter trap , because any adjustment done there
affects the rest of the antenna, regardless of the number of bands it has.
1. Slightly loosen the band clamp at the bottom of the trap sleeve , NOT the clamp on the
larger tube below .
2. Loosen the trap cover.
3. Adjust the trap sleeve position on the
trap bottom tube. Typical adjustment
is to move the trap sleeve downward
on the trap lower tube about 1/4 to 1/2
inch reducing the A2 dimension
below the 10 meter trap for a shift of
+500 kHz.
4. Firmly tighten the band clamp.
5. Reposition the trap cover.
6. Raise the antenna, re-test to find the
new frequency and SWR dip.
7. Readjust (repeat steps 1-6) to move
the SWR dip to the desired frequency.
After you adjust one trap, check all bands
before repeating steps 1 though 7 for the
other traps in order (15M then 20M then 30M depending on BTV model).
It is not necessary and counter-productive to readjust the spacing (A2, B2, C2 or D2) to the original
chart dimension after a trap sleeve adjustment. In some cases, you may need to increase these
spaces between the trap sleeves and the antenna sections to allow enough spacing to complete
recalibration.
Note : Like other antenna adjustments, trap adjustments are not permanent and can be restored
easily. You marked the position of the trap sleeve on the trap lower tube before you started, so
returning to the starting point will be simple.
Do not worry if you cannot tune the antenna to the lowest possible SWR of 1.0:1 at your frequency
of choice. A minimum SWR of 1.4:1 to 1.6:1 is acceptable for HF operations, representing a minor
RF power reflection of only 3 to 5%.
Your new high efficiency antenna system is now properly installed and tuned and will reward you
with years of service.
In some cases if you are still low in the resonant frequency, you may have to adjust A1, B1, C1, D1,
E1 in small increments depending on which band(s) is/are effected. If you do make these
adjustments, trap calibration may also require some further adjustments.