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DU 3000 Antenna Tuner
Tuning
1. Select the band and frequency of desired operation.
2. Set INPUT, OUTPUT and INDUCTOR controls to the suggested settings before
applying transmitter power. Actual settings may vary from one antenna to the
other.
3. Set up your transmitter to a low power output. If your transmitter has a TUNE or
RTTY position, select that position.
4. If you use a linear amplifier, set it to STANDBY.
** Do not use the linear amplifier until the DU 3000 is tuned **
WARNING: Do not exceed 3000 W (Single tone or key down).
5. Set POWER RANGE switch to 300 W.
6. Set the OUTPUT SELECTOR switch to BYPASS, or the position matching your
antenna connection. To tune your antenna, the switch selection must be set to:
COAX 1 TUNED, COAX 2 TUNED, or BAL. LINE+COAX 2. Selecting COAX 1
DIRECT, COAX 2 DIRECT, or BYPASS.
7. Rotate the INPUT and OUTPUT controls for maximum noise or signal as heard on
your receiver.
8. Key your transmitter and adjust the power level for a reading of maximum 50 watts
on the FORWARD scale. Adjust the INPUT and OUTPUT controls for a minimum
REFLECTED reading while maintaining a FORWARD reading of 50 watts using
your transmitter power control.
9. Read the SWR on the red scale at the point where the two needles intersect.
Repeat step 8 until the lowest SWR reading is obtained. The SWR should be 2:1
or lower.
NOTE: This procedure takes patience the first time. The INPUT and OUTPUT
Controls vary the capacitors and provide fine adjustments.
