LDG AT-1000 Manual - page 7
Cap Dn: The Cap Dn button subtracts capacitance; holding the button down auto-repeats the subtract. Both
meters bounce fast at the Low mark when you reach the lower capacitance limit.
Ind Up: The Ind Up button adds inductance; holding the button down auto-repeats the add. Both meters
bounce fast at the Low mark when you reach the upper inductance limit.
Ind Dn: The Ind Dn button subtracts inductance; holding the button down auto-repeats the subtract. Both
meters bounce fast at the Low mark when you reach the lower inductance limit.
Cap Up + Ind Up: Manually stores the current tuning settings. The REVERSE meter will bounce High,
followed by the FORWARD meter High to indicate a successful save. If the FORWARD meter bounces
twice, it indicates that a new set of tuning parameters has been saved. A single FORWARD bounce
indicates that the current tuning settings are the same as the most recently saved settings, and no new
memory usage is needed.
Cap Dn + Ind Dn: Places the tuner in bypass mode; RF is routed directly to the antenna with no matching.
The meter bounces slowly at the Low mark to indicate bypass mode. If the tuner is bypassed in this
manner, pressing the Tune button will
not
restore the most recent setting; the tuner will remain bypassed
until a new tuning cycle, either memory or full, is executed.
Cap Up + Cap Dn: Sets all capacitors to the Antenna side. The FORWARD meter bounces fast at the High
mark. This is typically never used as the tuner will always over ride any setting the user selects on the next
tuning cycle.
Ind Up + Ind Dn: Sets all capacitors to the Transmitter side. The REVERSE meter bounces fast at the High
mark. This is typically never used as the tuner will always over ride any setting the user selects on the next
tuning cycle.
Normal Operation
When you first apply DC power, with or without power-up options, the tuner defaults to its Off state, in
which the tuner is in Bypass mode; RF goes directly to your antenna with no matching. The Power LED
will flash once to indicate successful DC power connection.
To prepare the tuner for use, press the “Power” button on the front panel. The red LED above the button,
and the meter lights come on, indicating that your AT-1000 has powered up and successfully completed a
self-test. The tuner resets to the last tuned setting before the previous power-down.
Set your amplifier to standby, so it will not operate when you transmit; tune with your exciter only. Set
your exciter to transmit 20 watts (without rollback; see below), or up to 100 watts (with rollback) on the
frequency you plan to use. CW is usually the most convenient mode, but you can also use FM or an AM
carrier.
While transmitting 20 – 100 watts, press and release the “Tune” button on the tuner front panel; an
automatic tuning cycle will begin. You will hear the relays in your AT-1000 operate as they switch
inductors and capacitors in and out seeking a match; they make a fairly loud buzzing noise. You can
observe the present reflected power and SWR on the meter during the tuning process—but watch closely; it
happens fast! The tuning cycle will automatically end in a few seconds, with the meter indicating the final
achieved SWR, usually 1.7 or less. Check for an SWR of 2 or less. If the SWR is greater than 2, use the
manual adjustment buttons to adjust the SWR to level less than 2. Unkey your exciter.
The meters may indicate several error and status states:
Power too low: your AT-1000 requires at least 5 watts to tune. If the power is too low, the FORWARD
meter will bounce once to the High mark. In this case, increase power and begin a new tuning cycle.
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