Operating Instructions; Getting To Know Your At-1000 - LDG AT-1000 Manual

Operating Instructions

Getting to know your AT-1000

Your AT-1000 is a quality, precision instrument that will give you many years of outstanding service; take
a few minutes to get to know it. On the front panel, there are six pushbutton switches:
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Power: turns your AT-1000 on and off
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Manual capacity and inductance adjustments (if needed)
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Ind Up: increases inductance
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Ind Dn: decreases inductance
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Cap Up: increases capacity
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Cap Dn: decreases capacity
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Tune: begins an automatic tuning cycle
The Power switch does not turn the tuner completely off. It places it in a low-current "sleep" mode that
retains the last tuned setting, providing DC power remains connected. When turning on with power button,
the tuner is automatically restored to the last tuned setting. If DC power is interrupted, the tuner will revert
to bypass mode on power-up. The Cap Dn and Ind Dn buttons are also used in combination to place the
tuner in "bypass" mode, as described later in this section.
In addition to the pushbuttons, there is backlit a cross-needle meter. This meter indicates forward power up
to 1,000 watts, reflected power up to 180 watts and SWR (see Theory of Operation, below). Power readings
are accurate to +/- 5% of full scale across the entire range (this may very well be the most accurate
wattmeter you own!). This meter also indicates various operational states, as described later in this section.
Forward and reflected power are indicted on individual scales. SWR is read at the intersection of the two
needles, on the curved red scales across the center of the meter face. In the picture below, the meter is
indicating an SWR of 2.0.
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