LDG AT-200Pro Manual - page 13
13
Release the Tune button; an automatic tuning cycle will begin. You will hear the relays in your
AT-200Pro as they switch in and out seeking a match; they make a buzzing noise. The tuning
cycle will end in a few seconds with the SWR LED meter indicating the final match. At the end
of a full tuning cycle, the SWR LEDs will scan inward from both ends to indicate a successful
tune to an SWR of less than 1.1.
2
Unkey your transmitter or transceiver and reset to your desired power if you changed for tuning
−
you’re ready to operate. The new tuning parameters are stored for the present operating
frequency, replacing any parameters that were previously stored for that frequency.
Memory Tuning Cycle (Medium press)
If you are tuning near a frequency at which you have already completed a tuning cycle, you can
reset the tuner very quickly by using a Memory Tuning Cycle. Key your transmitter as described
above, and press and hold the Tune button for .5 to 2.5 seconds, then release. The tuner will
automatically check for a saved tuning setting, and if present will restore that setting in a small
fraction of a second. If no tuned setting is saved near the present frequency, the tuner will begin a
full tuning cycle, saving the result when finished for future operation on that frequency. In this
way, your AT-200Pro “learns”; the longer you use it, the more closely it adapts itself to the bands
and frequencies you use. You will probably use Memory Tuning most of the time; it takes
advantage of any stored tuning settings, but automatically defaults to a Full Tuning cycle if no
stored data is available.
Memory frequency step size varies with band. Steps are very small on the 75 meter band to
accommodate the expected higher Q of most antennas, whereas the step size is somewhat larger
on 10 meters where antenna Q is usually lower.
Bypass mode (Short press)
To place your AT-200Pro in bypass mode, press the Tune button less than a half-second. The
tuner will switch to bypass. All LEDs will flash once to confirm bypass mode. In bypass mode
RF from your transmitter goes directly to the antenna with no matching. A second short press
toggles the tuner back to its last tuned setting; the LEDs show which C and L relays are
energized. Bypass followed by
Func+Tune
will clear the present memory. Bypass mode is not
saved when you power down. On the next power up, the tuner will reset the last tuned settings.
You can if you wish press Func-Tune to save the bypass setting, erasing the memory for that
frequency.
2
LDG's chief engineer, a fan of Snoopy in the Peanuts comic strip, calls this the "Happy Dance".
Medium Press > .5 Sec for Auto Tune