User manual THULE 573

[. . . ] It will match an amazing range of antennas and impedances, far greater than some other tuners you may have considered. Also, it consumes very little power making it suitable for battery-powered operations. While resembling earlier LDG tuners in overall layout and function, the AT-100Pro represents a quantum leap in features and performance. Enhanced tuning algorithms provide much faster, precise and consistent tuning. [. . . ] 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. Medium Press > . 5 Sec for Auto Tune Bypass mode (Short press) To place your AT-100Pro in bypass mode, press the Tune button less than a half-second. 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. You can if you wish press Func-Tune to save the bypass setting, erasing the memory for that frequency. Power and SWR Indication During a tuning cycle the Power and SWR LED meter indicate forward power and the present SWR, respectively. If you are using a transmitter or transceiver with SWR rollback protection, you will see the forward power vary up and down quite a bit during a tuning cycle. During transmit, both forward power and SWR are displayed if this option is selected in the startup options. When no LEDs are lit on the SWR meter when RF is present, it means that the SWR is less than 1. 1. When the LED segment labeled 1. 1 is lit, it means that the SWR is between 1. 1 and 1. 3. Read each LED segment to mean "equal to or greater than the marked SWR, but less than the next higher marked SWR". 13 Off Mode When any tuning cycle ends, the tuner automatically enters a "deep sleep" state in which it draws just a few milliamps; it is effectively off. The tuner will automatically "wake up" the next time you start a tuning cycle, when RF is present, a button is pressed or when an automatic tuning cycle is required, if this option is selected. The only requirements are that the tuner remain dry, and that you provide a fused source of DC power in accordance with the specifications. The AT-100Pro does not include an internal fuse; you must provide one in the DC line. To install the unit under the dash, you can "homebrew" a bracket. You can also use Velcro tape, although the adhesive tends to soften in hot weather. In the trunk, Velcro works well to secure the unit to the trunk floor. Simply run coax from your transceiver to the tuner, run a fused DC line to the tuner and connect your mobile antenna. Simply set the tuner to Automatic mode, and you're ready to go; the tuner will adjust the match as needed whenever you transmit on a new band or frequency. You can observe the progress of the match on your rig's SWR meter, or on the power output meter (not while driving; keep your eyes on the road!). Most of the time this will happen very quickly, as the AT-100Pro tunes from memory in less than a second. Xcvr Tuner 2A DC When to use Auto mode Auto mode is most useful when you are often changing frequencies and bands (a contest, for instance). With memory operation, Auto mode will retune almost instantly whenever you transmit on a new frequency. On the other hand, if your antenna SWR is relatively flat across the band of frequencies you're using, retuning might not be necessary, and semi-automatic mode would be preferable. 16 When to use Peak mode Any averaging wattmeter will read correctly only when excited by a steady, unmodulated carrier. [. . . ] If the swr is below 2. 0 when you press the tune button to start a tuning cycle, the tuner will first try a memory tune routine to see if it can achieve a low swr without a complete re-tune. A word about tuning etiquette Be sure to use a vacant frequency to tune. However, do your best to avoid interfering with other hams as you tune. Your AT-100Pro's very short tuning cycle, as little as a fraction of a second, minimizes the impact of your tuning transmissions. [. . . ]