User manual LDG ELECTRONICS AT-1000PRO 1KW

[. . . ] LDG AT-1000Pro 1KW Automatic Memory Antenna Tuner Manual Version 1. 0 LDG Electronics 1445 Parran Road St. Leonard, MD 20685 (410) 586-2177 ldg@ldgelectronics. com www. ldgelectronics. com 1 LDG AT-1000Pro 1KW Automatic Memory Antenna Tuner Table of Contents Introduction IMPORTANT TUNER SAFETY WARNINGS Jumpstart, or "Real hams don't read manuals!" Specifications Operating Instructions Getting to know your AT-1000Pro Installation Setup Version Display: Tune Memory Clear Power-Up On/Off Function Modes Operation Button Functions and LED Indications Normal Operation Memory Operation Fine-tuning the tuner Error Indications A word about "roll-back" circuits LED Error codes Default Setting Radio Interface Theory of Operation Some basic ideas about impedance Transmitters, transmission lines, antennas and impedance The LDG AT-1000Pro The LDG AT-1000Pro Care and Maintenance Technical Support Warranty and Service 3 3 4 4 5 5 7 7 7 8 8 8 9 9 10 10 11 11 11 12 12 12 13 13 13 14 15 17 17 17 2 Introduction Congratulations on selecting the LDG AT-1000Pro tuner. The AT-1000Pro is an important update of LDG's flagship tuner, now providing fully automatic antenna tuning with memories for high power amplifiers. The AT-1000Pro is intended for use with most tube or solid-state amplifiers outputting up to 1, 000 watts SSB. [. . . ] Memory Operation At the end of each successful tuning cycle (SWR <1. 5), the tuning parameters are stored in nonvolatile memory. For each antenna port, there are four banks of 2, 000 memories, allowing you to use an external 4-way antenna switch connected after the antenna jack. Each time a tuning cycle is started, if a previous successful tune was performed on the given frequency, the stored parameters for that frequency are quickly tried. If one of the stored parameters gives an SWR of 1. 5 or less, the tuning cycle ends. If not, a full tuning cycle begins automatically, with the new tuning parameters stored automatically upon successful completion of the cycle. The Tune LED will blink five times, indicating a good tune and a memory save. The memory storage and tuning process is completely automatic, with no impact on your operation of the tuner. The effect is much faster overall tuning once the tuner has "learned" your most common bands and frequencies. You will probably want to use memory tuning most of the time. 10 Fine-tuning the tuner In certain circumstances, the automatic tuning cycle will end with a relative high SWR, perhaps 1. 8 or 2. This is usually due to operation far from the antenna's natural resonant frequency. You can manually adjust the match using the Ind and Cap Up and Down buttons on the front panel. While still transmitting with your exciter after the automatic tuning cycle ends (amplifier still off), press these buttons and observe the effect on SWR on the meter. Since you don't know how the automatic tuning cycle set the inductors and capacitors, you will have to make manual adjustments by trial and error. Press the Cap or Ind Up button three times and observe the change in SWR. If it gets worse, tap the Dn button three times to return to your starting place, then try three taps of the Dn button. Once you've gone through this process a few times, you will get a better feel for matching certain antennas or frequencies. Frankly, you won't use the Cap and Ind buttons or the Hi/Low Z buttons very often; your AT1000Pro is very good at finding a match. These buttons are included only to provide you with maximum flexibility and utility. Error Indications The LEDs may indicate several error and status states: Power too low: your AT-1000Pro requires at least 5 watts to tune. Loss of power during tune: if RF power is removed before a tuning cycle has ended, all LEDs will flash twice. Final SWR over 3: in rare cases, your AT-1000Pro will not be able to achieve an SWR lower than 3. This is most often due to attempting to tune very far from the resonant frequency of your antenna, or load up a lawn chair. [. . . ] The tuning routine uses an algorithm to minimize the number of tuner adjustments. The routine first de-energizes the high/low impedance relay if necessary, and then individually steps through the inductors to find a coarse match. With the best inductor selected, the tuner then steps through the individual capacitors to find the best coarse match. If no match is found, the routine repeats the coarse tuning with the high/low impedance relay energized. [. . . ]