Summary of AT-200Pro
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At-200pro automatic antenna tuner manual version 1.0 ldg electronics 1445 parran road, po box 48 st. Leonard md 20685-2903 usa phone: 410-586-2177 fax: 410- 586-8475 ldg@ldgelectronics.Com www.Ldgelectronics.Com.
Page 2: Ldg At-200Pro
2 ldg at-200pro automatic antenna tuner introduction 4 jumpstart, or “real hams don’t read manuals!” 3 specifications 4 an important word about power levels 4 getting to know your at-200pro 5 installation 7 operation 8 basic operation 8 tuning 11 auto and semi-auto modes 12 memory tuning 12 full tun...
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3 introduction congratulations on selecting the ldg at-200pro tuner. The at-200pro provides fully automatic, any mode antenna tuning across the entire hf range plus 6 meters at power levels to 250 watts. It will tune dipoles, verticals, yagis or virtually any coax-fed antenna. It will match an amazi...
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4 specifications • 0 to 250 watts ssb and cw peak power, 200 watts continuous (100 watts on 6m) • easy to read led bargraph display for rf power, swr and status • 16,000 "3-d" memories for instantaneous band changing • two position antenna switch with memories for four antennas on each position • tu...
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5 getting to know your at-200pro your at-200pro is a quality, precision instrument that will give you many years of outstanding service; take a few minutes to get to know it. • your at-200pro can be used with any transceiver or transmitter with coax output operating in the hf range at no more than 2...
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6 on the back panel, there are six connectors: • rf input (marked “ tx ”, standard so-239 socket) • antenna connector 1 (marked " ant 1 ", standard so-239 socket) • antenna connector 2 (marked " ant 2 ", standard so-239 socket) • dc power in (2.5 by 5.5 mm power jack marked " power ", center positiv...
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7 installation your at-200pro tuner is intended for indoor use only; it is not water resistant. If you use it outdoors (field day, for example) you must protect it from rain. The at-200pro is designed for use with coax-fed antennas. If you wish to use it with longwires or antennas fed with a balance...
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8 operation basic operation all functions are controlled through the seven front panel buttons. Each function is invoked when the key is released . Some commands are indicated by the length of time you hold a button before releasing it. There are three lengths of press: short (less than 0.5 seconds)...
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9 menu options your at-200pro offers several options to adapt the tuner to your operations. Many functions are controlled using the func button. Press and release this button to place the tuner in function mode. You will see an "up arrow" display on the led meters, indicating function mode. Function...
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10 peak mode on/off: the led wattmeter will read in average or peak watts. Average mode is most suitable for 100% duty cycle modes like fm or rtty. Peak mode is most suitable for modes in which the amplitude varies, such as ssb or am. The default is average mode. To toggle between these two modes, p...
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11 auto tune threshold: you can set the swr at which an automatic tuning cycle will begin. Press and release the func button. Then press and release the l dn button. The swr meter will show the new setting. Repeat this sequence to cycle through the available values (1.1 - 3.5). The default value is ...
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12 tuning auto and semi-auto modes in auto mode (see section on selection auto or semi mode) the tuner will begin a tuning cycle whenever the swr exceeds the value you set (see section on setting autotune threshold). In semi mode a tuning cycle begins only when you start one by pressing the tune but...
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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...
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14 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. Durin...
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15 operation with an ldg radio interface: operation with an optional ldg radio interface is even simpler. With the interface installed on an alinco, icom or kenwood radio as noted, simply press the tuner or at button on the radio; for yaesu radios, press the tune button on the tuner to begin an auto...
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16 func + key func hold + key hold on power up hold on power-up for all reset peak/avg mtr mode na hi/lo imp sel ant na auto/man tune mode na man store rly settings na 12/125 watts mtr scale na auto thresh. Pres. Thresh. Na func c up l up ant c dn l dn tune power na na version at-200pro key referenc...
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17 application notes mobile operation the at-200pro is perfectly suited to mobile operation. You can install it under the dash along with your transceiver, or remotely in the trunk. The only requirements are that the tuner remain dry, and that you provide a fused source of dc power in accordance wit...
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18 when to use peak mode any averaging wattmeter will read correctly only when excited by a steady, unmodulated carrier. Any modulation will cause the reading to vary. Peak mode measures the peak power as the name indicates, and is much steadier in the presence of modulated highs and lows. You will ...
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19 theory of operation some basic ideas about impedance the theory underlying antennas and transmission lines is fairly complex, and in fact employs a mathematical notation called “complex numbers” that have “real” and “imaginary” parts. It is beyond the scope of this manual to present a tutorial on...
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20 rises to 2, 3 or higher. As a general rule, modern solid state transmitters must operate with an swr of 2 or less. Tube exciters are somewhat more tolerant of high swr. If your 50 ohm antenna is resonant at your operating frequency, it will show an swr close to 1. However, this is usually not the...
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21 the ldg at-200pro in 1995 ldg pioneered a new type of automatic antenna tuner. The ldg design uses banks of fixed capacitors and inductors, switched in and out of the circuit by relays under microprocessor control. A built-in swr sensor provides feedback; the microprocessor searches the capacitor...
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22 second to run. There is also a quick tune mode. 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. This also takes about a half second to run. If it does not ...
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23 minimize future upgrade costs. Upgrades are expected to cost about $10-$20 with chip exchange, and will be announced on our web site when available. Feedback if you have an idea to improve our software or hardware, please send us a description. If we incorporate your idea in the at-200pro, we'll ...