At-7000 automatic antenna tuner for icom ic-7000 manual version 1.0 ldg electronics 1445 parran road st. Leonard md 20685 usa phone: 410-586-2177 fax: 410-586-8475 ldg@ldgelectronics.Com www.Ldgelectronics.Com copyright © ldg electronics 2006. All rights reserved..
2 ldg at-7000 automatic antenna tuner for icom ic-7000 introduction 3 jumpstart, or “real hams don’t read manuals!” 3 specifications 4 an important word about power levels 4 getting to know your at-7000 5 installation 7 operation 8 application notes 9 fixed station operation 9 expert button 9 mobile...
3 introduction congratulations on selecting the ldg at-7000 tuner. The at-7000 provides automatic antenna tuning for your icom ic-7000 (and some other icom radios) across the entire hf range plus 6 meters. It will tune dipoles, verticals, yagis or virtually any coax-fed antenna. It will match an ama...
4 specifications • 0.1 to 125 watts ssb and cw peak power, 100 watts digital • 2,000 memories for instantaneous frequency or band changing • tuning time: 0.5 to 6 seconds full tune, • built in frequency counter for memory operation • frequency coverage: 1.8 to 54.0 mhz. • tunes 4 to 800 ohm loads (1...
5 getting to know your at-7000 your at-7000 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-7000 is designed specifically to work with the icom ic-7000 transceiver. It can also be used with other icom transceivers...
6 on the back panel, there are four connectors: • rf input (marked “ tx ”, standard so-239 socket) • antenna connector (marked " ant ", standard so-239 socket) • interface jack (marked " radio ") for connecting the control cable to the ic-7000 or other compatible transceiver • ground connector (wing...
7 installation your at-7000 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-7000 is designed for use with coax-fed antennas. If you wish to use it with longwires or antennas fed with a balanced tr...
8 operation your at-7000 is controlled entirely through the tuner/call button on the ic-7000 transceiver. Feedback on tuner operation is provided by the tune icon in the upper left of the radio’s display. When you power up the radio, the at-7000 powers up and automatically resets to a bypassed condi...
9 application notes fixed station operation your at-7000 operates well as a base-station tuner. You can position it on top of, or under the radio. Placing it elsewhere on your operating desk is possible, but you would need to “homebrew” a longer control cable; ldg does not provide a longer cable. He...
10 full tune : press the button for more than 2.5 seconds to start a full tuning cycle, even if parameters are stored for that frequency. As you hold the button down, the led will light, then go out; release the button after the led goes out. The led will light during any tuning cycle. When a memory...
11 mobile operation your at-7000 is perfectly suited to mobile operation. You can install it under the dash along with your transceiver, or remotely in the trunk if you are using the ic-7000’s remote head capability. To install the unit under the dash, you can "homebrew" a bracket (ldg does not prov...
12 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...
13 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...
14 the ldg at-7000 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 a...
15 a word about tuning etiquette be sure to use a vacant frequency to tune. With today’s crowded ham bands, this is often difficult. However, do your best to avoid interfering with other hams as you tune. Your at-7000’s very short tuning cycle, often only a fraction of a second, minimizes the impact...
