Table of Contents
Related Manuals for LDG AT-897Plus
Summary of Contents for LDG AT-897Plus
- Page 1 AT-897PLUS OPERATIONS MANUAL MANUAL REV B AT-897Plus Automatic Tuner for Yaesu FT-897(D) LDG Electronics 1445 Parran Road St. Leonard MD 20685-2903 USA Phone: 410-586-2177 Fax: 410-586-8475 ldg@ldgelectronics.com www.ldgelectronics.com PAGE 1...
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Page 2: Table Of Contents
Jumpstart, or “Real hams don’t read manuals!” Specifications An Important Word About Power Levels An Important Word About Tuning on the Six Meter Band Important Safety Warning Getting to know your AT-897Plus Front Panel Rear Panel Installation Compatible Transcei vers... -
Page 3: Introduction
INTRODUCTION LDG pioneered the automatic, wide-range switched-L tuner in 1995. From its laboratories in St. Leonard, Maryland, LDG continues to define the state of the art in this field with innovative automatic tuners and related products for every amateur need. -
Page 4: Specifications
7. Select the desired operating frequency and mode. 8. Push and hold the TUNE button on the front of the AT-897Plus for one second (until the Tuning LED comes on), then release. The transceiver automatically switches to AM mode, and keys up with a minimal amount of power, and the AT-897Plus begins a tuning cycle. -
Page 5: An Important Word About Power Levels
AN IMPORTANT WORD ABOUT TUNING ON THE SIX METER BAND The AT-897Plus is designed to tune loads on 6m that start out at 3.0:1 SWR or lower. Attempting to tune a greater than 3.0:1 load on six meters at full power can damage your AT-897 tuner. -
Page 6: Getting To Know Your At-897Plus
If no memorized settings are available, the tuner runs a full tuning cycle, storing the parameters for memory recall on subsequent tuning cycles on that frequency. In this manner, the AT-897Plus “learns” as it is used, adapting to the bands and frequencies as it goes. PAGE 6... -
Page 7: Front Panel
Front Panel On the front panel there is one pushbutton and one LED indicator light. • Tune Button: Initiates either a memory tune or a full tune, and also toggles the tuner between “active” and “bypass” modes. • Status LED: Lights to give feedback on button presses, lights during tuning; gives tune status at the end of a tuning cycle. -
Page 8: Rear Panel
CAT Out port, and is switched under software control by the AT- 897Plus’s microprocessor. The firmware of the AT-897Plus has been written such that this will seem transparent to the user -- if using CAT to control your FT-897, just plug the PC’s CAT cable into this port instead of the CAT jack on the back of the transceiver. -
Page 9: Installation
The AT-897Plus tuner is designed for indoor operation only; it is not water resistant. If you use it outdoors (Field Day, for example), you must protect it from the rain. The AT-897Plus is designed for use with coax- fed antennas. If use with longwires or ladder-line-fed antennas is desired, an external balun is required. - Page 10 4.Position the AT-897Plus on the left side of the FT-897, over the screw holes that used to hold on the radio’s plastic feet. The end of the tuner with the SO-239 jacks goes toward the rear of the radio. There are four recessed mounting holes inside the AT-897Plus, these should line up with the holes in the side of the radio.
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Page 11: Cable Installation
Finishing Up Installation Connect a 50-ohm coax feedline to the jack marked ANT on the rear of the AT-897Plus, and connect this to the antenna system. If it is desired to operate the FT-897 via computer control, connect the Yaesu CT-62 CAT interface cable to the AT-897Plus port labeled “CAT In”. -
Page 12: Operation
Although the FT-897 is designed to transmit and receive on all HF bands plus 6 meters, 2 meters and 70 centimeters, the AT-897Plus is designed only to work on HF and 6 meters. In addition, the FT-897 transceiver transmits UHF and VHF on a different antenna jack than the jack used for HF and 6 meters. -
Page 13: Toggle Bypass Mode
Toggle Bypass Mode: To toggle between bypassed and active mode, press the front panel Tune button on the AT- 897Plus momentarily. The Status LED will flash three times to indicate that the tuner is in bypass mode. Press the front panel Tune button momentarily again to recall the previous tuner settings. -
Page 14: Initiate A Memory Tune Cycle
To initiate a memory tuning cycle, press and hold the Tune button on the front of the AT- 897Plus until the Status LED lights up. A memory tuning cycle will begin. The AT-897Plus will force the transceiver into AM mode, change the power level to one that is appropriate for tuning, and key the radio. -
Page 15: Force A Full Tune Cycle
In this case, forcing a full tune will cause the AT-897Plus to seek a better match than the match already stored in memory for this frequency. -
Page 16: Status Led
The only requirement is that the tuner remains dry. The supplied radio interface cable is 14 inches long. If it is desired that the AT-897Plus is positioned farther from the transceiver than this cable length allows, a custom cable will need to be constructed. -
Page 17: Mars/Cap Coverage
The AT-897Plus monitors the Computer port for activity before beginning any tuning cycle. Only when the CAT line is idle for a period of time will the AT-897Plus take over control of the CAT line in order to perform a tuning cycle. When the tuning cycle is complete, control of the CAT interface is returned to the PC. - Page 18 The output circuit of a transmitter consists of inductors and capacitors, usually in a series/parallel configuration called a “pi network”. The transmission line can be thought of as a long string of capacitors and inductors in series/parallel, and the antenna is a kind of resonant circuit.
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Page 19: The Ldg At-897Plus
This allows the AT-897Plus to handle loads that are either greater than or less than 50 ohms. All relays are sized to carry 125 watts continuously. - Page 20 provide a DC voltage proportional to RF power. These two voltages are read by the ADCs in the microprocessor, and are used to compute SWR in real time. The relays are powered by the 12VDC input provided by CAT interface cable. The relays are a latching type, and so they consume no current when not actively switching.
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Page 21: A Word About Tuning Etiquette
This two-year warranty is also transferable. When you sell or give away your LDG product give the new owner a copy of the original sales receipt and the two- year warranty goes with the new owner. -
Page 22: Returning Your Product For Service
Returning a product to LDG is easy. We do not require a return merchandise authorization, and there is no need to contact LDG to return your product. Simply ship your tuner to the address below, and include a note describing the issue in as much detail as possible, and include your name and contact information.