LDG AT-897Plus Operation Manual Download

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AT-897PLUS OPERATIONS MANUAL

MANUAL REV B

PAGE 1

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

[email protected]

www.ldgelectronics.com

Summary of Contents for AT-897Plus

Page 1: ...ONS MANUAL MANUAL REV B PAGE 1 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 2: ...he FT 897 Radio 9 Cable Installation 11 Finishing Up Installation 11 Operation 12 Power up 12 Basic Tuning Operation 12 Toggle Bypass Mode 13 Initiate a Memory Tune Cycle 14 Force a Full Tune Cycle 15 Status LED 16 Application Information 16 Mobile Operation 16 MARS CAP Coverage 17 Operation with a PC CAT 17 Theory of Operation 17 The LDG AT 897Plus 19 A Word About Tuning Etiquette 21 Care and Mai...

Page 3: ...r level The AT 897Plus is powered by the transceiver s CAT interface itself so there is no additional power cable required to use the AT 897Plus Latching relays are used so the AT 897Plus consumes no power when not tuning The AT 897Plus improves upon the previous AT 897 automatic antenna tuner in that the memory has been expanded to 2 000 frequency memories The transmit frequency is actually read ...

Page 4: ...ook up Designed specifically for the Yaesu FT 897 FT 897D HF transceivers Can be mounted directly to the side of the FT 897 Pass thru CAT port allows AT 897Plus to control the FT 897 over the CAT bus while still allowing a host PC to also control the radio Pass thru CAT port waits for idle CAT activity before controlling the transceiver 1 8 to 54 0 MHz coverage Frequency for memory storage is read...

Page 5: ...ower Attempting to tune a greater than 3 0 1 load on six meters at full power can damage your AT 897 tuner Power levels in excess of 50 watts should be used on 6 meters only if the SWR of the load was lower than 3 0 1 prior to tuning If you are unable to check or are unsure of the SWR of the load prior to tuning be sure to reduce power to 50 watts or less when operating on six meters IMPORTANT SAF...

Page 6: ...n be placed in bypass mode by pressing the Tune button momentarily The AT 897Plus is powered directly from the CAT port on the radio no separate power supply is needed The AT 897Plus automatically powers up at the start of a tuning cycle and goes into an ultra low power sleep mode when tuning is complete The latching relays hold the tuned configuration indefinitely even when DC power is completely...

Page 7: ...nd 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: ... those hams who would like to control their FT 897 via computer This is a pass thru port to the 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 t...

Page 9: ... 897 transceiver by mounting it to the left side of the transceiver Mounting is not required but if it is desired to mount the tuner to the left side of the radio no modifications to the radio are needed Mounting the tuner to the radio requires a small Phillips cross point screwdriver preferably one with a magnetized tip If a magnetized tip screwdriver is not available tweezers may be need to aid ...

Page 10: ...les inside the AT 897Plus these should line up with the holes in the side of the radio Using a magnetized screwdriver or tweezers place the four included mounting screws into the mounting holes and carefully tighten them Do not over tighten 5 Place the cover back on the tuner and replace the screws that hold it on 6 Screw the four plastic feet onto the left side of the tuner That s it Next follow ...

Page 11: ...Rotate the SEL knob until menu 019 CAT RATE is visible Rotate the main tuning knob until 4800bps is showing Next rotate the SEL knob one click clockwise to select menu 020 CAT LIN TUNER Rotate the main tuning knob until CAT is showing Now press and hold FUNC again to return to normal operation Finishing Up Installation Connect a 50 ohm coax feedline to the jack marked ANT on the rear of the AT 897...

Page 12: ...ceptable match was found the inductance and capacitance settings are saved in a memory associated with the selected frequency so that they may be recalled quickly in the future via a memory tuning cycle In this manner the AT 897Plus learns the longer you use it the more closely it adapts itself to the bands and frequencies used Most users will probably use memory tuning most of the time it takes a...

Page 13: ...h 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 The Status LED will flash once to indicate that the tuner is no longer bypassed This function may be useful if you wish to compare antenna performance with and without the benefit of the tuner s matching network ...

Page 14: ... 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 When tuning is complete the transceiver will return to the operating mode and power level previously set Be aware that the AT 897Plus tunes in AM mode The microphone input is live during tuning so anything you say will be heard while tuning ...

Page 15: ... a better match than the match already stored in memory for this frequency To force a full tuning cycle press and hold the Tune button on the front panel of the AT 897Plus until the Status LED lights up and keep holding until the Status LED goes out again Release the Tune button once the Status LED goes out A full tuning cycle will begin When tuning is complete the transceiver will be restored to ...

Page 16: ...APPLICATION INFORMATION Mobile Operation The AT 897Plus is perfectly suited to mobile operation It can be installed under the dashboard along with the transceiver or mounted remotely 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 c...

Page 17: ...ly hook up a PC and use the rig control software as normal Press the TUNE button on the AT 897Plus when tuning is desired 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 ...

Page 18: ...ther than 50 ohms When the impedance of the antenna is different from that of the transmitter and transmission line a mismatch is said to exist In this case some of the RF energy from the transmitter is reflected from the antenna back down the transmission line and into the transmitter If this reflected energy is strong enough it can damage the transmitter s output circuits The ratio of transmitte...

Page 19: ...n additional relay switches between high and low impedance ranges A built in SWR sensor provides feedback the microprocessor searches the capacitor and inductor banks seeking the lowest possible SWR The tuner is a Switched L network consisting of series inductors and parallel capacitors LDG chose the L network for its minimum number of parts and its ability to tune unbalanced loads such as coax fe...

Page 20: ... a difficult tune 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 repea...

Page 21: ...se decision TWO YEAR TRANSFERRABLE WARRANTY Your product is warranted against manufacturer defects in parts and labor for two full years from the date of purchase 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 There is no need to complete a warranty car...

Page 22: ... in process until it ships back to you Please be assured that our staff makes every effort to complete repairs ahead of our published wait time Your patience is appreciated Repairs can take six to eight weeks but are usually faster The most recent information on returning products for service is found at the LDG Customer Support Center Send your carefully packaged unit with the Repair Form to LDG ...

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