LDG AT-100Pro, Operation Manual

Page 1: ...IONS MANUAL MANUAL REV B PAGE 1 LDG AT 100Pro 100W Automatic Antenna Tuner 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: ...Mode 14 Error Indication 15 Advanced Operation 15 Manual Inductor Capacitor Adjustments 15 High Low Relay Adjustment 16 Manual Memory Store 16 Status Check 16 Application Notes 17 Mobile Operation 17 Conserving Power When Operating on Batteries 18 Internally Generated RF Noise 18 MARS CAP Coverage 18 Theory of Operation 18 Some basic ideas about impedance 18 Transmitters transmission lines antenna...

Page 3: ...table for battery powered operation JUMPSTART OR REAL HAMS DON T READ MANUALS Ok but at least read this one section before operating the AT 100Pro 1 Connect the supplied 50 ohm coax jumper cable from the antenna jack on your transceiver to the TX jack on the back of the AT 100Pro 2 Connect your antenna s 50 ohm coax feedline to the ANT 1 jack on the rear of the AT 100Pro 3 Connect the supplied DC ...

Page 4: ...sions 7 5 x 5 5 x 2 0 Weight 1 5 pounds AN IMPORTANT WORD ABOUT POWER LEVELS The AT 100Pro is rated at 125 watts maximum power input at most Many ham transmitters and transceivers and virtually all amplifiers output well over 125 watts Power levels that significantly exceed specifications will definitely damage or destroy your AT 100Pro If the tuner fails during overload it could also damage your ...

Page 5: ...cle Momentary push places tuner in bypass PWR Meter Bargraph display indicates forward power in 0 12 5 and 0 125 watt ranges SWR Meter Bargraph display indicates SWR during tuning or transmission Each of the pushbuttons has the primary function listed above when pushed Additionally pressing the FUNC button before pressing any other button will activate that button s secondary function labeled bene...

Page 6: ...m antenna coax feedline to this SO 239 connector Ant 2 Connect a second 50 ohm antenna coax feedline to this SO 239 connector Gnd wing nut Connect to the antenna system ground Tx Connect a 50 ohm jumper coax from this jack to the ANT jack on the rear of the transceiver Radio optional Connect the supplied radio interface cable to a supported ICOM or Yaesu radio Power Connect the supplied DC coaxial...

Page 7: ...radios supporting the AH 3 or AH 4 external tuner connect the 4 pin Molex connector of the supplied ICOM interface cable to the radio s Tuner port Then connect the 1 8 stereo plug on the other end of the ICOM interface cable to the jack marked Radio on the rear of the AT 100Pro Connect the coaxial DC power plug of the ICOM interface cable to the 12 VDC Power jack For Yaesu FT 857 and FT 897 use th...

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Page 9: ...ns Press the Func button and release then press the Ant HiLoZ button and release ButtonA ButtonB ButtonC The three buttons are held simultaneously Startup Options The AT 100Pro has three commands that can only be issued when first applying DC power That is to issue these commands first unplug the DC coax power cable then hold down the appropriate button combination while plugging the DC coax power...

Page 10: ...ion mode the AT 100Pro will flash an up arrow on the LED display after the Func button is pressed Function mode times out after a few seconds if no other button is pushed Alternately function mode can be cancelled by pressing the Func button again In either case when Function mode is exited a down arrow is displayed on the LED display Peak Mode On Off The Power display on the LED bargraph can disp...

Page 11: ...ng or fully automatic tuning In semi automatic tuning mode a tuning cycle will not begin unless specifically requested by pressing the Tune button In fully automatic tuning mode a tuning cycle will begin any time there is RF present and the SWR exceeds a pre set level The default setting is fully automatic tuning mode To toggle between semi and fully automatic modes press Func C Dn Auto The LED di...

Page 12: ...n the antenna is selected Transmitting and Receiving During receive operation no LEDs are normally lit on the AT 100Pro During transmit the forward RF power level is displayed on the PWR bargraph and the SWR is displayed on the SWR bargraph If the LED On Off toggle is set to off however then no LEDs light up on transmit to save battery power When reading the SWR bargraph an illuminated LED on the ...

Page 13: ...fixed tuning sequence where the AT 100Pro rapidly tries varying combinations of inductance and capacitance values and then zeroes in on the best match possible When the tuning cycle is complete if an acceptable 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 c...

Page 14: ... radio will automatically reduce power switch to CW mode and begin transmitting while the full tuning cycle is in progress If not key the radio Talk into the mic on SSB or AM close the key on CW until the tuning cycle is complete As with the memory tuning cycle when the tuning cycle is complete the LEDs will scan inward to indicate a successful tune Bypass Mode The AT 100Pro may be placed in bypas...

Page 15: ...e tuning process This is more likely to occur when attempting to tune an antenna far from its resonant frequency The C Up C Dn L Up and L Dn buttons may be used to increment or decrement the amount of capacitance or inductance respectively A momentary press of any of these buttons increments or decrements the value by one unit and displays the resulting value on the bargraph meter Capacitance valu...

Page 16: ...ily then Tune Store momentarily to store the current relay settings in the memory associated with the frequency last transmitted upon Status Check The status of most user settings can be checked by pushing and holding the Func button while pressing the relevant button for that setting For example to check to see what the current SWR threshold value is without changing the value press and hold the ...

Page 17: ... the supplied cables can be extended in two ways The original cable can be cut and jumper wires soldered between all the connections or new connectors can be purchased and a pair of homebrew extender cables made with the new connectors With the AT 100Pro mounted for example in the trunk simply set the AT 100Pro for fully automatic mode It will automatically tune any time the SWR exceeds the prepro...

Page 18: ...RATION 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 this subject4 but a little background will help in understanding what the AT 100Pro is doing and how it does it In simple D...

Page 19: ... 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 transmitted to reflected energy ...

Page 20: ...es 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 fed dipoles verticals Yagis and in fact virtually any coax fed antenna The series inductors are ...

Page 21: ...to find the best coarse match If no match is found the routine repeats the coarse tuning with the high low impedance relay energized The routine then fine tunes the inductors and capacitors The program checks LC combinations to see if a 1 5 1 or lower SWR can be obtained and stops when it finds a good match The microprocessor runs a fine tune routine just after the tuner finds a match of 1 5 1 or ...

Page 22: ... Toggle Auto Semi Mode Display Auto Semi Selection L Up Scale Increase Inductance Set PWR Meter Scale Display PWR Meter Scale L Dn Thresh Decrease Inductance Set Auto Tuning SWR Threshold Display Auto Tuning SWR Threshold Func Select Secondary Button Functions Display Version Number Func Ant Tune Reset Memory Erase A WORD ABOUT TUNING ETIQUETTE Be sure to use a vacant frequency when tuning With to...

Page 23: ... all of the quality LDG Dealers also ready to help you make that purchase 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 warra...

Page 24: ...can alert you online when your product is en route 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...