LDG Electronics AT-100PROII Instructions manual

AT-100PROII OPERATIONS MANUAL MANUAL REV A

LDG AT-100ProII

100W Automatic

Antenna Tuner

LDG Electronics

1445 Parran Road

St. Leonard MD 20685-2903 USA

Phone: [phone]

Fax: [phone]

[e-mail]

www.ldgelectronics.com

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Table Of Contents

Introduction 3
Jumpstart, or “Real hams don’t read manuals!” 3
Specifications 4
An Important Word About Power Levels 4
Important Safety Warning 4
Getting to know your AT-100ProII 5

Front Panel: 5
Back Panel: 6

Installation 7
BASIC Operation 9

Using the Front Panel Buttons 9
User Configuration Options 9
Transmitting and Receiving 12

Tuning 13

Basic Tuning Operation 13
Manual Memory Tune 13
Manual Full Tune 14
Bypass Mode 14
Error Indication 15

Advanced Operation 17

Manual Inductor/Capacitor Adjustments 17
High/Low Impedance Relay Adjustment 17
Manual Memory Store 17
Status Check 17

Application Notes 18

Mobile Operation 18
Conserving Power When Operating on Batteries 19
Internally Generated RF Noise 19
MARS/CAP Coverage 19

Theory of Operation 19

Some basic ideas about impedance 19
Transmitters, transmission lines, antennas, and impedance 20

The LDG AT-100ProII 21
Quick Reference 23
A Word About Tuning Etiquette 24
Care and Maintenance 24
Technical Support 24
Two-Year Transferrable Warranty 24
Out Of Warranty Service 25
Returning Your Product For Service 25
Product Feedback 25

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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.

Congratulations on selecting the LDG Electronics AT-100ProII 100-watt automatic tuner.
The AT-100ProII provides fully- and semi-automatic antenna tuning across the entire HF
spectrum plus 6 meters, at power levels up to 125 watts. It will tune dipoles, verticals, Yagis, or
virtually any coax-fed antenna. It will match an amazing range of antennas and impedances, far
greater than some tuners you may have considered, including the built-in tuners on many
transceivers.

The AT-100ProII uses latching relays and other power-saving techniques to consume very
little power when not tuning, making it suitable for battery-powered operation.

JUMPSTART, OR “REAL HAMS DON’T READ MANUALS!”

Ok, but at least read this one section before operating the AT-100ProII:

Connect a 50-ohm coax jumper cable from the antenna jack on your transceiver to the TX jack on

the back of the AT-100ProII.

Connect your antenna’s 50-ohm coax feedline to the ANT 1 jack on the rear of the AT-100ProII.
Connect the supplied DC coax cable to the jack marked 12 VDC. Connect this cable to a DC source

between 11 and 16 volts DC, 500 mA. The jack center tip is positive.

Power up the transceiver, and select the desired operating frequency and mode.

1

Begin transmitting, any mode

.

When the tuning cycle completes, you’re ready to operate!

1 In SSB mode, simply speak into the microphone while transmitting. Tuning may be performed at up to 125 watts of input power, provided that the transceiver
employs a “roll-back” circuit to protect it from high SWR. For transceivers without roll-back circuits, power should be limited to 25 watts when tuning, to avoid
damage to the transmitter or tuner.

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SPECIFICATIONS

1.0 to 125 watt power range (SSB and CW), 100W on 6M.
Latching relays for ultra low power operation.
4,000 memories for instantaneous band changing.
Built-in 2-port antenna switch, with 2,000 memories each.
Tuning time 0.2 to 5 seconds full tune, 0.2 seconds memory tune.

1.8 to 54.0 MHz coverage. Built-in frequency sensor.
Tunes 6 to 1,000 ohm loads (16 to 150 on 6m).
LED bargraph displays power level, SWR, and status.
Antenna Indicator LEDs show the currently selected antenna.
User-selectable operating parameters: Auto/Semi, 125/12.5 watt scale, and more.
DC power cable included.
Power requirements: 11 to 16 VDC @ 500mA max. 7mA when idle.
Dimensions: 7.5” x 5.5” x 2.0”. Weight 1.5 pounds.

AN IMPORTANT WORD ABOUT POWER LEVELS

The AT-100ProII 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 AT­100ProII. If the tuner fails during overload, it could also damage your transmitter or transceiver.
Be sure to observe the specified power limitations.

IMPORTANT SAFETY WARNING

Never install antennas or transmission lines over or near power lines. You can be
seriously injured or killed if any part of the antenna, support, or transmission line touches
a power line. Always follow this antenna safety rule: The distance to the nearest power line
should be at least twice the length of the longest antenna, transmission line, or support
dimension.

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GETTING TO KNOW YOUR AT-100PROII

Your AT-100ProII is a quality, precision instrument that will give you many years of
outstanding service; take a few minutes to get to know it.

Front Panel:

The front panel of the AT-100ProII features seven pushbuttons, two LED bargraph scales,
and two antenna indicator LEDs:

Func: Activates secondary function of other buttons.
Ant: Selects the active antenna port.
C Up: Manually increase capacitance.
C Dn: Manually decrease capacitance.
L Up: Manually increase inductance.
L Dn: Manually decrease inductance.
Tune: Initiates memory or full tuning cycle. 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.
Bypass LED: Lights when in bypass mode.
ANT 2 LED: Lights when Antenna 2 is selected.

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.

There is no power button on the AT-100ProII. When the tuner is idle, it enters a low-power
sleep mode, drawing very little current. When the tuner detects a button press or an RF
transmission, it “wakes up,” ready to act.

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Back Panel:

The rear panel of the AT-100ProII has six jacks.

Ant 1: Connect a 50 ohm 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: Connect the optional radio interface cable to a supported ICOM or Yaesu radio.

Power: Connect the supplied DC coaxial power cable to this connector, and connect to a source

of 11-16 VDC @ 500 mA. Center pin is positive.

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Installation

The AT-100ProII is intended for indoor use only; it is not water-resistant. If you use it
outdoors, (DXpedition to Bimini Island, for example) you must protect it from the weather. The
AT-100ProII is designed for use with coax-fed antennas. If use with longwires or ladder-line-fed
antennas is desired, an external balun is required. The LDG RBA-4:1 or RBA-1:1 is ideal,
depending on the antenna and transmission line used.

Place the AT-100ProII in a convenient location near the transceiver. Always turn your radio
off before plugging or unplugging anything. The radio may be damaged if cables are connected
or disconnected while the power is on.

Connect the HF antenna jack on the transceiver to the TX jack on the back of the AT­100ProII, using a 50 ohm coax cable rated 125 watts or higher.

Connect a 50-ohm antenna feedline coax to the ANT 1 jack on the back of the AT-100Plus,
and optionally connect a second antenna feedline to the ANT 2 jack.

The AT-100ProII is designed to interface directly with many popular ICOM and Yaesu
transceivers, enabling one button tuning. In the case of ICOM radios, the interface cable also
powers the tuner.

For ICOM radios supporting the AH-3 or AH-4 external tuner, connect the 4-pin Molex
connector of the optional 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-100ProII. 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 the optional Y-ACC cable and plug the red end marked
Radio into the transceiver’s ACC port. Plug the black end of the Y-ACC cable into the jack
marked Radio on the rear of the AT-100ProII.

Unless the AT-100ProII is being powered by the ICOM radio interface cable as above, you’ll
also need to plug in the supplied DC coaxial power cable. This cable has a 2.5x5.5mm coaxial
plug on the end. Plug the coaxial plug into the 12 VDC Power jack on the rear of the AT-
100ProII, and connect the other end to a DC power source between 11 and 16 volts DC, capable
of supplying up to 500 mA.

Grounding the AT-100ProII tuner will enhance its performance and safety. LDG
recommends that you connect your tuner to a suitable ground. A common ground rod connected
to buried radials is ideal, but a single ground rod, a cold water pipe, or the screw that holds the
cover on an AC outlet can provide a serviceable ground. LDG strongly recommends the use of a
properly installed, high quality lightning arrestor on all antenna cables.

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