LDG IT-100 Operation Manual

IT-100 OPERATIONS MANUAL MANUAL REV A

LDG IT-100

100-Watt Automatic

Tuner for Icom

Transceivers

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LDG Electronics

1445 Parran Road

St. Leonard MD 20685-2903 USA

Phone: [phone]

Fax: [phone]

[e-mail]

www.ldgelectronics.com

Table of Contents

Introduction

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 IT-100 5

Front Panel 5
Rear Panel 6

Installation 7

Compatible Transceivers 7
Installation 7

Operation 8

Power-up 8
Basic Tuning Operation 8
Operation From the ICOM Transceiver Front Panel 8
Operation From the IT-100 Front Panel 9
Toggle Bypass Mode 9
Initiate a Memory Tune Cycle 10
Force a Full Tune Cycle 11
Status LED 12

Operating Hints 12

Transceiver Tuner Status Indication 12
IC-718 Installation 12
Automatic Bypass on Band Change 12

Application Information 12

Mobile Operation 12
MARS/CAP Coverage 14

Theory of Operation 14
The LDG IT-100 16
A Word About Tuning Etiquette 17
Care and Maintenance 17
Technical Support 17
Two-Year Transferrable Warranty 17
Out Of Warranty Service 17
Returning Your Product For Service 18
Product Feedback 18

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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 IT-100 100-watt automatic tuner for Icom transceivers. The
IT-100 provides 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 other
tuners you may have considered, including the built-in tuners on many radios.

The IT-100 is similar to previous LDG tuners, but is specially engineered to integrate with
your Icom HF radio. The IT-100 connects to the external tuner port on the back of the radio. The
IT-100 takes advantage of this interface to simplify the tuning process -- one button push is all
that is needed in order to complete a tuning cycle!

The IT-100 is powered by the transceiver’s tuner interface itself. There is no additional
power cable required to use the IT-100. Latching relays are used, so the IT-100 consumes no
power when not tuning.

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

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

Turn off power to your Icom radio.
Connect the HF/50 MHz antenna jack on the transceiver to the “TX” jack on the IT-100, using a

50 ohm coax cable jumper.

Connect the 50 ohm coax antenna feedline to the “ANT” jack on the IT-100.
Connect one end of the supplied radio interface cable to the tuner port on the back of your radio.
Connect the other end of the supplied radio interface cable to the “Radio” jack on the back of the

IT-100.

Turn on the radio.
Select the desired operating frequency and mode.
Push and hold the TUNER/CALL button on the front of the radio for one second (until the

Tuning LED comes on), then release. The transceiver automatically keys up with a minimal
amount of power, and the IT-100 begins a tuning cycle. At the end of the tuning cycle, the
original mode and power level is restored.

Wait for the tuning cycle to end; you’re now ready to operate!

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SPECIFICATIONS

0.1 to 125 watts SSB and CW peak power, 30 watts on PSK and digital modes, and 100

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watts on 6 meters.
Latching relays for ultra-low power operation.

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2,000 memories for instantaneous frequency and band changing.

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Controlled from ICOM TUNER/CALL button on radio. Powered from ICOM radio.

•

Works with most ICOM radios that are AH-3 or AH-4 compatible.

•

Partial radio list: IC-7000, IC-706 (all), IC-718 (select AH-4), IC-746.

•

Tuning time: 0.1 to 6 seconds full tune, 0.1 seconds memory tune.

•

1.8 to 54.0 MHz coverage. Built-in frequency sensor.

•

Tunes 4 to 800 ohm loads (16 to 150 on 6M), 16 to 3200 ohms with optional 4:1 Balun.

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For dipoles, verticals, Vees, beams or any coax-fed antenna.

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Includes IC-7K interface cable.

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Optional external Balun allows tuning of random length, long wire or ladder line fed

•

antennas. See web site for details.
Dimensions: 7.25”L x 6.25”W x 1.75”H.

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Weight: 1 pound.

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AN IMPORTANT WORD ABOUT POWER LEVELS

The IT-100 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 IT-100. If your 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 IT-100

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

The IT-100 is designed specifically for use with Icom transceivers. Tuning is performed
when the TUNER/CALL button is pushed on the front of the transceiver and held for one
second. The tuner can be placed in bypass mode by pressing the Tune button on the front of the
IT-100 momentarily.

The IT-100 is powered directly from the radio interface cable; no separate power supply is
needed. The IT-100 automatically powers up at the start of a tuning cycle, and then 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 removed. Tuning memories are
stored in FLASH memory.

The IT-100 has 2,000 frequency memories. When tuning on or near a previously tuned
frequency, the IT-100 uses “Memory Tune” to recall the previous tuning parameters in a fraction
of a second. 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
IT-100 “learns” as it is used, adapting to the bands and frequencies as it goes.

Front Panel

On the front panel there is one pushbutton and two LED indicator lights.

Tune Button: Initiates either a memory tune or a full tune, and also toggles the tuner

between “active” and “bypass” modes.

SWR LED: Lights or blinks to indicate SWR condition.

Tuning LED: Lights to give feedback on button presses, lights during tuning; gives tune

status at the end of a tuning cycle.

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Rear Panel

The rear panel of the IT-100 features four connectors.

ANT connector: Connect the 50-ohm coax antenna feedline to this standard SO-239

connector.

to the ANT jack on the back of the transceiver.

GND connector (wing nut): Connect to antenna system ground.
TX connector: Connect a 50 ohm coax jumper cable from this standard SO-239 connector

Radio connector: This 6-pin mini-DIN connector connects to the supplied radio interface

cable, which connects to the AH-4 tuner port on the transceiver. DC power is also supplied over
this jack.

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