LDG RT-100 Operation Manual

RT-100 OPERATIONS MANUAL MANUAL REV A

LDG RT-100

100-Watt Remote

Automatic 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 RT-100 5

RT-100 Connections 6

Installation 7

Connections 7
Installing Into An Existing Outdoor Antenna Installation 8
Tips for Outdoor Installation 8
Securing the RT-100 to a Mast 10

Bias Tee Information 11
Operation 12

Basic Tuning Operation 12
Fully Automatic Memory Tuning 12
Force a Full Tuning Cycle 12
Re-tuning Prohibition 12
MARS/CAP Coverage 13

The LDG RT-100 13
A Word About Tuning Etiquette 14
Care and Maintenance 14
Technical Support 14
Two-Year Transferrable Warranty 14
Out Of Warranty Service 15
Returning Your Product For Service 15
Product Feedback 16

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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 RT-100 100-watt remote automatic tuner. The RT-100
provides full- and semi-automatic antenna tuning across the entire HF spectrum plus 6 meters, at
power levels up to 100 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 RT-100 is similar to previous LDG tuners, but is powered over coax, so that the tuner
element may be placed as near to the antenna as possible. The tuner element is powered over the
coax feedline by means of a built-in bias tee, so no additional cables are required in order to
place the tuner at the antenna end of the feedline. By placing the tuner as close to the antenna as
possible, SWR losses over the length of the feedline are minimized.

The optional RC-100 control unit for the RT-100 provides DC power injection via a bias tee,
as well as a convenient on/off switch, power indicator, and TUNE button, which momentarily
interrupts power to the RT-100.

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

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

1. Turn off power to your radio.

2. Connect the antenna jack on the transceiver to the “Radio” jack on the optional RC-100 or

the “RF” jack of a bias tee (not included).

3. Connect the “Tuner” jack of the optional RC-100 or “RF+DC” jack of a bias tee to the

“Radio” jack on the RT-100, via your antenna’s existing feedline.

4. Connect the antenna to the “Ant” jack on the RT-100.

5. Connect a source of 12VDC, 500mA to the Power jack on the optional RC-100 or the bias

tee.

6. Begin transmitting; the tuner will automatically begin tuning if there is an SWR mismatch.

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SPECIFICATIONS

0.1 to 100 watts SSB and CW peak power, 30W on digital modes.

•

Latching relays for ultra-low power operation.

•

2,000+ memories for instantaneous frequency and band changing.

•

Power: 12VDC, 500mA, extracted from the coax feedline via built-in bias tee. (DC

•

injection bias tee not included)

1.8 to 54.0 MHz coverage.

•

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

•

For Dipoles, Verticals, Vees, Beams or any Coax Fed Antenna.

•

Water-resistant case and rubber gaskets. Non-immersible.

•

Operating temperature range: 0F-110F (-18C - 43C)

•

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

•

antennas.
Optional RC-100 controller provides DC power injection, On/Off switch, and Tune button.

•

Dimensions: 7.0”L x 5.5”W x 3.5”H.

•

Weight: 1 lb, 0 oz.

•

AN IMPORTANT WORD ABOUT POWER LEVELS

The RT-100 is rated at 125 watts maximum power input at most. Many ham transmitters and
transceivers, and virtually all amplifiers, are capable of transmitting well over 125 watts. Power
levels that significantly exceed specifications will definitely damage or destroy your RT-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 RT-100

Your RT-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 RT-100 tuner is designed to be used as a remote antenna tuner, powered over a single
coax cable that carries both the RF energy and DC power. An on-board bias tee separates the RF
from the DC power. In order to power the RT-100, a separate bias tee must be used to inject DC
power at the feed end of the coax. Alternately, the optional RC-100 Controller unit may be used.
It contains not only a DC bias tee for injecting power, but also an Off/On power button, LED
power indicator, and a Tune button which momentarily interrupts power to the RT-100.

The RT-100 is powered via 12VDC, which is supplied over the same coax cable used for the
antenna feedline. A bias tee or optional RC-100 is needed at the radio end of the cable, to inject
DC power onto the feedline. Because power is supplied over coax, the existing coax feedline to
your antenna is all you need to hook up the RT-100. No additional cables are required in order to
run power or control signals to the tuner.

The RT-100 has 2,000 frequency memories. When tuning on or near a previously tuned
frequency, the RT-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 RT-100 “learns” as it is used, adapting to the bands and frequencies as it goes. The
RT-100’s latching relays hold the tuned configuration indefinitely, even when DC power is
completely removed. Tuning memories are stored in non-volatile FLASH memory.

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