LDG JT-11 User Manual

JT-11

Automatic Antenna Tuner

For Ten-Tec Jupiter

Manual Version 1.0

LDG Electronics

1445 Parran Road, PO Box 48

St. Leonard MD 20685-2903 USA

Phone: [phone] Fax: 410-

586-8475

www.ldgelectronics.com

[e-mail]

Copyright © LDG Electronics 2005. All rights reserved.

JT-11

Automatic Antenna Tuner

For the Ten-Tec Jupiter

Introduction 3
Specifications 3
JT-11 Auto Tuner Overview 4
Installation 6
Operation 10
Theory Of Operation 11

Some Basic Ideas About Impedance 11
Transmitters, Transmission Lines, Antennas and Impedance 11

The LDG JT-11 12
A Word About Tuning Etiquette 14
Care and Maintenance 14
Technical Support 14
Warranty and Service 14
Firmware Upgrades 15
Feedback 15

2

Introduction

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Congratulations on selecting the JT-11 tuner for your Ten-Tec Jupiter transceiver. This tuner,
when installed, will be fully integrated with your transceiver, and will be controlled by the radio's
user interface. Your JT-11 will quickly and automatically match an amazing variety of antennas.

LDG pioneered the automatic, wide-range switched-L tuner in 1995. From its laboratories near
the nation’s capitol, LDG continues to define the state of the art in this field with innovative
automatic tuners and related products for every amateur need.

Specifications

•

Fully integrated with the Jupiter transceiver

• 200 memories for instantaneous frequency or band changing

• Automatic reset of last tuned setting on power-up

• Tuning time: 0.1 to 4 seconds full tune, < 0.1 second memory tune

• Frequency coverage: 1.8 to 30.0 MHz.

• Tunes 6 to 1000 ohm loads, 32 to 4000 ohms with optional external 4:1 Balun

(LDG RBA-4:1)

• For Dipoles, Verticals, Vs, Beams or and Coax Fed Antenna

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

fed antennas

• Powered directly by the Jupiter radio

Never install antennas or transmission lines over or near
power lines. You can be seriousl
of the antenna, support or transmission line touches a power
line. Alwa
the nearest power line should be at least twice the len
the longest antenna, transmission line or support dimension.

IMPORTANT SAFETY WARNING

injured or killed if any part

s follow this antenna safety rule: the distance to

th o

3

JT-11 Auto Tuner Overview

Your JT-11 comes fully assembled, aligned and mounted in its own shield enclosure. You will
install the tuner inside your Jupiter transceiver, resulting in a fully integrated internal tuner. After
installation, your JT-11 tuner will be controlled by the Jupiter's user interface.

Installation is straightforward; you will mount the tuner inside your Jupiter transceiver, remove
one coax cable and solder four connections.

Installation requires that you un

solder two existing coaxial connections and make three new
solder connections. These are simple steps, well within the abilities of anyone with basic
electronic assembly skills. Simply follow the step-by-step directions, referring to the
accompanying illustrations. Work patiently, read through each step completely before proceeding
and check your work often.

Your workplace should be uncluttered, well lighted and well ventilated, and protected from static
discharge. A grounded static mat is ideal, but you should at least be able to touch a ground point
(light switch, water pipe, etc) from time to time to avoid static buildup.

Installing the JT-11 according to these instructions does not void your Ten-Tec warranty.

4

A word about power levels

Your JT-11 is custom designed specifically for the Jupiter transceiver and its power levels. When
used with the Jupiter, the RF power will automatically be lowered to approximately 20 watts
during the tuning cycle.

LDG does not recommend using the JT-11 in any other application. If you choose to do so, never
exceed 125 watts peak power input to the tuner. A minimum of 0.1 watts is required to activate
the tuner.

Required Tools:

You will need a few basic electronic assembly tools to install your JT-11:

Small soldering iron, 25-40 watts (a temperature-controlled iron is preferred)
Rosin-core or other solder intended for electronic assembly (NEVER use acid core solder for
electronic assembly)
“Solder Wick” solder removal material, or “solder sucker” solder removal tool
Medium Phillips screwdriver, small hex or star driver
Small pliers
Small wire cutters

A few words about soldering and unsoldering:

In one step, you will be instructed to “tack solder” a wire. This refers to soldering a wire end to a
pad on the PC board where there is no available hole. Simply hold the wire against the pad, heat
with your soldering iron, and apply a small amount of solder. Hold the wire in place until the
solder cools. It will help to tin the wire first, flowing solder onto the wire before soldering it into
place.

In installing your JT-11, you will unsolder two coaxial cable connections on your Jupiter; you
must remove the excess solder from these connections. You have two options: Solder Wick or a
“Solder Sucker” solder removal tool. Solder Wick is a metal braid impregnated with rosin. Place
the end of the Solder Wick against the connection to be unsoldered and heat the wick with your
soldering iron; the wick will conduct the heat to the solder connection. As the solder melts, the
wick will absorb it; cut off and discard the used end of the wick and continue until all excess
solder is removed.

A “Solder Sucker” is a spring-loaded vacuum syringe with a heat-resistant tip. Cock the spring
plunger, and press the tip against the connection along with your soldering iron. When the solder
melts, trigger the Solder Sucker; the spring-loaded syringe will pop up, drawing the molten solder
into the tip. Do this with care, as the jolt of the spring could dislodge your soldering iron. Practice
a few times with a cold iron to get the feel of it.

5