LDG RC-100 User manual

RC-100 OPERATIONS MANUAL MANUAL REV A
PAGE 1
LDG RC-100
100-Watt Remote
Tuner Controller
LDG Electronics
1445 Parran Road
St. Leonard MD 20685-2903 USA
Phone: [phone]
Fax: [phone]
[e-mail]
www.ldgelectronics.com

PAGE 2
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 RC-100 5
RC-100 Front Panel 6
RC-100 Rear Panel 6
Installation 7
Basic Installation 7
Operation 8
Power-up 8
Basic Tuning Operation 8
Fully Automatic Memory Tuning 9
Force a Full Tuning Cycle 9
Re-tuning Prohibition 9
A Word About Tuning Etiquette 9
Care and Maintenance 9
Technical Support 10
Two-Year Transferrable Warranty 10
Out Of Warranty Service 10
Returning Your Product For Service 10
Product Feedback 11

PAGE 3
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 RC-100. The RC-100 is the perfect companion to the LDG
Electronics RT-100 100W Remote Automatic Tuner. The RC-100 contains a DC bias tee for
injecting power onto a coax feedline, and provides convenient front panel controls.
The RC-100 simplifies operation of the RT-100 tuner in that it combines the required DC
bias tee with a front panel LED power indicator, Power off/on switch, and a Tune button which
momentarily interrupts power to the RT-100. This is useful for requesting a Full Memory Tuning
sequence from the RT-100. Just key the radio, and push the Tune button momentarily.
JUMPSTART, OR “REAL HAMS DON’T READ MANUALS!”
Ok, but at least read this one section before operating the RC-100:
1. Turn off power to your radio.
2. Connect the antenna jack on the transceiver to the “Radio” jack on the RC-100.
3. Connect the “Tuner” jack of the RC-100 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 RC-100.
6. Begin transmitting; the tuner will automatically begin tuning if there is an SWR mismatch.

PAGE 4
SPECIFICATIONS
•0.1 to 100 watts SSB and CW peak power, 75W on digital modes and 6 meters.
•Power: 12VDC, 500mA
•RF-to-DC isolation: Greater than 45 dB
•1.8 to 54.0 MHz coverage.
•Dimensions: 3.5”L x 3.5”W x 2.0”H.
•Weight: 7.5 oz
AN IMPORTANT WORD ABOUT POWER LEVELS
The RC-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 RC-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.

PAGE 5
GETTING TO KNOW YOUR RC-100
Your RC-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 RC-100 is the perfect companion to the LDG Electronics RT-100 Remote Tuner. The
RT-100 Tuner contains the tuning hardware that performs the real work, and is intended to be
placed nearest to the antenna. The RC-100 contains a bias tee, which injects DC power onto the
coax feedline. The RC-100 also features a Tune button, which is used to request a full tuning
sequence, a Power switch and indicator LED.
The RC-100 powers the RT-100 via injecting 12VDC onto the coax cable, courtesy of the
internal bias tee in the RC-100. 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 Status LED shows that the RC-100 is connected to DC power and is turned on. The
Power button may be used to turn the RC-100 on or off. Pressing the Tune button momentarily
interrupts power to the RT-100 Tuner.

PAGE 6
RC-100 Front Panel
On the front panel of the RC-100, there is one LED and two pushbuttons.
•Status LED: Indicates 12VDC power is applied and Power is ON.
•Power Switch: Turns the tuner on or off.
•Tune Button: Momentarily interrupts power to the RT-100. If pushed and released while
transmitting RF, a full tune is requested.
RC-100 Rear Panel
The rear panel of the RC-100 features three connectors.
•Tuner connector: RF+DC output. Connect a 50-ohm coax feedline from this connector to
the RT-100 Tuner’s “Radio” connector.
•Radio connector: Connect to transceiver’s TX output.
•Power connector: Connect to +12VDC, 500mA, via the supplied DC cable. The center pin
is positive.

PAGE 7
INSTALLATION
The RT-100 tuner is designed for outdoor operation; it is waterproof. However, the RC-100
is not waterproof. If used outdoors (Field Day, for example), the RC-100 must be protected from
rain.
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.
Basic Installation
To add the RC-100 to an RT-100 system, place the RC-100 in a convenient position near the
transceiver’s operating position. Connect a 50-ohm coax jumper from the transceiver’s Antenna
jack to the RC-100’s RADIO jack.
Place the RT-100 Tuner near to the antenna. Connect a short 50-ohm coax jumper from the
RT-100 Tuner’s ANT jack to the antenna. Connect the RT-100 Tuner’s RADIO jack to the RC-
100’s TUNER jack via a length of coaxial cable feedline. LDG recommends grounding the RT-
100 Tuner via the wingnut marked GND.
Connect the RC-100 to a source of 12VDC power, 500 mA, via the supplied DC power
cable. Connect the DC power cable to the POWER jack on the rear of the RC-100. The center
pin is positive.

PAGE 8
NOTE: The RC-100 has no SWR display. If your transceiver does not have a built-in SWR
display, you will need to put an external SWR meter in between the output of the transceiver and
the input of the RC-100:
OPERATION
Power-up
With DC power applied, push the Power button on the front of the RC-100 to turn the system
on. The red Status LED should light. To turn the system off, push the Power button again.
Basic Tuning Operation
Two types of tuning cycles are available; a memory tuning cycle and a full tuning cycle.
The memory tuning cycle attempts to tune quickly based on having previously tuned on the
present frequency selection. If the tuner previously was successful in tuning on the currently
selected frequency, the settings for that match will be loaded into the tuner relays, and checked to
see that an acceptable SWR match is found. If this fails to find a good SWR match, then a full
tuning cycle begins.
A full tuning cycle “starts from scratch” and begins a fixed tuning sequence where the RT-
100 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 cycle.

PAGE 9
In this manner, the RT-100 “learns”; the longer you use it, the more closely it adapts itself to
the bands and frequencies used.
Whenever the RT-100 is powered up, it is in fully automatic Memory Tuning mode. This
means that any time RF is present, if the SWR detected is too high, a memory tuning cycle will
automatically begin.
Most users will probably use memory tuning most of the time; it takes advantage of any
saved tuning settings, but automatically defaults to a full tuning cycle if no stored data is
available.
Fully Automatic Memory Tuning
In order to begin a fully automatic memory tuning cycle, simply tune the radio to the band
and frequency desired, and, while the RT-100 is powered on, simply being transmitting. If a high
SWR condition is detected, the RT-100 Tuner will begin tuning. To watch the progress of the
tuning cycle, keep an eye on your radio’s built-in SWR meter (or external SWR meter, if
applicable). The SWR needle will jump around for a bit and then will settle down to a low SWR
value. Once this happens, tuning is complete. If the tuner is tuning on a previously memorized
frequency, the tuning cycle will only last for a short instant while memory settings are recalled.
Force a Full Tuning Cycle
In some instances, you may wish to force the RT-100 to begin a full tuning cycle instead of
just the usual memory cycle. In order to do this, begin transmitting a carrier, and while still
keying the radio, push the Tune button on the RC-100 for one second and release. Continue
transmitting the tuning carrier until the SWR settles to a low value.
Re-tuning Prohibition
In some rare cases, when an antenna is tuned far from its resonant frequency, the RT-100
may erroneously continue to attempt to re-tune, even though it has already found a good match
for the current antenna and frequency. In these cases, if the RT-100 decided to re-tune after it has
already found a good match, simply turn the RT-100 off, by pushing the Power button on the
front panel of the RC-100. The latching relays inside the tuner will keep the current match
settings even with power off, but the tuner will stop attempting to re-tune.
A WORD ABOUT TUNING ETIQUETTE
Be sure to use a vacant frequency when tuning. With today’s crowded ham bands, this is
often difficult. However, causing interference to other hams should be avoided as much as
possible. The RT-100’s very short tuning cycle minimizes the impact of tuning transmissions.
CARE AND MAINTENANCE
The RC-100 is essentially maintenance-free. Power limits in this manual should be strictly
adhered to. The outer case may be cleaned as needed with a soft cloth slightly dampened with
household cleaning solution. As with any modern electronic device, the RC-100 can be damaged
by temperature extremes, water, impact, or static discharge. LDG strongly recommends the use
of a good quality, properly installed lightning arrestor in the antenna lead.

PAGE 10
TECHNICAL SUPPORT
The LDG customer support staff is ready to answer your product question by telephone and
by e-mail. We know that you will enjoy your product even more knowing LDG is ready to
answer your questions as the need arises.
LDG regularly updates on-line information so the best on-line support information is
available all day and every day.
The LDG website provides links to product manuals, just in case you lose this one! When
you are thinking about the purchase of other LDG products our website also has complete
product specifications and photographs you can use to help make your purchase decision. Don’t
forget the links to 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 warranty goes with the new owner.
There is no need to complete a warranty card or to register an LDG product. Your product
receipt establishes eligibility for warranty service, so save that receipt. Send your receipt with the
product whenever you send your product to LDG for repair. Products sent to LDG without a
receipt are considered requests for out-of-warranty repair.
LDG does not warranty against product damage or abuse. This means that a product failure,
as determined by LDG, to be caused by the customer or by other natural calamity (e.g. lightning)
is not covered under the two-year warranty. Damage can be caused by failure to heed the
product’s published limitations and specifications or by not following good Amateur practice.
OUT OF WARRANTY SERVICE
If a product fails after the warranty period, LDG wants to help you get it fixed. Send the
product to us for repair any time you like. We will determine what needs to be done and based on
your instructions, either contact you with an estimate or fix it and contact you with a request to
pay any repair charges. Please contact LDG if you have any questions before you send us an out-
of-warranty product for repair.
RETURNING YOUR PRODUCT FOR SERVICE
Returning a product to LDG is easy. We do not require a return merchandise authorization,
and there is no need to contact LDG to return your product. Visit the LDG web site and
download the LDG Product Repair Form. On the Repair Form tell the LDG technicians exactly
what happened or didn’t happen and why you believe the product needs servicing. The
technician attempts to duplicate the problem(s) you had based on how well you describe it so
take the time to be accurate and complete.
Ask your shipper for a tracking number or a delivery verification receipt. This way you know
the product arrived safely at LDG. Be sure to give us your email address so our shipper can alert

PAGE 11
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 on the LDG website under Support, then Tech Support.
Send your carefully packaged unit with the Repair Form to:
LDG Electronics, Inc.
Attn: Repair Department
1445 Parran Rd
St. Leonard, MD 20685
PRODUCT FEEDBACK
We encourage product feedback! Tell us what you really think of your LDG product. In a
card, letter, or email (preferred) tell us how you used the product and how well it worked in your
application. Send along a photo or even a schematic or drawing to illustrate your narrative. We
like to share your comments with our staff, our dealers, and even other customers at the LDG
website:
http://www.ldgelectronics.com/

RC-100 OPERATIONS MANUAL MANUAL REV A
PAGE1
LDG RC-100
Automatic Tuner
Remote Controller
LDG Electronics
1445 Parran Road
St. Leonard MD 20685-2903 USA
Phone: [phone]
Fax: [phone]
[email protected]
www.ldgelectronics.com

Table Of Contents
Introduction!3
Jumpstart, or “Real hams don’t read manuals!”!3
Specifications!4
Important Safety Warning!4
Getting to know your RC-100!5
Installation!6
Operation!7
The LDG RC-100!8
A Word About Tuning Etiquette!8
Care and Maintenance!8
Technical Support!8
Two-Year Transferrable Warranty!8
Out Of Warranty Service !9
Returning Your Product For Service!9
Product Feedback!10
PAGE2

INTRODUCTION
Congratulations on selecting the LDG RC-100 remote controller. The RC-100 works with the
RT-100 remote automatic tuner, providing DC power insertion, On/Off switching, manual Tune
functions, and status indication. Installed near your operating position, it provides full control of
your RT-100 tuner.
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.
JUMPSTART, OR “REAL HAMS DON’T READ MANUALS!”
Ok, but at least read this one section before operating the RC-100 (this Jumpstart describes
use of the RC-100 with an RT-100 tuner):
1. Turn off your radio.
2. Connect the antenna jack on the transceiver to the Radio jack on the RC-100.
3. Connect the Tuner jack on the RC-100 to the Radio jack on the RT-100 via a suitable length
of coax 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 RC-100. Observe polarity;
center pin positive.
6. Press the Power button on the RC-100 to provide power to the RT-100 tuner.
7. Turn on your radio and begin transmitting normally; the tuner will automatically initiate a
tuning cycle if there is an SWR mismatch.
PAGE3

SPECIFICATIONS
• DC power input: 12VDC, 500mA
• Operating temperature range: 0ºF-110ºF (-18ºC - +43ºC)
• Provides DC power injection, On/Off switch, Tune button, and Status indication.
• Dimensions: 3.5”L x 3.5”W x 2”H.
• Weight: 7 oz.
IMPORTANT SAFETY WARNING
Never install antennas or transmission lines over or near power lines. You can be
seriously injured or instantly 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 overhead power lines should be at least twice the length of the longest antenna,
transmission line or support dimension.
PAGE4

GETTING TO KNOW YOUR RC-100
Your RC-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 RC-100 is designed to be installed near your operating position, providing complete
control of your RT-100 remote tuner. The RC-100 contains a “Bias Tee” circuit, powering your
RT-100 tuner via the coax cable; no separate power cable is required.
The RC-100 has two controls: Power and Tune. Power turns DC power to the RT-100 on
and off. The RT-100 features latching relays, so the tuned state is retained indefinitely even when
the power is turned off. The Tu ne button initiates a semi-automatic tuning cycle.
The RC-100 has one indicator light, the Status light, which indicates the state of the tuner.
There are three connectors on the rear panel: Tuner, Radio and Power. The Radio port
connects to your transceiver or transmitter. The Tuner port connects to the coax going to the
RT-100. Power connects to a DC power source capable of providing 12 volts DC at 500 ma.
Important Note: The transmission line between the RC-100 and the RT-100 tuner must never be
grounded. Doing so would cause the RC-100 to attempt to source 12 vdc directly to ground,
damaging the unit. Never use coax switches that ground unselected ports even momentarily.
PAGE5

INSTALLATION
The RT-100 tuner is designed for indoor operation; it is not water-resistant. If you use your
RT-100 outdoors (Field Day, for example) you must protect it from rain or other sources of water.
The RC-100 is designed to feed the RT-100 with coax cable; ladder line or other types of
transmission line should not be used between the RC-100 and the RT-100. However, the RT-100
can feed the antenna via ladder line with the use of a suitable balun.
Always turn your radio off before plugging or unplugging any external devices. The radio
may be damaged if cables are connected or disconnected while the power is on.
Install your RC-100 near your operating position
Your RC-100 is designed to be used within easy reach of your operating position. Select a
location where you can access the controls and see the Status light. Also consider the two coax
cable and power lead runs when selecting a location.
Connect to Transceiver and Antenna
Connect the Radio jack of your RC-100 to your tranceiver or transmitter with length of
suitable 50 ohm coax cable, usually RG-8, RG-58 or similar. Make the coax as short as practical.
Connect the coax cable leading to the RT-100 tuner to the Tuner port.
Connect a source of 12VDC power capable of providing 500 mA to the Power jack with the
provided coaxial power plug. Be sure to observe polarity; the center pin is positive. A regulated
power supply is recommended, but is not required.
PAGE6

OPERATION
Automatic Operation
Your will probably use your RT-100 remote tuner in fully automatic memory mode most of
the time. Simply press the Power button on the RC-100 to provide DC power to the tuner; the
RT-100 “wakes up” in automatic memory mode. Operate normally, and the RT-100 will maintain
an SWR of about 1.7 or less on all frequencies within its specifications without your
intervention, tuning as necessary as you operate.
Force a Full Tuning Cycle
In some instances you may wish to force the RT-100 to begin a full tuning cycle instead of
the usual automatic memory cycle. Transmit a carrier, press the Tun e button on the RC-100 for
one second then release. Continue transmitting the tuning carrier until the tuning cycle ends.
Re-tuning Termination
When an antenna is used far from its resonant frequency, the RT-100 may erroneously
continue a tuning cycle, even though it has already found a good match for the current antenna
and frequency. This is a rare event; you’re not likely to encounter it. If this happens, simply turn
the RT-100 off by by pressing the Power button on the RC-100 (button out). The latching relays
in the tuner will keep the current match settings even with power off, but the tuner will stop
attempting to re-tune. Press the Power button again to turn the DC power back on (button in) and
resume normal operation.
Recovering from a “hang-up”
On rare occasions your RT-100 may seem to “hang”, and stop operating correctly. In that
case follow these steps to recover normal operation:
• Put your radio in AM mode
• Push the PTT and hold it
• Press the Tune button on the RC-100 and hold for 2 seconds, then release
• Keep the PTT pressed while the tuner tunes
• When tuning cycle ends, check for good SWR, then release PTT
• Resume normal operation
PAGE7

THE LDG RC-100
In 1995 LDG Electronics pioneered a new type of automatic antenna tuner. The LDG design
uses banks of fixed capacitors and inductors, switched in and out of the circuit by relays under
microprocessor control. The RC-100 is custom designed to work with and compliment operation
of the RT-100 remote tuner.
The relays in the RT-100 remote tuner are powered by the 12VDC supplied over the coax
cable via a Bias Tee curcuit included in the RC-100. The Bias Tee allows both RF and DC to be
carried over the same conductor. This arrangement is virtually lossless and has no effect on
SWR.
A WORD ABOUT TUNING ETIQUETTE
Be sure to use a vacant frequency when tuning. With today’s crowded ham bands, this is
often difficult. However, causing interference to other hams should be avoided as much as
possible. The LDG tuner’s very short tuning cycle minimizes the impact of tuning transmissions.
CARE AND MAINTENANCE
The RC-100 remote control is essentially maintenance-free. The outer case may be cleaned
as needed with a soft cloth slightly dampened with household cleaning solution. As with any
modern electronic device, the RC-100 can be damaged by temperature extremes, impact, or static
discharge. LDG strongly recommends the use of a good quality, properly installed lightning
arrestor in the antenna lead.
TECHNICAL SUPPORT
The LDG customer support staff is ready to answer your product question by telephone and
by e-mail. We know that you will enjoy your product even more knowing LDG is ready to
answer your questions as the need arises.
LDG regularly updates on-line information so the best on-line support information is
available all day and every day.
The LDG website provides links to product manuals, just in case you lose this one! When
you are thinking about the purchase of other LDG products our website also has complete
product specifications and photographs you can use to help make your purchase decision. Don’t
forget the links to 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 warranty goes with the product to the new owner.
PAGE8

There is no need to complete a warranty card or to register an LDG product. Your product
receipt establishes eligibility for warranty service, so save that receipt. Send your receipt with the
product whenever you send your product to LDG for repair. Products sent to LDG without a
receipt are considered requests for out-of-warranty repair.
LDG does not warranty against product damage or abuse. This means that a product failure,
as determined by LDG, to be caused by the customer or by other natural calamity (e.g. lightning)
is not covered under the two-year warranty. Damage can be caused by failure to heed the
product’s published limitations and specifications or by not following good Amateur practice.
OUT OF WARRANTY SERVICE
If a product fails after the warranty period, LDG is here to help you get it fixed. Send the
product to us for repair any time you like. We will determine what needs to be done and based on
your instructions, either contact you with an estimate or fix it and contact you with a request to
pay any repair charges. Please contact LDG if you have any questions before you send us an out-
of-warranty product for repair.
RETURNING YOUR PRODUCT FOR SERVICE
Returning a product to LDG is easy. We do not require a return merchandise authorization,
and there is no need to contact LDG to return your product. Visit the LDG web site and
download the LDG Product Repair Form. On the Repair Form tell the LDG technicians exactly
what happened or didn’t happen and why you believe the product needs servicing. The
technician attempts to duplicate the problem(s) you had based on how well you describe it so
take the time to be accurate and complete.
Ask your shipper for a tracking number or a delivery verification receipt. This way you know
the product arrived safely at LDG. Be sure to give us your email address so our shipper 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 on the LDG website under Support, then Tech Support.
Send your carefully packaged unit with the Repair Form to:
LDG Electronics, Inc.
Attn: Repair Department
1445 Parran Rd
St. Leonard, MD 2068
PAGE9