RadioShack FM Mobile Transceiver HTX 252 Owners Manual

							Cat. No. 19-1127
OWNER’S MANUAL
Please read before using this equipment.
HTX-252
2–Meter Amateur
FM Mobile Transceiver 
						

							2
FEATURES
Your RadioShack HTX-252 2–Meter FM Mobile Transceiver is a
compact and versatile transceiver, perfect either in your vehicle
or in your home. Vehicle cables and mounting hardware are sup-
plied. Add an optional base-station antenna, cable, and a power
supply to make it your home transceiver. It is an all-around ideal
choice for your amateur communications needs.
Note: You must have a Technician Class or higher Amateur Ra-
dio Operator’s License and a call sign issued by the FCC to legal-
ly transmit using this transceiver. Transmitting without a license
carries heavy penalties. Getting a license is easier than ever. See
“Introduction to Amateur Radio” on Page 7 for more information.
Here are some of your transceiver’s features.
High (25 Watt) and Low (10 Watt) Power Settings — let you se-
lect the best power setting according to communication guide-
lines.
10 Memory Channels and 1 Call Channel — let you store up to
10 frequencies for quick access along with other settings such as
the repeater offset and the CTCSS tones.
Frequency Range of 144–148 MHz (TX) and 136–174 MHz
(RX) —
 provide flexibility and excellent wide coverage. You can
also extend the transmit frequency range to 142.00–
149.885MHz.
Channel Up/Down and 16-Key DTMF on the Mic — lets you
manually send DTMF (Dual-Tone, Multiple Frequency) tones to
quickly access DTMF-access repeaters, autopatches, or other
stations equipped with a DTMF page feature.
CTCSS (Continuous Tone Coded Squelch System) 
Subaudible
Tone — both encodes and decodes 38 subaudible tones to help
reduce interference from other nearby systems operating on the
same frequency.
©2000 Tandy Corporation.
All Rights Reserved.
RadioShack is a registered trademark used by Tandy Corporation. 
						

							3
Programmable Frequency Step — lets you set the frequency
step for tuning or scanning to 5, 10, 12.5, 15, 20, 25 kHz.
Signal Strength Indicator — a graduated bar shows the relative
strength of the received signal and transmitting signal.
Digital Phase-Locked Loop (PLL) Frequency Synthesizer —
provides highly accurate and stable tuning.
Built-In Automatic Modulation Control — ensures a constant
RF modulation level.
Repeater Offset — lets you select the appropriate offset value to
match a local repeater.
Scan — the transceiver scans the frequency range and the mem-
ory locations for transmissions.
Rotary Tuning — lets you reach a desired frequency quickly and
accurately.
External Speaker Jack — lets you connect an optional external
speaker for more flexible operation.
Illuminated Digital Display — clearly shows the frequency, the
functions, and the signal strength.
Key Lock — lets you lock the transceiver’s keys to prevent acci-
dentally changing settings. 
						

							4
MANUAL CONVENTIONS
Some of your transceiver’s controls perform multiple functions.
The abbreviation or symbol for a function is printed on, or above
each multi-function button.
To activate certain transceiver features, you must press 
F (func-
tion)
 and then another button. Those key combination instruc-
tions are printed as the first button name, +, then the second
button name. For example, 
F+LOCK means press F then press
LOCK.
Control names are printed in small, bold, capital letters such as
CALL or VFO. Words, symbols, and numbers that appear on the
display are printed using a distinctive typeface, such as
 
146.94
or
 BUSY. 
FCC INFORMATION
This device complies with Part 15 of the FCC Rules. Operation is
subject to the following two conditions: (1) This device may not
cause harmful interference, and (2) this device must accept any
interference received, including interference that may cause un-
desired operation. 
						

							5
CONTENTS
Introduction to Amateur Radio  .............................................  7
Preparation  .............................................................................  9
Attaching the Microphone Holder  .....................................  9
Mounting the Transceiver  .................................................  9
Connecting an Antenna  ................................................... 11
Connecting the Microphone  ............................................  12
Using an External Speaker  .............................................  12
Connecting Power  ..........................................................  13
Using the Transceiver as a Base Station  ........................  13
A Quick Look at the Controls  .............................................  15
A Quick Look at the Display  ...............................................  18
Operation  ..............................................................................  19
Turning the Transceiver On and Off ................................  19
Selecting Frequencies  ....................................................  19
Receiving Transmissions  ................................................  20
Transmitting  ....................................................................  20
Understanding Repeaters  ...................................................  22
Setting the Repeater Offset Frequency  ..........................  23
Setting the Repeater Offset Direction  .............................  23
Reversing the Transmit and Receive Frequencies  .........  24
Memory Operation  ...............................................................  25
Storing a Transmit/Receive Frequency ...........................  25
Recalling Memories  ........................................................  25
Using the Calling-Frequency Memory  ............................  26
Scanning Operation  .............................................................  27
Scanning for Active Frequencies  ....................................  27
Scanning Standard Memory Locations  ...........................  27
Continuous Tone Coded Squelch System Features  .........  28
Temporarily Opening Squelch .........................................  28
Using DTMF Tones  ...............................................................  30 
						

							6
Other Special features  .........................................................  31
Using Priority Frequency Monitor  ....................................  31
Using VFO Priority  ...................................................  31
Using Memory Priority  ..............................................  31
Changing the Transmit Frequency Range  ......................  32
Selecting the Transmit Power Level  ................................  32
Locking the Keypad  .........................................................  32
Turning the Key Tone On and Off  ....................................  33
Setting the Frequency Step  .............................................  33
Reducing Interference  .....................................................  33
Troubleshooting  ...................................................................  35
Care and Maintenance  .........................................................  36
Resetting the Transceiver  ...............................................  37
Replacing the In-Line Fuse  .............................................  37
Specifications  .......................................................................  38 
						

							7
INTRODUCTION TO AMATEUR RADIO
This transceiver is the perfect first radio for anyone entering the
exciting world of amateur radio, as well as a great additional
transceiver for the experienced amateur radio operator. This
transceiver opens a door for you to the world from almost any-
where! All you need is an Amateur Radio Operator’s License
(Technician Class or higher) issued by the Federal Communica-
tions Commission (FCC). If you do not have a license, it is easier
than ever to get one, and help from licensed operators is avail-
able. Here are a few tips to help you get started.
You can turn on your transceiver and scan the entire band to hear
what is going on; 
however, do not attempt to transmit until
you get your license. If you transmit without a license, you are
in violation of federal law that can lead to severe penalties. Note
that ham operators take the FCC rules very seriously and want
nothing to do with “bootleggers” — their term for people who op-
erate without a license.
Find out if there is a ham radio club in your area. Most clubs wel-
come newcomers and are glad to help you get your license.
There are thousands of clubs across the country, so there is prob-
ably one in or near your community. The staff at your local Ra-
dioShack store often can help you locate a club. 
If you do not hear anyone talking about a local club as you listen
to local transmissions, write to the American Radio Relay League
(ARRL) at the following address to find out how to contact a local
affiliate. The ARRL is the national organization representing am-
ateur radio in the United States. The league has more than
150,000 members. Most are ham operators, or members in the
process of obtaining their license. 
The American Radio Relay League
225 Main Street
Newington, CT 06111
http://www.arrl.org 
						

							8
Start studying for the license exams. Do not be intimidated by the
word “study,” because most people can go from knowing abso-
lutely nothing about amateur radio to passing the Novice and
Technician written exams in less than a month. 
The exams test your knowledge of basic radio regulations and el-
ementary radio theory. Many clubs hold license classes which
can be a fun and easy way to learn about amateur radio. There
are good books, cassette tapes, computer programs, and many
other study aids available. Your local RadioShack store sells 
FCC
License Preparation
 study guides for amateur radio operator li-
censes. While you are no longer required to learn Morse code for
a Technician Class license, we encourage you to learn it anyway
so you can advance to higher levels of operating privileges.
There is no fee to take the Novice exam. As soon as you pass the
Novice exam, you can immediately take the Technician exam.
There is a small fee required for taking the Technician exam. All
license level tests are administered by a three-member Volunteer
Examiner Team. Contact the ARRL for a schedule of exam op-
portunities in your area.
The Technician Class license lets you use this transceiver to
communicate directly with other operators, and use repeaters for
distant communication.
Amateur radio is a great hobby that has enriched the lives of mil-
lions of people all over the world. The ARRL would be glad to hear
from you if you need more information or would like to join! 
						

							9
PREPARATION
ATTACHING THE
MICROPHONE HOLDER
Follow these steps to attach the
microphone holder to your vehicle.
1. Using the holder as a tem-
plate, mark the position for the
mounting screw holes at the
desired location.
2. At each marked position, drill
a hole slightly smaller than the
supplied mounting screw.
Caution: Be careful not to drill
into anything behind the
mounting surface. 
3. Use a Phillips screwdriver to attach the holder to the mount-
ing location with the supplied small self-tapping sheet metal
screws and lock-washers.
MOUNTING THE TRANSCEIVER
The most common mounting location for this transceiver is under
a vehicle’s dashboard. However, if you plan to use the transceiver
as a base station, you can place it on a desk, shelf, or table (see
“Using the Transceiver as a Base Station” on Page 13).
If you are mounting the transceiver in a vehicle, choose a loca-
tion where:
• you can easily reach the transceiver
• wires and cables are clear of the vehicle’s pedals or other
moving parts
• the transceiver is not directly in front of heating vents
• all wires and cables can reach their connection points 
						

							10
Caution: If you use the transceiver in a vehicle, mount it securely
to avoid damage to the transceiver or vehicle, or injury to anyone
in the vehicle during sudden starts or stops.
Follow these steps to mount the transceiver.
1. Using the mounting bracket as a template, mark the posi-
tions for the screw holes on the mounting surface,
2. In each marked location, drill a hole slightly smaller than the
supplied self-tapping screws.
Caution: Be care not to drill into objects behind the mount-
ing surface.
3. Using a Phillips screwdriver, attach the mounting bracket to
the mounting surface with the supplied mounting screws
and flat washers.
4. Attach the transceiver to the mounting bracket using the
supplied rubber washers and mounting knobs.
V
O
L
O
P
S
Q