Radio Shack Stereo Receiver HTX 400 User Guide

Cat. No. 19-1104  
OWNER’S MANUAL  
Please read before using this equipment.  
HTX-400  
Mini Handheld 70-Centimeter FM  
Amateur Transceiver  
 
Paging Tones— you can set the radio to play a short, selectable  
paging tone when it transmits, and sound the same tone when it  
receives a signal.  
Signal Strength Indicator — a graduated bar shows the relative  
strength of the received signal.  
Time-Out Timer — lets you set a maximum transmission time in-  
terval from 0 to 161/2 minutes in 10-second increments.  
Busy Channel Lock Out — prevents transmitting while the se-  
lected channel is receiving a signal.  
TX Delay — reduces squelch tail when communicating using  
CTCSS.  
Scan Delay — delays the restart of scanning when the radio  
locks onto a channel.  
Earphone Jack and External Microphone Jack — let you con-  
nect an optional earphone, external microphone, or combination  
headset, for more flexible operation.  
External Power Jack — lets you use an external power source  
for maximum output.  
30 Memory Locations — let you store up to 30 frequencies and  
other settings.  
Back Light — makes your transceiver easy to operate in low-  
light situations.  
Key Lock — lets you lock the transceiver’s keys to prevent acci-  
dentally changing settings.  
We recommend you record your transceiver’s serial number  
here. The number is on the transceiver’s back panel.  
Serial Number ____________________________  
3
 
MANUAL CONVENTIONS  
Your transceiver’s buttons perform multiple functions. The abbre-  
viation or symbol for a function is printed on, below, or above  
each button.  
To activate certain transceiver features, you must press FUNC  
(function) and another button at the same time. Those key com-  
bination instructions are printed as the first button name, +, then  
the second button name. For example, FUNC+LOCK means  
hold down FUNC while you press LOCK.  
Button names are printed in small, bold, capital letters such as  
BEEP or SC. Words, symbols, and numbers that appear on the  
display are printed using a distinctive typeface, such as  
446.100 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.  
4
 
CONTENTS  
Introduction to Amateur Radio ............................................. 7  
Preparation ............................................................................. 9  
Power Sources .................................................................. 9  
Using Internal Batteries ............................................. 9  
Testing Internal Batteries ......................................... 10  
Using AC Power .............................................................. 11  
Using Ni-Cd or Ni-MH Battery Power .............................. 11  
Using Vehicle Battery Power ........................................... 12  
Connecting the Antenna ................................................. 13  
Attaching the Belt Clip .................................................... 13  
Attaching the Wrist Strap ................................................ 14  
Connecting a Microphone/Speaker ................................. 14  
Using the Menus .................................................................. 16  
Using the HTX-400’s Menus ........................................... 16  
A Quick Look at the Controls .............................................. 19  
A Quick Look at the Display ................................................ 22  
Operation .............................................................................. 23  
Turning on the HTX-400 .................................................. 23  
Selecting Frequencies (Direct Tuning) ............................ 23  
Receiving Transmissions ................................................. 24  
Temporarily Opening Squelch ......................................... 24  
Transmitting ..................................................................... 25  
Understanding Repeaters ................................................... 26  
Setting the Repeater Offset Frequency .......................... 27  
Turning Duplex Operation On and Off ............................. 27  
Setting the Repeater Offset Direction ............................. 28  
Reversing the Transmit and Receive Frequencies .......... 28  
Memory Operation ............................................................... 29  
Storing a Transmit/Receive Frequency ........................... 29  
Recalling Memories ........................................................ 30  
Clearing A Single Memory .............................................. 30  
Using the Calling-Frequency Memory ............................. 31  
5
 
Scanning Operation ............................................................. 32  
Scanning for Active Frequencies ..................................... 32  
Using Scan Delay ..................................................... 32  
Scanning Standard Memory Locations ........................... 32  
Setting A Memory Location to Always Skip  
During Scanning ...................................................... 33  
Temporarily Locking Out (Skipping) Locations  
During Memory Scanning ........................................ 34  
Continuous Tone Coded Squelch System Features ......... 35  
Tone Paging ..................................................................... 37  
Sending Paging Tones ..................................................... 37  
Other Special features ......................................................... 38  
Changing the Transmit Frequency Range ....................... 38  
Locking the Keypad ......................................................... 38  
Lighting the Display ......................................................... 38  
Turning the Key Tone On and Off .................................... 39  
Checking the Current Memory Settings .......................... 39  
Setting the Frequency Step ............................................. 39  
Power Save ..................................................................... 40  
Time-Out Timer ............................................................... 40  
Reducing Squelch Tail ..................................................... 41  
Busy Channel Lockout .................................................... 41  
Troubleshooting .................................................................... 42  
Care and Maintenance ......................................................... 43  
Using the Keypad Diagnostic .......................................... 44  
Resetting the HTX-400 .................................................... 44  
Specifications ....................................................................... 45  
6
 
INTRODUCTION TO AMATEUR RADIO  
Your 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. Your  
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  
7
 
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  
FCC  
other study aids available. Your local RadioShack store sells  
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 the HTX-400 to com-  
municate directly with other operators, and use repeaters for dis-  
tant 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!  
8
 
PREPARATION  
POWER SOURCES  
You can operate your transceiver from any of three power sourc-  
es:  
• internal batteries  
• AC power (using an optional power supply and DC adapter)  
• vehicle battery power (using an optional DC adapter)  
Using Internal Batteries  
Your transceiver can use two AA batteries (not supplied) for pow-  
er. For the best performance and longest life, we recommend Ra-  
dioShack alkaline batteries.  
Cautions:  
• Use only fresh batteries of the required size and recom-  
mended type.  
• Do not mix old and new batteries, different types of batteries  
(standard, alkaline, or rechargeable), or rechargeable bat-  
teries of different capacities.  
Follow these steps to install batteries.  
LOCK Tab (on bottom)  
1. Move the LOCK tab in the opposite direction of the arrow  
marked on the bottom of the transceiver.  
9
 
2. Press down and slide the battery compartment cover in the  
direction of the arrow marked on the cover.  
3. Put the batteries into the compartment and on top of the  
attached ribbon, according to the polarity symbols (+ and –)  
marked inside the compartment.  
4. Replace the cover and slide the  
cover.  
tab to secure the  
LOCK  
Testing Internal Batteries  
BAT  
When you turn on the HTX-400,  
uated bar (the signal strentgth meter) next to  
battery strength. If the batteries are weak, the graduated bar  
shows less than 4 boxes. The battery symbol ( ) constantly in-  
appears briefly and the grad-  
BAT  
indicates the  
dicates the battery strength. When only one or two bars appear  
inside the battery strength indicator, replace both batteries as  
soon as possible.  
Warning: Dispose of old batteries promptly and properly. Do not  
burn or bury them.  
Caution: If you do not plan to use the transceiver with batteries  
for a two week period, remove the batteries. Batteries can leak  
chemicals that can destroy electronic parts.  
10  
 
USING AC POWER  
You can operate the HTX-400 from AC power using a regulated  
power supply capable of supplying 13.8 VDC at least 1A and a  
vehicle power adapter (see “Using Vehicle Battery Power” on  
Page 12). The supply should also have an accessory power  
socket into which the DC-to-DC power adapter fits. If your power  
supply does not have an accessory power socket, you can either  
wire the power cord directly to your power supply or add an ac-  
cessory power socket to the supply. Suitable connectors, power  
supplies, power cords, and sockets are available at your local  
RadioShack store.  
The following illustration shows how to connect a typical power  
supply, a DC-to-DC power adapter, and the HTX-400.  
USING NI-CD OR NI-MH BATTERY  
POWER  
You can use either Ni-Cd or Ni-MH batteries to power your HTX-  
400; however, you cannot recharge these batteries while they are  
inside the HTX-400. You can use a separate external charger for  
recharging the batteries outside the radio. Your local RadioShack  
store carries a selection of suitable batteries and chargers.  
Note: As these batteries provide less voltage than that typically  
supplied by alkaline batteries, expect less transmitting output  
power when you use the HTX-400 with Ni-Cd or Ni-MH battery  
power.  
11  
 
USING VEHICLE BATTERY POWER  
You can power the HTX-400 from a vehicle’s 12V power source  
(such as cigarette-lighter socket) using an 9-volt, 900 mA DC-to-  
DC power adapter and a size I Adaptaplug® (neither supplied)  
with TIP set to +. Both are available at your local RadioShack  
store.  
Cautions:  
You must use a power source that supplies 9V DC  
and delivers at least 900 mA. Its center tip must  
!
be set to positive and its plug must fit the HTX-  
400's DC 9V jack. Using an adapter that does not meet  
these specifications could damage the HTX-400 or the  
adapter.  
• Always connect the DC adapter to the HTX-400 before you  
connect it to the power source. When you finish, disconnect  
the adapter from the power source before you disconnect it  
from the HTX-400.  
Follow these steps to operate the HTX-400 from a vehicle’s bat-  
tery power.  
1. Insert the Adaptaplug into the HTX-400’s DC 9V jack.  
2. Plug the other end of the adapter into the cigarette-lighter  
socket in the vehicle.  
12  
 
CONNECTING THE ANTENNA  
Place the threaded base socket of the supplied antenna over the  
antenna connector on top of the transceiver and turn the antenna  
. Turn it clockwise to remove it.  
clockwise to tighten it  
U
Caution: Do not over-tighten the antenna  
Note: You can connect an external antenna to the HTX-400 using  
an SMA-to-PL-259 adapter. This adapter, as well as suitable an-  
tennas, are available through your local RadioShack store.  
ATTACHING THE BELT CLIP  
Use a Phillips screwdriver and the two supplied screws to attach  
the supplied belt clip to your transceiver. Do not overtighten the  
screws.  
13  
 
ATTACHING THE WRIST STRAP  
To attach the supplied wrist strap to the top of the belt clip, thread  
the strap’s small loop through the opening in the top of the clip.  
Then insert the longer loop through the smaller loop and pull on  
the strap until the loop is tight.  
CONNECTING A MICROPHONE/  
SPEAKER  
You can connect an external communications headset (con-  
sisting of a microphone and speaker) to the transceiver so you  
can use it privately. Lift the hinged, rubber dust cover from the  
MIC and SPK jacks on the top of the transceiver, then insert  
the plug of an optional voice activated headset with micro-  
phone, or an optional communication headset, into the jacks.  
14  
 
Caution: Use only microphone and speaker accessories that do  
not share a common ground for the speaker and the microphone.  
Doing otherwise might damage the transceiver.  
Note: Inserting a headset’s plug automatically disconnects the in-  
ternal speaker.  
You can also connect an optional mono earphone to the SPK  
jack. This lets you use the transceiver’s push-to-talk button to  
transmit as usual. Your local RadioShack store carries a wide se-  
lection of suitable communications headsets, earphones, and  
separate components.  
The following schematic diagram shows the typical wiring for a  
suitable external mic and speaker.  
External Speaker  
Speaker-  
Plug  
Barrel  
+
Tip  
External Microphone  
MIC Plug  
Barrel  
22k  
+
Tip  
PTT  
15  
 
USING THE MENUS  
USING THE HTX-400’S MENUS  
The HTX-400 provides two menus to access its features, the  
Main Menu and the Tone Set Menu. To see details about each  
operation, refer to the page number in the following chart.  
To access the Main Menu, hold down FUNC while turning on the  
HTX-400. (The CS option appears). Hold down  
then re-  
FUNC  
peatedly press Wor V to step through the other options. Release  
and press V or W to change an option’s setting.  
FUNC  
Setting  
Main Menu  
Options  
( ) = default  
setting  
Description  
Page  
CS  
Frequency  
Step  
.0050  
.0100  
(.0125) .0150  
(MHz),  
,
,
Sets the increment  
for scanning the  
band.  
39  
,
.0200 .0250  
,
,
.0500 1.000  
,
bCLO  
Busy Chan-  
nel Lockout  
(Off)  
On  
Prevents transmit-  
ting while receiving  
a signal.  
41  
41  
32  
t.dY  
Transmit  
Delay Time  
Off  
(On)  
Prevents  
squelch tail.  
Sd  
1 to 30 seconds  
(5)  
Sets the scanning  
restart time.  
Scan Delay  
Time  
16  
 
Setting  
( ) = default  
setting  
Main Menu  
Options  
Description  
Page  
tot  
(Off)  
Limits transmit time.  
40  
Time out  
Timer  
On 10-990 seconds  
PS  
(Off)  
On  
Cycles power  
40  
PS  
flashes) to the  
Power Save  
(
receiver section to  
conserve batteries.  
The circuit remains  
off then turns on  
briefly to check for  
an incoming signal.  
r
0.00 8.00  
MHz  
in 50kHz steps.  
(5.00)  
Sets the offset in 50  
kHz steps between  
the repeater’s trans-  
mit and receive fre-  
quencies.  
27  
Repeater  
Offset  
17  
 
The Tone Set Menu lets you set features that relate to sound and  
the CTCSS tones. To access these settings, turn on the HTX-400  
then  
FUNC  
T.SET  
and press . (The tone option ap-  
hold down  
FUNC  
V
W
V
W
pears.) Press  
+
or to select the option, then or to  
change the setting.  
Tone Set  
Setting  
Option  
( ) = default setting  
Description  
Page  
tone  
Subaudible  
Tone  
(Off)  
On  
Lets the HTX-400  
transmit and  
receive the Sub-  
audible Tone  
35  
(CTCSS) fre-  
quencies so you  
can listen only to  
other units with  
the same tone.  
rC  
Receive  
Tone  
See the table  
on Page 36.  
(67.0)  
Lets you select  
one of 47 different  
receiving sub-  
35  
audible tones or  
turn the feature  
off  
.
tC  
See the table  
on Page 36.  
(67.0)  
Lets you select  
one of 47  
different subaudi-  
ble tones or turn  
35  
37  
Transmit  
Tone  
the feature off  
.
MEL  
Tone Paging  
(1), 2, 3, 4, 5  
Lets you select a  
tone to receive or  
transmit.  
18  
 
A QUICK LOOK AT THE CONTROLS  
Most of the controls of the HTX-400 have multiple functions. Use  
the following chart to review the function of each control.  
VOL/OFF  
Microphone  
SQ  
PTT  
U
Speaker  
Use with the  
Key/Control  
VOL/OFF  
Use it to:  
FUNC + Key to:  
Turn the radio on/off.  
Adjust the volume.  
Access the Main  
Menu.  
SQ  
Set the squelch level  
to block weak signals.  
N/A  
(
)
Change (increase) the  
frequency by the value  
set for CS (see the first  
menu option on Page  
16).  
Directly changes  
the frequency, one  
digit at a time.  
Repeatedly press  
V to access each  
digit of the dis-  
played frequency.  
19  
 
Use with the  
Key/Control  
(T.SET)  
Use it to:  
FUNC + Key to:  
Change (decrease)  
the  
frequency by the value  
set for CS (see the first  
menu option on Page  
16).  
Accesses the Tone  
Set Option menu  
and settings.  
MO (REV)  
Press to override  
Reverse the  
squelch. Press and  
hold to cycle through  
repeater offset.  
rC tC r  
CS  
set-  
,
,
, and  
tings.  
Turn on the display’s  
backlight for 4 sec-  
onds.  
Enable/disable the  
key tone.  
appears when the  
key tone is enabled.  
(BEEP)  
MR (MW)  
Enter memory setting  
mode. MRand the last  
used memory location  
appear.  
In memory mode,  
starts the display  
flashing. Then use  
or  
to  
access a frequency  
to store in a mem-  
ory location.  
SC (RPT)  
Starts and stops scan-  
ning. Hold down and  
power on to access  
expanded band cover-  
age  
Set the radio to  
simplex or duplex  
mode when in VCO  
mode. Set the  
repeater offset for a  
memory location  
when in memory  
mode.  
(420–450 MHz).  
20  
 
Use with the  
Key/Control  
C (LOCK)  
Use it to:  
FUNC + Key to:  
Press once to display  
and switch to the cur-  
rent call frequency.  
Hold down to change  
the call frequency and  
associated parame-  
ters, such as repeater  
offset and CTCSS  
tones.  
Lock the control  
(except PTT, MO,  
, VOL, and SQ).  
Press again to  
unlock the controls.  
PTT  
(Push To Talk)  
Hold down to trans-  
mit. Press to store the  
settings.  
Swap the input and  
output frequencies  
for repeater opera-  
tions.  
21  
 
A QUICK LOOK AT THE DISPLAY  
17  
16  
15 14 13 12  
1
2
3
4
5
6
7
8
9 10 11  
1. F: appears when the FUNC key is pressed.  
2. TX: appears when the radio is transmitting.  
3. BUSY: appears when the radio receives a signal.  
4. CALL: appears when tone squelch is on and the radio receives a  
matching tone.  
5.  
: indicates the battery strength.  
6. S-RF (Signal/RF Indicator): shows the level of an incoming signal.  
When transmitting, shows the relative output signal strength.  
7. BAT: appears when you turn on the radio — the signal strength  
meter then indicates the battery strength.  
8.  
: the stronger the signal, the more boxes appear.  
Bars show remaining battery power when MO and PTT switch are  
held down at the same time.  
9. Alpha-Numeric Display: shows frequency and messages.  
10. Memory Location: shows the memory channel in use.  
11. MR (Memory Channel indicator): for use or for programming.  
12.  
13.  
14.  
: paging tone active.  
: key tone enabled.  
: keypad control disabled to prevent accidentally  
changing a setting.  
15. PS: appears when power save is enabled.  
16. TSQ: appears when Tone Squelch (CTCSS) is enabled.  
ã
17. : appears to indicate a positive repeater offset. indicates a nega-  
tive repeater offset.  
22  
 
OPERATION  
TURNING ON THE HTX-400  
To turn on the HTX-400, rotate  
clockwise until it clicks.  
VOL/OFF  
The HTX-400 sounds a brief melody if the key tone feature is en-  
abled. Then HELLOappears for about 2 seconds and the last  
used frequency appears.  
SELECTING FREQUENCIES  
(DIRECT TUNING)  
You tune to the desired frequencies in the VFO (variable frequen-  
cy oscillator) mode. You can either step to a specific frequency or  
directly select the frequency.  
To step to a frequency, repeatedly press or hold down  
until the display shows the desired frequency.  
or  
Note: The HTX-400 steps up or down in increments which you  
set using the Frequency Step menu option. (See “Setting the Fre-  
quency Step” on Page 39).  
To directly enter a frequency, press FUNC+ (the second digit  
from the left flashes), then press  
or  
to change the number.  
Press FUNC+ again to select the next digit. Repeat this to select  
each number of the desired frequency, then press PTT to store  
the selection.  
Note: The HTX-400 is preset to receive frequencies between 420  
and 470 MHz, and transmit between 430 and 450 MHz. To ex-  
pand the frequency coverage, see “Changing the Transmit Fre-  
quency Range” on Page 38.  
23  
 
RECEIVING TRANSMISSIONS  
Follow these steps to receive standard transmissions.  
1. With the radio on, rotate  
counterclockwise until you hear  
SQ  
a hissing sound. Then slowly rotate SQ clockwise just until  
the noise stops.  
Notes:  
BUSY appears when the HTX-400 receives a standard  
transmission or if the squelch is open. If the transmission  
uses CTCSS tones, CALLalso appears.  
Volume, power, and squelch are combined in one control.  
The inner control is VOL (volume) and power on/off, while  
the outer control is SQ (squelch).  
• If the HTX-400 picks up unwanted, weak transmissions,  
rotate SQ clockwise to prevent the squelch from opening  
for these transmissions. If you want to hear weak trans-  
missions, rotate SQ counterclockwise. When you do this,  
you might hear hissing between transmissions.  
2. Set VOL/OFF to a comfortable listening level.  
TEMPORARILY OPENING SQUELCH  
If you use the Tone Squelch (CTCSS) feature, you might not hear  
a trans  
o temporarily open the  
mission on the current frequency. T  
squelch so you can hear all transmissions on the frequency, hold  
down MO. To resume normal operation, release MO.  
24  
 
TRANSMITTING  
There are two basic types of communication possible with this  
transceiver: radio-direct-to-radio (simplex) or radio-to repeater-to  
radio (duplex). Simplex operation uses the same frequency to  
send and receive. Duplex operation uses one frequency to trans-  
mit and another to receive. For more information about duplex,  
see “Understanding Repeaters” on Page 26.  
Caution: It is illegal to transmit if you do not have at least a Tech-  
nician Class license issued by the FCC.  
Follow these steps to transmit.  
1. Select the desired frequency using manual or direct entry.  
2. Hold the HTX-400 about 3 inches from your mouth.  
3. Hold down PTT, then speak slowly and clearly into the micro-  
phone. TXappears while you transmit.  
Note: If you try to transmit outside the transmit frequency  
range, inhibitbriefly appears.  
4. Release PTT when you finish transmitting.  
25  
 
UNDERSTANDING REPEATERS  
Operation through a repeater, where you transmit on one fre-  
duplex  
quency and receive on another, is called  
ation direct to another station, where you transmit and receive on  
simplex  
operation. Oper-  
the same frequency, is called  
operation.  
A repeater is a station that receives a signal on one frequency  
input  
(the  
frequency) and then retransmits that signal on a differ-  
output  
ent frequency (the  
frequency). Repeater antennas are typ-  
ically located at the tops of tall buildings or on antenna towers, so  
a relatively low-power signal can reach the repeater. The repeat-  
er retransmits the signal at a higher power. This gives your trans-  
ceiver the ability to communicate over a much greater range.  
To use a repeater, you must know the repeater’s input and output  
frequencies. Repeaters are usually identified by their output fre-  
quency. Thus, a repeater that has an output frequency of 442.200  
is referred to as “the 442.2 repeater.” To determine the input fre-  
offset  
offset direction  
quency, you must know the frequency  
the 70 cm-meter band) and the  
(typically 5 MHz for  
(+ if you add 5  
MHz to the output, or – if you subtract 5 MHz from the output).  
Whether the offset is positive or negative depends on:  
• which part of the band the repeater operates on  
• local convention  
• proximity of repeaters using the same two frequencies  
The  
To determine the offset and the direction, obtain a copy of  
ARRL Repeater Handbook  
(available from your local Ra-  
dioShack store or directly from the ARRL) which lists the loca-  
tions of repeaters as well as their frequency and offset  
information.  
A
above the displayed frequency indicates a positive offset,  
+
while a above the frequency indicates a negative offset. If nei-  
ther  
or appears, the HTX-400 is set for simplex operation.  
n
+
26  
 
SETTING THE REPEATER OFFSET  
FREQUENCY  
The HTX-400’s default repeater offset is 5 MHz, which appears  
as 5.00  
). Follow these steps to change the offset.  
(MHz  
Note: This setting only affects the VFO mode. If you saved a fre-  
quency offset in a memory, that setting is not affected.  
1. With power off, hold down FUNC and turn on the HTX-400,  
2. Hold down FUNC and repeatedly press  
until r and  
the  
appear. 5.00appears if no offset is currently  
current offset  
set.  
3. Repeatedly press  
or  
until the desired offset appears.  
You can set an offset between 0 and 8 MHz in 50kHz steps.  
4. Press PTT to store the setting and exit the menu.  
TURNING DUPLEX  
OPERATION ON AND OFF  
To turn on duplex (repeater use) operation for the VFO mode,  
press FUNC + SC (RPT). Provided the current repeater offset val-  
ue is not 0.00, the current offset indicator (+above or below)  
appears above the displayed frequency. Press FUNC + SC (RPT)  
again to turn it off.  
27  
 
SETTING THE REPEATER OFFSET  
DIRECTION  
1. Set an offset frequency other than 0.00.  
2. Press FUNC + SC (RPT) to see the current offset direction (+  
above or below).  
3. Press FUNC + MO (REV) to change the repeater offset direc-  
tion.  
MR  
Note: To save this setting in a memory location,  
must be  
flashing before you store the settings (see “Using the Calling-Fre-  
quency Memory” on Page 31 and “Storing a Transmit/Receive  
Frequency” on Page 29). Otherwise, the setting reverts to its  
saved value the next time you turn on the HTX-400.  
REVERSING THE TRANSMIT AND  
RECEIVE FREQUENCIES  
To swap the input and output frequencies, press  
. For  
FUNC+PTT  
example, if you have set the radio to repeater operation on  
442.200 with a positive offset of 5 MHz, the radio would normally  
receive on 442.200 and transmit on 447.200 MHz. After you  
press FUNC+PTT, the radio will receive on 447.200 and transmit  
on 442.200.  
This feature is useful if you want to determine whether you are  
close enough to another station to communicate on a simplex fre-  
quency. While the other station is transmitting, reverse the fre-  
quencies. If you can still hear the other station, you are hearing  
their signal directly and you do not need to use the repeater.  
28  
 
MEMORY OPERATION  
Your HTX-400 has 30 standard memory locations that you can  
use to store frequencies for quick access. For each memory loca-  
tion, you can also store other settings such as the repeater offset,  
CTCSS tones, and frequencies to pass or lock out during scan-  
ning.  
STORING A TRANSMIT/RECEIVE  
FREQUENCY  
MR  
1. Press MR.  
and the last used memory location appear.  
or to select the desired memory  
2. Repeatedly press  
location. ------ appears if the memory location is empty.  
MR  
. The selected memory location and  
FUNC MR  
3. Press  
flash.  
+
4. Select the desired frequency by repeatedly pressing  
or , or use direct frequency entry to select a frequency.  
5. To enter a frequency offset for repeater operation, press  
+
. The HTX-400 displays the current offset for the  
FUNC SC  
calling frequency. Then press  
or  
to select the desired  
offset. Press PTT to store your setting.  
6. Press FUNC + REV to select the offset direction (+ or –). To  
remove an offset for simplex operation, set the repeater off-  
set to 0.00.  
7. If desired, set the tone squelch settings (see “Continuous  
Tone Coded Squelch System Features” on Page 35).  
8. Press  
to store all settings, then press  
PTT  
MR  
to exit the  
memory mode.  
29  
 
RECALLING MEMORIES  
MR  
appears. Then  
To recall saved memory settings, press  
so  
MR  
press  
or  
to select the desired memory location.  
Press  
again to return to the VFO mode, (See “Selecting Fre-  
MR  
quencies (Direct Tuning)” on Page 23.)  
CLEARING A SINGLE MEMORY  
Follow these steps to clear any single memory location.  
MR  
and the last used memory location appear.  
1. Press  
.
MR  
2. Repeatedly press  
location.  
or  
to select the desired memory  
MR  
. The selected memory location and  
FUNC MR  
3. Press  
flash.  
+
4. Hold down FUNC for several seconds. The memory location  
clears and ------ appears to confirm that the location is  
empty.  
5. Press MR to exit the memory mode.  
Note: To clear all memory locations, see “Resetting the HTX-  
400” on Page 44.  
30  
 
USING THE CALLING-FREQUENCY  
MEMORY  
The calling-frequency memory location lets you quickly jump to  
a specific frequency at any time. The default calling frequency  
is 446.0000 MHz. You can store a different frequency into mem-  
ory as well as other settings associated with that frequency,  
such as the repeater offset and CTCSS tone.  
1. Press C to display the current calling frequency.  
MR  
2. To change the frequency, hold down C until  
and C  
flash.  
3. Select a frequency. See “Selecting Frequencies (Direct  
Tuning)” on Page 23.  
4. Press to store the selected frequency in memory.  
C
5. To enter a frequency offset for repeater operation, press  
. The HTX-400 displays the current offset for the  
FUNC+SC  
calling frequency. To select a new offset value, press  
or  
. Select 0.00 Hz if you want to remove the offset. To  
store the setting, press PTT.  
6. To select the offset direction (+ or –), press  
To  
FUNC + REV.  
remove an offset for simplex operation, set the repeater  
offset to 0.00  
.
MR  
Note: While  
and  
Cappear, you can program other set-  
tings such as CTCSS tones (see “Continuous Tone Coded  
Squelch System Features” on Page 35.)  
To enable the calling frequency, press C at any time. The trans-  
ceiver immediately tunes to that frequency with the settings you  
programmed. To exit the calling frequency mode, press C again.  
31  
 
SCANNING OPERATION  
SCANNING FOR ACTIVE FREQUENCIES  
1. To search for activity on a frequency, press  
. The trans-  
SC  
ceiver begins to scan up or down the full frequency range,  
and it stops on each active frequency for the duration set by  
the scan delay option (see “Using Scan Delay” on Page 32).  
2. To change the scanning direction, press  
or  
.
3. To stop on a frequency or to stop scanning completely,  
press SC again.  
Using Scan Delay  
that signal  
If the HTX-400 stops on a signal during scanning, then  
stops, the scan delay feature delays the continuation of scanning  
to allow time for the signal to restart. Access the Main Menu (see  
“Using the HTX-400’s Menus” on Page 16) to set the value. With  
Sd  
press  
or  
to select the  
and the current delay time shown,  
new delay time (between 1 and 30 seconds).  
SCANNING STANDARD MEMORY  
LOCATIONS  
MR  
1. Press MR  
appears), then press SC. The transceiver  
(so  
scans all locations except empty locations and the ones you  
programmed to be passed during scanning.  
2. To change the scanning direction, press  
or  
.
3. To stop scanning, press SC again.  
32  
 
Setting A Memory Location to Always Skip  
During Scanning  
The HTX-400 is preset to include all memory locations (except  
empty locations) during memory scanning . Follow these steps  
to set the transceiver to have it always skip (or resume scan-  
ning) a specific location during scanning.  
MR  
1. Press MR.  
and the last used memory location appear.  
2. Repeatedly press  
location.  
or  
to select the desired memory  
MR  
3. Press FUNC+MR. The selected memory location and  
flash.  
4. To set the HTX-400 to skip the memory location, press SC,  
then press  
or  
so SCSPON(scan skip) appears.  
To include the displayed location during scanning, press  
or so SCSPoFappears.  
5. When you finish, press SC again, then press PTT to store  
the setting.  
33  
 
Temporarily Locking Out (Skipping) Locations  
During Memory Scanning  
You can set the transceiver to lock out a location while scanning  
the frequencies stored in memory.  
When the transceiver stops at a memory location you want to  
FUNC PASS  
briefly appears and the transceiver con-  
skip, press  
.
tinues to scan, locking out (skipping) that location from then on.  
Repeat this for each location you want to skip.  
To cancel the settings and have the HTX-400 include the skipped  
frequencies once again, turn the radio off then on again.  
You cannot lock out all memory locations. One location is  
Note:  
always active. If you lock out all but two active locations and then  
lock out one more, EMPTYbriefly appears and scanning stops.  
34  
 
CONTINUOUS TONE CODED  
SQUELCH SYSTEM FEATURES  
Your HTX-400 can transmit and receive a low-level, selectable  
subaudible tone at the same time as it transmits (TX) or receives  
(RX) a regular signal. This special tone lets you listen only to oth-  
er radios set to the same tone frequency when you use the HTX-  
400 in simplex operation. It also lets you match your radio to the  
subaudible tone frequency used by a local repeater.  
To enable the TX and RX tones for the HTX-400, follow these  
steps.  
1. Press FUNC+ . The current tone setting appears (tONEoF  
or tone on).  
2. Press  
or  
to turn on the option . tONE on appears.  
3. To set a receive (RX) tone, press FUNC+ . rC appears.  
Then press  
or  
to select a tone frequency from the list  
on Page 36.  
For this example, 67.0 Hz was selected for  
both the transmit and receive frequencies.  
4. To set a transmit (TX) tone, press FUNC+ . tC appears.  
Then press  
on Page 36.  
or  
to select a tone frequency from the list  
5. Press PTT to store all the settings.  
35  
 
To select and store a CTCSS subaudible tone in a memory loca-  
MR  
MR.  
tion, press  
and the last used memory location appear.  
(In the examples shown on the preceding page, memory location  
2 is used.) Then follow the preceding Steps 1–5.  
Subaudible Tone Frequencies (Hz)  
67.0  
69.3  
71.9  
74.4  
77.0  
79.7  
82.5  
85.4  
88.5  
91.5  
94.8  
97.4  
100.0  
103.5  
107.2  
110.9  
114.8  
118.8  
123.0  
127.3  
131.8  
136.5  
141.3  
146.2  
151.4  
156.7  
159.8  
162.2  
167.9  
173.8  
179.9  
183.5  
186.2  
189.9  
192.8  
196.6  
199.5  
203.5  
206.5  
210.7  
218.1  
225.7  
229.1  
233.6  
241.8  
250.3  
254.1  
Off  
36  
 
TONE PAGING  
You can set the HTX-400 to sound an alert tone when it receives  
a transmission that includes the currently set subaudible receive-  
tone (or any transmission, if the receive-tone or the tone feature  
is set to off). Turn off the radio, then press  
HTX-400 on again. appears.  
while you turn the  
The first time the HTX-400 receives a transmission that matches  
the current CTCSS settings, it sounds the selected alert tone,  
then turns off the tone paging feature. To turn the feature back on,  
turn the power off then on again while holding down  
.
Follow these steps to change the alert tone.  
1. Select the VFO mode. (See “Selecting Frequencies (Direct  
Tuning)” on Page 23.)  
2. Hold down FUNC and press  
(T.SET) four times. MELand a  
number from 1to 5appear. Release FUNC.  
3. Repeatedly press either  
or  
to step through the five dif-  
ferent tones. If key tone is enabled, each tone sounds as  
you select its number.  
4. Press PTT to store your selection and exit the menu.  
SENDING PAGING TONES  
To transmit the selected paging tone, press  
while pressing  
PTT  
.
37  
 
OTHER SPECIAL FEATURES  
CHANGING THE TRANSMIT FREQUENCY  
RANGE  
You can change the standard transmit frequency range from  
430–450 MHz to an extended range of 420–450 MHz.  
To set the transceiver to its extended range, turn off the transceiv-  
er, then hold down SC and turn on the transceiver again.  
To return to the standard frequency range, turn off the transceiv-  
er, then hold down  
and turn it on again.  
SC  
LOCKING THE KEYPAD  
To lock the transceiver’s keypad so you do not accidentally  
FUNC LOCK  
change a setting, press  
+
.
appears. This locks all  
PTT  
VOL  
SQ  
, and .  
buttons except  
,
,
FUNC LOCK  
To unlock the keypad, press  
+
again.  
LIGHTING THE DISPLAY  
Press  
to turn on the display’s backlight for about 4 seconds. If  
you press any key while the light is on, the light remains on for  
about 4 seconds more. Hold down for at least 1 second to have  
the light remain on until you press  
again.  
38  
 
TURNING THE KEY TONE ON AND OFF  
The transceiver is preset to sound a beep each time you press a  
FUNC  
BEEP)  
.
(
key. To turn off the beep, press  
To restore the key tone, press  
+
+
(
disappears.  
BEEP  
) again.  
FUNC  
Note: If the key tone feature is disabled, the power-on tone does  
not sound.  
CHECKING THE CURRENT MEMORY  
SETTINGS  
If you hold down MO (REV) for longer than 1 second, the squelch  
opens and the set values for receive tone (rTon/off), transmit  
tone (tton/off), scan skip condition (SCSP)(if any), repeater  
offset (r), and frequency step (CS) appear.  
Release MO (REV) to turn on the squelch again.  
SETTING THE FREQUENCY STEP  
To change the frequency increment used during scanning and  
stepping to a frequency, use the Main Menu to access the CS op-  
tion setting (see “Using the HTX-400’s Menus” on Page 16). Then  
repeatedly press  
or  
until you reach the desired setting. You  
can change the frequency step to 5 kHz, 10 kHz, 12.5 kHz, 15  
kHz, 20 kHz, 25 kHz, 50 kHz, or 1 MHz. (The example shown  
here is 25 kHz.)  
39  
 
POWER SAVE  
The power save feature lets the radio conserve battery power by  
turning off power to the receiver section and periodically turning  
it on to check for a transmission. Use the Main Menu to set the  
power save option (see  
“Using the HTX-400’s Menus” on Page  
With PSand the current status (onor oFF) displayed, press  
16).  
or  
to turn this feature on or off.  
TIME-OUT TIMER  
When you communicate using repeaters, keep your transmis-  
sions as brief as possible. Most repeaters have built-in timers that  
limit single transmissions to 3 minutes or less. You can set the  
transceiver to stop transmitting and sound a beep if you exceed  
a set time limit with a single transmission.  
Use the Main Menu (see “Using the HTX-400’s Menus” on Page  
16) to set a value for the time-out timer. With totand the current  
setting displayed, press  
seconds.  
or  
to choose a value from 0 to 990  
40  
 
REDUCING SQUELCH TAIL  
If you are communicating with a repeater or another station using  
subaudible tones, you can eliminate the squelch tail (the burst of  
noise the other person hears when you stop transmitting) by turn-  
ing on the transmit delay option. When you turn on this feature  
and use CTCSS, the radio continues to transmit for a short period  
of time after you release PTT, but then it immediately drops the  
subaudible tone. This causes the other radio to close the squelch  
before there is “dead air,” preventing the squelch tail.  
Use the Main Menu (see “Using the HTX-400’s Menus” on Page  
16) to set the transmit delay option, . Then, with t.dy and the  
current status displayed, press  
off.  
or  
to turn this feature on or  
BUSY CHANNEL LOCKOUT  
Use the Main Menu to set the busy channel lockout (see “Using  
the HTX-400’s Menus” on Page 16). The lockout prevents the  
transceiver from transmitting while it is receiving a signal. With  
the radio’s preset value bCLO oF displayed, press  
or  
to  
change the display to bCLO oN. Repeat this step to change the  
display back to bCLOoFto disable the lockout .  
41  
 
TROUBLESHOOTING  
If your transceiver is not working as it should and it displays an  
error message, these suggestions might help you eliminate the  
problem. If the transceiver still does not operate properly, take it  
to your local RadioShack store for assistance.  
You see  
S-SHORT  
Possible Cause  
Remedies  
If the transceiver  
detects a shorted  
external microphone  
connection, it auto-  
matically switches off  
power to the audio  
amplifier and dis-  
plays S-SHORTto  
indicate a short cir-  
cuit.  
Remove the con-  
nected micro-  
phone and  
replace it, or use  
the internal micro-  
phone.  
PLL-Error  
EEP-Error  
Indicates a PLL cir-  
cuit malfunction due  
to a defect in the  
VCO circuit or bias  
supply.  
Turn power off  
then on again.  
The EPROM infor-  
mation needs to be  
reset.  
Reset the trans-  
ceiver. See  
“Resetting the  
HTX-400” on  
Page 44.  
42  
 
CARE AND MAINTENANCE  
Your RadioShack HTX-400 Mini Handheld 70-Centimeter FM  
Amateur Transceiver is an example of superior design and  
craftsmanship. The following suggestions will help you care for  
your transceiver so you can enjoy it for years.  
Keep the transceiver dry. If it gets wet, wipe it dry  
immediately. Liquids might contain minerals that  
can corrode the electronic circuits.  
Use and store the transceiver only in normal tem-  
perature environments. Temperature extremes  
can shorten the life of electronic devices, damage  
batteries, and distort or melt plastic parts.  
Keep the transceiver away from dust and dirt,  
which can cause premature wear of parts.  
Handle the transceiver gently and carefully. Drop-  
ping it can damage circuit boards and cases and  
can cause the transceiver to work improperly.  
Use only fresh batteries of the required size and  
recommended type. Batteries can leak chemicals  
that damage your transceiver’s electronic parts.  
Wipe the transceiver with a damp cloth occasion-  
ally to keep it looking new. Do not use harsh  
chemicals, cleaning solvents, or strong detergents  
to clean the transceiver.  
Modifying or tampering with the transceiver’s internal compo-  
nents can cause a malfunction and might invalidate its warranty  
and void your FCC authorization to operate it. If your transceiv-  
er is not performing as it should, take it to your local Ra-  
dioShack store for assistance.  
43  
 
USING THE KEYPAD DIAGNOSTIC  
The HTX-400 has a built-in diagnostic program that lets you con-  
firm whether the keypad switches are functioning correctly. To  
use this diagnostic program, follow these steps.  
1. Hold down MO (REV) and turn on the transceiver.  
2. Press MO (REV) again. PrESSdnappears.  
3. Press  
. If the action is correct, PrESSUpappears.  
4. Press . If the action is correct, PrESMrappears.  
5. Press MR (MW). If the action is correct, PrESSScappears.  
6. Press SC (RPT). If the action is correct, PrESSbpappears.  
7. Press  
appears.  
(BEEP). If the action is correct, PrESS Lc  
8. Press LOCK (C). If the action is correct, Fappears.  
9. Press FUNC. If the action is correct, PrESMoappears.  
10. Press MO (REV). If this action is correct, GOOD appears  
briefly and then the set frequency appears again.  
RESETTING THE HTX-400  
If the transceiver’s display locks up or the transceiver does not  
work properly after you turn it on, you might need to reset it.  
Caution: This procedure clears all the information you have pro-  
grammed into the transceiver. Before you reset the transceiver,  
try turning it off then on again to see if it begins working properly.  
FUNC MO  
To reset the transceiver, turn it off then hold down  
+
and  
iniTial  
turn it on again.  
appears to confirm the reset opera-  
FUNC MO  
.
tion. Release  
+
44  
 
SPECIFICATIONS  
GENERAL  
Frequency:  
RX .............................................................. 420–470 MHz  
TX ............................................................... 430–450 MHz  
Extended TX Range.................................... 420–450 MHz  
Frequency Generation .............................. PLL Synthesizer  
Frequency Stability ................................................ ± 5 ppm  
Operating Temperature ........... 14° to 131°F (–10° to 55°C)  
Power Source ............................................... DC 3.0V to 9V  
Modulation .................................................................... F3E  
Impedance .............................................................. 50 ohm  
Dimensions (HWD) ....................... 21/4 × 33/8 × 11/16 inches  
85 × 58 × 26.5 mm  
Weight (without batteries) ............................. 4.2 oz (120 g)  
RECEIVER  
Circuit Type ................. Dual Conversion, Superheterodyne  
IF Frequency:  
1st IF ................................................................ 30.85 MHz  
2nd IF ................................................................... 450 kHz  
Sensitivity ........................................ 0.22 µV for 12 dB SND  
Selectivity ........................................................... 50 dB Min.  
Spurious and Image Rejection ........................... 60 dB Min.  
Intermodulation .................................................. 60 dB Min.  
Distortion ............................................................ 10% Max.  
S/N Ratio ........................................................... 35 dB Min.  
Audio Output @10%THD ................... 90 mW 16 Ohm, BTL  
TRANSMITTER  
Power Output .................... 200 mW, DC 3.0V/1W, DC 9.0V  
Distortion ....................................................................... 5%  
Deviation ................................................................. ± 5 kHz  
S/N Ratio ................................................................... 36 dB  
Current Drain ..................... 600 mA, DC 3V/900mA DC 9V  
Specifications are typical; individual units might vary. Specifica-  
tions are subject to change and improvement without notice.  
45  
 
NOTES  
46  
 
47  
 
Limited One-Year Warranty  
This product is warranted by RadioShack against manufacturing defects in  
material and workmanship under normal use for one (1) year from the date of  
purchase from RadioShack company-owned stores and authorized Ra-  
dioShack franchisees and dealers. EXCEPT AS PROVIDED HEREIN, Ra-  
dioShack MAKES NO EXPRESS WARRANTIES AND ANY IMPLIED  
WARRANTIES, INCLUDING THOSE OF MERCHANTABILITY AND FIT-  
NESS FOR A PARTICULAR PURPOSE, ARE LIMITED IN DURATION TO  
THE DURATION OF THE WRITTEN LIMITED WARRANTIES CONTAINED  
HEREIN. EXCEPT AS PROVIDED HEREIN, RadioShack SHALL HAVE NO  
LIABILITY OR RESPONSIBILITY TO CUSTOMER OR ANY OTHER PER-  
SON OR ENTITY WITH RESPECT TO ANY LIABILITY, LOSS OR DAMAGE  
CAUSED DIRECTLY OR INDIRECTLY BY USE OR PERFORMANCE OF  
THE PRODUCT OR ARISING OUT OF ANY BREACH OF THIS WAR-  
RANTY, INCLUDING, BUT NOT LIMITED TO, ANY DAMAGES RESULTING  
FROM INCONVENIENCE, LOSS OF TIME, DATA, PROPERTY, REVENUE,  
OR PROFIT OR ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSE-  
QUENTIAL DAMAGES, EVEN IF RadioShack HAS BEEN ADVISED OF  
THE POSSIBILITY OF SUCH DAMAGES.  
Some states do not allow the limitations on how long an implied warranty  
lasts or the exclusion of incidental or consequential damages, so the above  
limitations or exclusions may not apply to you.  
In the event of a product defect during the warranty period, take the product  
and the RadioShack sales receipt as proof of purchase date to any Ra-  
dioShack store. RadioShack will, at its option, unless otherwise provided by  
law: (a) correct the defect by product repair without charge for parts and la-  
bor; (b) replace the product with one of the same or similar design; or (c) re-  
fund the purchase price. All replaced parts and products, and products on  
which a refund is made, become the property of RadioShack. New or recon-  
ditioned parts and products may be used in the performance of warranty ser-  
vice. Repaired or replaced parts and products are warranted for the  
remainder of the original warranty period. You will be charged for repair or re-  
placement of the product made after the expiration of the warranty period.  
This warranty does not cover: (a) damage or failure caused by or attributable  
to acts of God, abuse, accident, misuse, improper or abnormal usage, failure  
to follow instructions, improper installation or maintenance, alteration, light-  
ning or other incidence of excess voltage or current; (b) any repairs other  
than those provided by a RadioShack Authorized Service Facility; (c) con-  
sumables such as fuses or batteries; (d) cosmetic damage; (e) transporta-  
tion, shipping or insurance costs; or (f) costs of product removal, installation,  
set-up service adjustment or reinstallation.  
This warranty gives you specific legal rights, and you may also have other  
rights which vary from state to state.  
RadioShack Customer Relations, 200 Taylor Street, 6th Floor,  
Fort Worth, TX 76102  
04/99  
We Service What We Sell  
08A99  
Printed in Korea  
 

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