Radio Shack HTX-400 User Manual

Cat. No. 19-1104

OWNER’S MANUAL

Please read before using this equipment.

HTX-400

Mini Handheld 70-Centimeter FM

Amateur Transceiver

FEATURES

Your RadioShack HTX-400 Mini Handheld 70-Centimater FM
Amateur Transceiver is compact and lightweight, making it easy
to carry almost anywhere. The crystal controlled circuitry pro­vides accurate and stable frequency selection, making it an ideal
choice for your amateur communications needs.

Note

: You must have a Technician Class or higher Amateur Ra­dio Operator’s License, and a call sign issued by the FCC, to le­gally transmit using this transceiver. Transmitting without a
license carries heavy penalties. Getting a license is easier than
ever. See “Introduction t o Amate ur Radio ” on Page 7 for m ore in­formation.

Here are some of your transceiver’s features.

Up To 1 Watt Output

— the transceiver transm its at 200 mW out­put when powered by int erna l al kaline batteries, or at 1 W att o ut­put when pow ered by an ex ternal 9-volt power source.

CTCSS
Tone

(Continuous Tone Coded Squelch System)

— both encodes and decodes 47 subaudible tones to help

Subaudible

reduce interference from other nearby systems operating on the
same frequency.

Repeater Offset

— lets you select t he appr opriate offs et value to

match a local repeater.

Scan

— the transceiver s cans the frequency ran ge and t he mem-

ory locations for transmissions.

Power Save

— conserves battery pow er wh en t he trans c eiv er i s

not transmitting or receiving.

Programmable Frequency Steps

— let you set the frequency
increment for tuning or scanning t o 5, 10, 12.5, 1 5, 20, 25, 50 k Hz,
or 1 MHz steps.

©1999 Tandy Corporation.

RadioShack and Adaptaplug are registered trademarks used by Tandy Corporation.

All Rights Reserved.

2

Paging Tones

— you can set the radio to play a shor t, sele ctable
paging tone when it transmits, and sound the same tone when it
receives a signal.

Signal Strength Indicator

— a graduated bar show s the relat ive

strength of the received signal.

Time-Out Timer

terval from 0 to 16

Busy Channel Lock Out

— lets you set a maximum tr ansmissi on time in-

1

/2 minutes in 10-second increments.

— prevents tran smitt ing wh ile the s e-

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 Mic r ophon e J ack

— let you con­nect 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 button s perform multiple function s. The ab bre­viation or symbol for a function is printed on, below, or above
each button.

To activate ce rtain transceiv er features, you mus t press
(function) and another button at the same time. Those key com­bination instructions are printed as the first button name, +, then
the second button name. For example,
hold down

Button names are printed in small, bold, capital letters such as

BEEP

display are printed using a distinctive typeface, such as

446.100

FUNC

while you press

or SC. Words, symbols, and numbers that appear on the

or

BUSY

.

LOCK

FUNC+LOCK

.

FUNC

means

FCC INFORMATION

This device complies wit h Part 15 of the FCC Rules . Ope ration i s
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 un­desired 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 Repeater s ...................................... ...... ....... 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

Temporaril y Locking Out (Skipping) Locations

During Memory Scanning ............................... ...... ... 34

Continuous Tone Coded Squelch System Features ......... 35

Tone Paging ..................................................................... 37

Sending Pag ing 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

Po wer 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 any­where! All you need is an Amateur Radio Operator’s License
(Technician Class or higher) issued by the Federal Communica­tions Commissio n (FC C). If you do not h av e a l ic ens e, it is easier
than ever to get one, and help from licensed operators is avail­able. Here are a few tips to help you get started.

You can turn on your transceiver and sca n the entire band to hear
what is going on;

you get your license

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 op­erate without a license.

Find out if there is a ham rad io club in your area. Mos t cl ubs w el ­come newcomers and are glad to help you get your license.
There are thousands of clubs across th e country, so there is prob­ably one in or near your community. The staff at your local Ra­dioShack 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 Radi o Relay League
(ARRL) at the following addres s to find out how to conta ct a local
affiliate. The ARRL is the national organization representing am­ateur 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.

however, do not attempt to transmit until

. If you transmit without a license, you are

The American Radio Relay League

225 Main Street

Newington, CT 06111

http://www.arrl.org

7

Start studying for the li cense ex ams. Do not b e intimid ated by the
word “study,” because most people can go from knowing abso­lutely nothing about amateur radio to passing the Novice and
Technician written exams in less than a month.

The exams test your knowle dge of bas ic radio regulation s and el­ementary 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. You r local Radio Shack store se lls

License Preparation

censes. While yo u are no lo nger re quired to l earn M orse code for
a Technician Cl as s lic ense, we encourag e y ou to learn it anyway
so you can advance to higher levels of operating privileges.

There is no fee to take the No vice exam. As so on 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 tes ts are admini stered by a three -member Vol unteer
Examiner Team. Contact the ARRL for a schedule of exam op­portunities in your area.

The Technician Class license lets you use the HTX-400 to com­municate directly w i th o the r op erators, and use repeaters for dis­tant communication.

Amateur radio is a great ho bby tha t has en ric hed the l iv es of m il­lions of people all over the w orld. The ARRL would be glad t o hear
from you if you need more information or would like to join!

study guides for amateur radio operator li-

FCC

8

PREPARATION

POWER SOURCES

You can operate your transceive r from any of thre e 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 tw o AA batte ries (not supp lied) for p ow­er. For the best performance and longest life, we recommend Ra­dioShack alkaline batteries.

Cautions:

• Use only fresh batteries of the required size and recom­mended type.

• Do not mix old and new batteries, d ifferent types of b atte ries
(standard, alkaline, or rechargeable), or rechargeable bat­teries of different capacities.

Follow these steps to install batteries.

LOCK Tab (on bottom)

1. Move the
marked on the bottom of the transceiver.

tab in the opposite direction of the arrow

LOCK

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

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. T he battery s ymbol ( ) constantly in ­dicates the battery strength. When only one or two bars appear
inside the battery strength indicator, replace both batteries as
soon as possible.

Warning

burn or bury them.

Caution

for a two week period, remove the batteries. Batteries can leak
chemicals that can destroy electronic parts.

: Dispose of old batteries promptly and properly. Do not

: If you do not plan to use the transceiver with batteries

BAT

appears briefly and the grad-

BAT

indicates the

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 powe r cord dir ectly to your powe r supply or add an ac­cessory 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.

REGULATED POWER SUPPLY

AMP

3

13.8 VDC

USING NI-CD OR NI-MH BATTERY
POWER

You can use either Ni-Cd or Ni-MH batt erie s to po wer yo ur H TX­400; however, you cannot recha rge these b atteries while they are
inside the HTX-400. You can use a separa te externa l charge r for
recharging the batteries o utside the radi o. Your local Radi oShack
store carries a selection of suitable batteries and chargers.

As these batteries provide less voltage than that typically

Note:

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 V EHICLE 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-to­DC power adapter and a size I Adaptaplug
with TIP se t to +. Both are available at your local RadioShack
store.

Cautions:

Y ou mu st use a pow er sourc e that supp lies 9V DC
and delivers at least 900 mA. Its center tip must

!

be set to positive and its plug must fit the HTX-

DC 9V

400's
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 bat­tery power.

1. Insert the Adaptaplug into the HTX-400’s

2. Plug the other end of the adapter into the cigarette-lighter
socket in the vehicle.

jack. Using an adapter that does not meet

®

(neither supplied)

jack.

DC 9V

12

CONNECTING THE ANTENNA

Place the threaded ba se socket of the supplied antenna over the
antenna connector on to p of the transc eiver and tu rn the antenna
clockwise to tighten it

. Turn it clockwise to remove it.

U

Caution:
Note:

an SMA-to-PL-259 adapter. This adapter, as well as suitable an­tennas, are available through your local RadioShack store.

Do not over-tighten the antenna

You can connect an external antenn a to the HTX-400 using

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 supp lied wrist s trap to the top of the b elt 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 (con­sisting of a microphone and speaker) to the transceiver so you
can use it privately. Lift the hinged, rubber dust cover from the

and

MIC

the plug of an optional voice activated headset with micro­phone, or an optional communication headset, i nto t he j acks.

jacks on the top of the transceiver, then insert

SPK

14

Caution:

Use only microphone and speaker accessories that do
not share a common gro und for the speaker and the m icrophone .
Doing otherwise might damage the transceiver.

Inserting a head set’s plug automati cally disconnec ts the in-

Note:

ternal spea ker.
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 se­lection of suitable communications headsets, earphones, and
separate components.

The following schematic diagram shows the typical wiring for a
suitable external mic and speaker.

Speaker­Plug

Barrel

External Speaker

–

+

Tip

MIC Plug

Barrel

External Microphone

Ω

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
HTX-400. (The

option app ears). Hold down

CS

while turning on the

FUNC

FUNC

then re-

peatedly press Wor V to step through the other option s. Rel ease

and press V or W to change an option’s setting.

FUNC

Main Menu

Options

CS

Frequency
Step

bCLO

Busy Chan­nel Lockout

t.dY

Transmit
Delay Time

Sd

Scan Delay
Time

Setting

( ) = default

setting Description Page

.0050

(MHz),

.0100

,

(.0125), .0150
.0200, .0250
.0500, 1.000

(Off)
On

Off
(On)

1 to 30 seconds
(5)

Sets the increment
for scanning the
band.

,

,

Prevents transmit­ting while receiving
a signal.

Prevents
squelch tail.

Sets the scanning
restart time.

39

41

41

32

16

Main Menu

Options

Setting

( ) = default

setting Description Page

tot

Time out
Timer

PS

Power Save

r

Repeater
Offset

(Off)
On 10-990 seconds

(Off)
On

0.00

8.00

–

in 50kHz steps.

(5.00)

MHz

Limits trans mit time. 40

Cycles power
(PS flashes) to the
receiver section to
conserve batteries.
The circuit remains
off then turns on
briefly to check for
an incoming signal.

Sets the offset in 50
kHz steps between
the repeater’s trans­mit and receive fre­quencies.

40

27

17

The Tone Set Menu lets you set features that rel ate to sound and
the CTCSS tones. To access these settings, turn on the HTX-400
then

hold down

pears.) Press

FUNC

and press

FUNC

+ V or W to select the opti on, the n V or W to

T.SET

. (The tone option ap-

change the setting.

Tone Set

Option

tone

Subaudible
Tone

rC

Receive
Tone

tC

Transmit
Tone

MEL

Tone Paging

Setting

( ) = default setting Description Page

(Off)
On

See the table
on Page 36.
(67.0)

See the table
on Page 36.
(67.0)

(1), 2, 3, 4, 5 Lets you select a

Lets the HTX-400
transmit and
receive the Sub­audible Tone
(CTCSS) fre ­quencies so you
can listen only to
other units with
the same tone.

Lets you select
one of 47 different
receiving sub­audible tones or
turn the feature
off

.

Lets you select
one of 47
different subaudi­ble tones or turn
the feature off

tone to receive or
transmit.

.

35

35

35

37

18

A QUICK LOOK AT THE CONTROLS

Most of the controls of t he H T X-400 hav e m ul tip le func tions. Use
the following chart to review the function of each control.

VOL/OFF

SQ

PTT

Speaker

Key/Control Use it to:

VOL/OFF

SQ

Turn the radio on/off.
Adjust the volume.

Set the squelch level
to block weak signals.

Microphone

U

Use with the

FUNC + Key to:

Access the Main
Menu.

N/A

()

Change (increase) the
frequency by the value
set for
menu option on Page

16).

(see the first

CS

Directly changes
the frequency, one
digit at a time.
Repeatedly press

V

to access each
digit of the dis­played frequency.

19

Key/Control Use it to:

Use with the

FUNC + Key to:

(T.SET)

MO (REV)

(BEEP)

MR (MW)

SC (RPT)

Change (decrease)
the
frequency by the value
set for
menu option on Page

16).
Press to override

squelch. Press and
hold to cycle through

rC, tC, r

tings.
Turn on the display’s

backlight for 4 sec­onds.

Enter memory setting
mode.
used memory location
appear.

Starts and stops scan­ning. Hold down and
power on to access
expanded band cover­age
(420–450 MHz).

(see the first

CS

, and CS set-

MR

and the last

Accesses the Tone
Set Option menu
and settings.

Reverse the
repeater offset.

Enable/disable the
key tone.
appears when the
key tone is enabled.

In memory mode,
starts the display
flashing. Then use

or to
access a frequency
to store in a mem­ory location.

Set the radio to
simplex or duplex
mode when in VCO
mode. Set the
repeater offset for a
memory location
when in memory
mode.

20

Key/Control Use it to:

Use with the

FUNC + Key to:

C (LOCK)

PTT

(Push To Talk)

Press once to display
and switch to the cur­rent call frequency.
Hold down to change
the call frequency and
associated parame­ters, such as repeater
offset and CTCSS
tones.

Hold down to trans­mit. Press to store the
settings.

Lock the control
(except

PTT, MO

,

VOL

Press again to
unlock the controls.

Swap the input and
output frequencies
for repeater opera­tions.

,

, and SQ).

21

A QUICK LOOK AT THE DISPLAY

1

2
3

4

5

6 7 8 9 10 11

1.F: appears when the

2.TX: appears when the radio is transmitting.

3.

4.

5. : indicates the battery strength.

6.

7.

8. : the stronger the signal, the more boxes appear.

9.

10.

11.MR (Memory Channel indicator): for use or for programming.

12. : paging tone active.

13. : key tone enabled.

14. : keypad control disabled to prevent accidentally

15.PS: appears when power save is enabled.

16.

17.ã: appears to indicate a positive repeater offset. – indicates a nega-

: appears when the radio receives a signal.

BUSY

: appears when tone squelch is on and the radio receives a

CALL

matching tone.

(Signal/RF Indicator): shows the level of an incoming signal.

S-RF

When transmitting, shows the relative output signal strength.

: appears when you turn on the radio — the signal strength

BAT

meter then indicates the battery strength.

Bars show remaining battery power when MO and
held down at the same time.

Alpha-Numeric Display
Memory Location

changing a setting.

: appears when Tone Squelch (CTCSS) is enabled.

TSQ

tive repeater offset.

: shows the memory channel in use.

key is pressed.

FUNC

: shows frequency and messages.

121314151617

PTT

switch are

22

OPERATION

TURNING ON THE HTX-400

To turn on the HTX-400, rotate
The HTX-400 sounds a b rief melody if the k ey to ne fe ature is en­abled. Then
used frequency appears.

HELLO

appears for about 2 seconds and the last

VOL/OFF

clockwise until it clicks.

SELECTING FREQUENCIES
(DIRECT TUNING)

You tune to the desired f requencies i n the VFO (variable frequen­cy oscillator) mo de. You ca n either s tep to a s pecific frequenc y or
directly select the frequency.

To step to a frequency, repeatedly press or hold down
until the display shows the desired frequency.

The HTX-400 steps up or down in increments which you

Note:

set using the Frequency Step menu opti on. (See “Setting th e Fre­quency Step” on Page 39).

To directly enter a frequency, press
from the left flashes), then press or to change the number.
Press
each number of the desired frequency, then press
the selection.

Note:

and 470 MHz, and transmit between 430 and 450 MHz. To ex­pand the frequency coverage, see “Changing the Transmit Fre­quency Range” on Page 38.

+ again to select the next digi t. Repeat this to s elect

FUNC

The HTX-400 is preset to receive frequencies between 420

+ (the second digit

FUNC

PTT

or

to store

23

RECEIVING TRANSMISSIONS

Follow these steps to receive standard transmissions.

1. With the radio on, rotate
a hissing sound. Then slowly rotate
the noise stops.

Notes:

•

• Volume, po wer , an d squelch are combined in on e c ontro l.

• If the HTX-400 picks up unwanted, weak transmissions,

2. Set

appears when the HTX-400 receives a standard

BUSY

transmission or if the squelch is open. If the transmission
uses CTCSS tones,

The inner control is
the outer control is

rotate
for these transmissions. If you want to hear weak trans­missions, rotate SQ counterclockwise. When you do this,
you might hear hissing between transmissions.

VOL/OFF

clockwise to prevent the squelch from opening

SQ

to a comfortable listening level.

counterclockwise until you hear

SQ

clockwise just until

SQ

also appears.

CALL

(volume) and power on/off, while

VOL

(squelch).

SQ

TEMPORARILY OPENING SQUELCH

If you use the Tone Squel ch (CTCSS) featu re, you might not h ear
a trans

mission on the current fre quenc y. T
squelch so you ca n hear a ll trans mission s o n the freq uency , hold
down

. To resume normal operation, release MO.

MO

o temporarily open t he

24

TRANSMITTING

There are two basic types of communication possible with this
transceiver: radio-direc t-to -radi o (s im pl ex) or rad io -to re pea ter-t o
radio (duplex). Simplex operation uses the same frequency to
send and receive. Du plex o per ation u ses o ne frequ ency to trans ­mit and another to receive. For more information about duplex,
see “Understanding Repeaters” on Page 26.

Caution:

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

4. Release

It is illegal to tra nsmit if you do no t have at least a Tech-

, then speak slo wly an d clea rly into the mi cro-

PTT

phone.

Note:

range,

appears while you transmit.

TX

If you try to transmit outside the transmit frequency

inhibit

PTT

briefly appears.

when you finish transmitting.

25

UNDERSTANDING REPEATERS

Operation through a repeater, where you transmit on one fre­quency and recei ve on a nother , is ca lled
ation direct to a nother station , wh ere yo u tr ansmit a nd receive on
the same frequency, is called

A repeater is a station that receives a signal on one frequency

input

(the
ent frequency (the
ically located at the tops of tal l building s or on antenna tow ers, so
a relatively low-po wer s ig nal ca n re ac h th e re pea ter. The repeat­er retransmits th e sig nal a t a h igher power . This gives your trans­ceiver the ability to communicate over a much greater range.

To use a repeater, you m ust kno w the rep eater’s input an d output
frequencies. Repeaters are usually identified by their output fre­quency. Thus, a repe ater that has an outpu t frequency of 442.2 00
is referred to as “the 442.2 repeater.” To determine the input fre­quency, you must know the frequency
the 70 cm-meter band) and the
MHz to the output, or – if you subtract 5 MHz from the output).

Whether the offset is positive or negative depends on:

frequency) and then retransmits that signal on a differ-

output

• which part of the band the repeater operates on

• local convention

• proximity of repeaters using the same two frequencies

simplex

frequency). Repeater ant ennas are typ-

duplex

operation.

offset

(typically 5 MHz for

offset direction

operation. Oper-

(+ if you add 5

To determine the offset and the direction, obtain a copy of

ARRL Repeater Handbook

dioShack store or directly from the ARRL) which lists the loca­tions of repeaters as well as their frequency and offset
information.

above the displayed frequency indicates a positive offset,

A

+

while a – above the frequency indicates a negative offset. If nei­ther

26

or – appears, the HTX-400 is set for simplex operation.

n

+

(available from your local Ra-

The

SETTING THE REPEATER OFFSET
FREQUENCY

The HTX-400 ’s default repeater off set is 5 MHz, whi ch appears
as

5.00

This setting on ly aff ect s the VFO mode. If yo u s av ed a fre-

Note:

quency offset in a memory, that setting is not affected.

1. With power off, hold down

2. Hold down
current offse t
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

)

. Follow these steps to change the offset.

(MHz

and turn on the HTX-400,

FUNC

and repeatedly press until r and

FUNC

appear.

to store the setting and exit the menu.

PTT

appears if no offset is currently

5.00

the

TURNING DUPLEX
OPERATION ON AND OFF

To turn on duplex (repeater use) operation for the VFO mode,

FUNC

0.00

+ SC (

press
ue is not
appears above the displayed frequency. Press
again to turn it off.

). Provided the current repeater offset val-

RPT

, the current offset i ndica tor (+ above or – below)

+ SC (

FUNC

RPT

27

)

SETTING THE REPEATER OFFSET
DIRECTION

1. Set an offset frequency other than 0.00.

2. Press

above or

3. Press

tion.

FUNC + SC (RPT)

below).

–

+ MO (

FUNC

to see the curr e nt off se t di rec t io n (

) to change the repeater offset direc-

REV

+

To save this setting in a memory location, must be

Note:

flashing before you store the settings (s ee “Using the C alling-Fre­quency 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.

MR

REVERSING THE TRANSMIT AND
RECEIVE FREQUENCIES

To swap the input and output frequencies, press
example, if you have set the radio to repeater operation on

442.200 with a positiv e o ffse t of 5 MHz , th e rad io would normally
receive on 442.200 and transmit on 447.200 MHz. After you
press

FUNC+PTT,

on 442.200.
This feature is useful if you want to determine whether you are

close enough to ano ther station to c ommunicat e on a simple x fre­quency. While the other station is transmitting, reverse the fre­quencies. If you can still hear the other station, you are hearing
their signal directly and you do not need to use the repeater.

the radio will receiv e on 4 47.2 00 an d tran smit

FUNC+PTT

. For

28

MEMORY OPERATION

Your HTX-400 has 30 standard memory locations that you can
use to store frequenci es for quick acc ess. For each memory loca ­tion, you can also store ot her settings such as the repeater offset ,
CTCSS tones, and frequencies to pass or lock out during scan­ning.

STORING A TRANSMIT/RECEIVE
FREQUENCY

1. Press

2. Repeatedly press or to select the desired memory
location.

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

FUNC

calling frequency. Then press or to select the desired
offset. Press

6. Press
remove an offset for simplex operation, set the repeater off­set to

7. If desired, set the tone squelch settings (see “Continuous
Tone Coded Squelch System Features” on Page 35).

8. Press
memory mode.

MR

and the last used memory location appear.

.

MR

appears if the memory location is empty.

------

FUNC+MR

+ SC. The HTX-400 displays the current offset for the

FUNC

0.00

PTT

. The selected memory location and

to store your setting.

PTT

+

to select the offset direction (+ or –). To

REV

.

to store all settings, then press MR to exit the

MR

29

RECALLING MEMORIES

To recall saved memory settings, press MR so appears. Then

MR

press or to select the desired memory location.
Press MR again to return to the VFO mode, (See “Selecting Fre-

quencies (Direct Tuning)” on Page 23.)

CLEARING A SINGLE MEMORY

Follow these steps to clear any single memory location.

1. Press

2. Repeatedly press or to select the desired memory
location.

3. Press
flash.

4. Hold down
clears and
empty.

5. Press MR to exit the memory mode.

To clear all memory loca tions, see “Resetting the HTX-

Note:

400” on Page 44.

MR

. and the last used memory location appear.

MR

FUNC+MR

. The selected memory location and

for several seconds. The memor y loca tion

FUNC

appears to confirm that the location is

------

MR

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 s tore a differ ent frequenc y into mem ­ory as well as other settings associated with that frequency,
such as the repeater offset and CTCSS tone.

1. Press

2. To change the frequency, hold down

to display the current calling frequency.

C

until and

C

MR

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

FUNC+SC

. The HTX-400 displays the current offset for the

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

6. To select the offset direction (+ or – ) , pr ess

PTT

.

FUNC + REV.

To
remove an offset for simplex operation, set the repeater
offset to

Note:

0.00

.

MR

While and

C

appear, you can program other set­tings such as CTCSS tones (see “Continuous Tone Coded
Squelch System Features” on Page 35.)

To enable the calling frequen cy, press

at any time. Th e tr ans-

C

ceiver immediately tunes to that frequenc y with the setti ngs you
programmed. To exit th e calling frequ ency mode, pre ss C again.

C

31

SCANNING OPERATION

SCANNING FOR ACTIVE FREQUENCIES

1. To search for activity on a frequency, press SC. The trans­ceiver 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,

SC

again.

press

Using Scan Delay

If the HTX-400 stops on a signa l during scanni ng, then
stops, the scan d elay feature d elays the c ontinu ation o f sca nning
to allow time f or the signal to resta rt. Acc es s the M ai n Me nu (s ee
“Using the HTX-400’s Menus” on Page 16) to set the value. With

Sd

and the current delay ti me sh own,

new delay time (between 1 and 30 seconds).

press or to select the

that signal

SCANNING STANDARD MEMORY
LOCATIONS

1. Press

2. To change the scanning direction, press or .

3. To stop scanning, press

32

MR

scans all locations except empty locations and the ones you
programmed to be passed during scanning.

MR

appears), then press SC. The transceiver

(so

again.

SC

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 scan­ning) a spe c ific location during scanning.

MR

1. Press

2. Repeatedly press or to select the desired memory
location.

3. Press
flash.

4. To set the HTX-400 to skip the memory location, press
then press or so

. and the last used memory location appear.

MR

FUNC+MR

. The selected memory location and

SCSP ON

(scan skip) appears.

MR

SC

,

To inc lu de th e di splaye d lo cation during scanning, pre ss
or so

SCSP oF

5. When you finish, press SC again, then press

appears.

PTT

the setting.

to store

33

Temporarily Loc king 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

PASS

FUNC

.

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 a nd have the HTX-400 inc lude th e skipp ed
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 l ock ou t all bu t two acti ve loc ation s and th en
lock out one more,

briefly appears a nd the transceiver c on-

EMPTY

briefly appears and scanning stops.

34

CONTINUOUS TONE CODED
SQUELCH SYSTEM FEATU RES

Your HTX-400 can transmit and receive a low-level, selectable
subaudible tone at th e s ame tim e a s i t tran sm its (TX) o r rec eiv es
(RX) a regular signal. This speci al ton e lets you lis ten on ly to oth­er radios set to the same tone frequency when y ou us e t he HTX­400 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

tone on

or

2. Press or to turn on the option .

+ . The current tone setting appears (

FUNC

).

tONE on

tONE oF

appears

.

3. To set a receive (RX) tone, press
Then press or to select a tone frequency from the list
on Page 36.
both the transmit and receive frequencies.

4. To set a transmit (TX) tone, press
Then press or to select a tone frequency from the list
on Page 36.

5. Press

For this example, 67.0 Hz was selected for

to store all the settings.

PTT

+. rC appears.

FUNC

+. tC appears.

FUNC

35

To select and store a CTC SS subaudible tone in a memory loc a-

MR

.

tion, press

MR

and the last used memory location appear.
(In the examples sho wn on the pre cedin g page , memo ry loc ation
2 is used.) Then follow the preceding Steps 1–5.

Subaudible Tone Frequencies (Hz)

67.0 114.8 186.2

69.3 118.8 189.9

71.9 123.0 192.8

74.4 127.3 196.6

77.0 131.8 199.5

79.7 136.5 203.5

82.5 141.3 206.5

85.4 146.2 210.7

88.5 151.4 218.1

91.5 156.7 225.7

94.8 159.8 229.1

97.4 162.2 233.6

100.0 167.9 241.8

103.5 173.8 250.3

107.2 179.9 254.1

110.9 183.5 Off

36

TONE PAGING

You can set the HTX-40 0 t o s oun d an alert tone when it rec eiv es
a transmission th at inc ludes the c urrentl y se t suba udible rece ive­tone (or any transmission, if the receive-tone or the tone feature
is set to off). Turn off the radio, then press while you turn the
HTX-400 on again. appears.

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 featur e 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
number from

3. Repeatedly press either or to step through the five dif­ferent tones. If key tone is enabled, each tone sounds as
you select its number.

4. Press

PTT

and press (

FUNC

to 5 appear. Release

1

to store your selection and exit the menu.

T.SET

) four times.

.

FUNC

MEL

and a

SENDING PAGING TONES

To transmit the selected paging tone, press

PTT

.

while pressing

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 transceiv er to its extended ra nge, turn off the tra nsceiv­er, then hold down

To return to the standard frequency range, turn off the transceiv­er, then hold down SC and turn it on again.

LOCKING THE KEYPAD

To lock the transceiver’s keypad so you do not accidentally
change a setting, press
buttons except

and turn on the transceiver again.

SC

PTT

FUNC+LOCK

VOL

, ,

, and SQ.

. appears. This loc ks all

To unlock the keypad, press

FUNC

+

LOCK

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 le ast 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
key. To turn off the beep, pr ess
To restore the key tone, press

Note

: If the key tone feature is disabled, the power-on tone does

not sound.

FUNC

FUNC

+ (

+ (

BEEP)

. disappears.

BEEP

) again.

CHECKING THE CURRENT MEMORY
SETTINGS

If you hold down MO (
opens and the set valu es for receive tone (
tone (

tt on/off

offset (

r

Release

), and frequency step (CS) appear.

MO (REV

), scan skip co ndition (

) to turn on the squelch again.

) for longer than 1 second, the squelch

REV

rT on/off

SCSP

), transmit

)(if any), repeater

SETTING THE FREQUENCY STEP

To change the frequency increment used during scanning and
stepping to a frequency , use the Main Men u 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 settin g. 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

With PS and the curre nt sta t us (on or

16).
or to turn this feature on or off.

“Using the HTX-400’s Menus” on Page

oFF

) displayed, press

TIME-OUT TIMER

When you communicate using repeaters, keep your transmis­sions as brief as possible. Most repeat ers have built-in tim ers 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 fo r the ti me-ou t time r. With

setting displayed, press or to choose a value from 0 to 990
seconds.

tot

and the current

40

REDUCING SQUELCH TAIL

If you are communicating with a repeater or an other stat ion using
subaudible tones, you can eliminate the squelch tail (the burst of
noise the other person hears wh en you stop transmitt ing) by turn­ing on the transmit delay option. When you turn on this feature
and use CTCSS, the radio continues to transmit for a sho rt period
of time after you release
subaudible tone. This causes th e other radio to close the sq uelch
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
current status displayed, press or to turn this feature on or
off.

, but then it immediately drops the

PTT

t.dy

and the

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
change the display to
display back to

bCLO

bCLO oF

bCLO

oF

to disable the lockout .

displayed, press or to

oN

. Repeat this step to change the

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 Possible Cause Remedies

S-SHORT

PLL-Error

EEP-Error

If the transceiver
detects a shorted
external microphone
connection, it auto­matically s witches off
power to the audio
amplifier and dis-

S-SHORT

plays
indicate a short cir­cuit.

Indicates a PLL cir­cuit malfunction due
to a defect in the
VCO circuit or bias
supply.

The EPROM infor­mation needs to be
reset.

to

Remove the con­nected micro­phone and
replace it, or use
the internal micro­phone.

Turn power off
then on again.

Reset the trans­ceiver. See
“Resetting the
HTX-400” on
Page44.

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 electr onic circuits.

Use and store the transceiver only in normal tem­perature environments. Temperature extremes
can shorten the life o f el ec tron ic dev ic es , da ma ge
batteri es, and distort or melt plastic pa rts.

Keep the transceiver away from dust and dirt,
which can cause premature wear of parts.

Handle the transcei ver ge nt ly an d caref ul ly. Dro p­ping it can damage circuit boards a nd 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 occasion­ally 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 compo­nents can cause a malfunction and might invalidate its warranty
and void your FCC authorizat ion to opera te it. If your transcei v­er is not performing as it should, take it to your local Ra­dioShack store for assis tance.

43

USING THE KEYPAD DIAGNOSTIC

The HTX-400 has a bu ilt-in diagnostic p rogra m tha t l ets y ou c on­firm whether the keypad switches are functioning correctly. To
use this diagnostic program, follow these steps.

1. Hold down

2. Press

3. Press . If the action is correct,

4. Press . If the action is correct,

5. Press

6. Press

7. Press
appears.

8. Press

9. Press

10. Press
briefly and then the set frequency appears again.

MO (REV

MO (REV

MR (MW)
SC (RPT)

(BEEP)

LOCK (C)

. If the action is correct,

FUNC

MO (REV)

) and turn on the transceiver.

) again.

. If the action is correct,

. If the action is correct,

. If the action is correct, F appears.

PrESS dn

. If the action is correct,

. If this action is correct,

appears.

PrESS Up

PrES Mr

PrESS Sc
PrESS bp

PrES Mo

appears.

appears.

PrESS Lc

appears.

GOOD

appears.

appears.

appears

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

grammed into the transceiver. Before you reset the transceiver,
try turning it off th en o n a gai n t o s ee if i t begins working properl y.

: This procedure clears all the information you have pro-

To reset the transceiver, turn it off then hold down
turn it on again.
tion. Release

44

iniTial

FUNC+MO

appears to confirm the reset opera-

.

FUNC +MO

and

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) ....................... 2

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

1

/4 × 33/8 × 11/16 inches

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. Specifica­tions are subject to change and improvement without notice.

45

NOTES

46

47

Limited One-Year Warranty

This product is war ranted by RadioShac k against manufactu ring defects in
material and workmanship under normal use for one (1) year from the date of
purchase from RadioShack company-owned stores and authorized Ra­dioShack franchisee s and dealers. EXCEPT AS PROVIDE D HEREIN, Ra­dioShack MAKES NO EXPRESS WARRANTIES AND ANY IMPLIED
WARRANTIES, INCLUDING THOSE OF MERCHANTABILITY AND FIT­NESS 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 PER­SON 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 WAR­RANTY, INCLUDING, BUT NOT LIMITED TO, ANY DAMAGES RESULTING
FROM INCONVENIENCE, LOSS OF TIME, DATA, PROPERTY, REVENUE,
OR PROFIT OR ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSE­QUENTIAL 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 exclusi on of incide ntal or con sequenti al damage s, so the a bove
limitations or exclusions may not apply to you.
In the event of a pro duct de fect dur ing the w arra nty per iod, take the produ ct
and the RadioShack sales receipt as proof of purchase date to any Ra­dioShack store. RadioShack will, at its option, unless otherwise provided by
law: (a) correct th e defect b y product r epair w ithout char ge for pa rts and la ­bor; (b) replace th e p ro duct w ith on e o f t he sam e o r simi lar d esign; or (c) re­fund the purchase price. All replaced part s and products, and produ cts on
which a refund is made, become the property of RadioShack. New or recon­ditioned parts and products may be used in the performance of warranty ser­vice. Repaired or replaced parts and products are warranted for the
remainder of the original warranty period. You will be charged for repair or re­placement 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 instruction s, improper installation or m aintenance, alteration, l ight­ning or other incidence of excess voltage or current; (b) any r epairs other
than those provided by a RadioShack Authorized Service Facility; (c) con­sumables such as fuses or batter ies; (d) cosmetic damage; (e) transpo rta­tion, shipping or insu ra nce co sts; o r (f ) cos ts of p rod uct r em ova l, insta l lation ,
set-up service adjustment or reinstallation.
This warranty gives you specific legal rights, a nd you may also have othe r
rights which vary from state to state.

RadioSha ck Customer Relations, 200 Taylor Street, 6th Floor,

Fort Worth, TX 76102

We Service Wh at We Sell

04/99

08A99 Printed in Korea