Radio Shack TRC-495 User manual

Cat. No. 21-1579
OWNER’S MANUAL
40-Channel CB Base Station Transceiver
Please read before usin
g
this equipment.
TRC-495
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2
FEATURES
© 1995 Tandy Corporation.
All Rights Reserved.
Radio Shack is a registered trademark used by Tandy Corporation.
Your Radio Shack TRC-495 40-
Channel CB Base Station Transceiv-
er is a compact, 40-channel CB spe-
cially designed for use as a Class D
citizen's band base station. The
TRC-495 transmits with the maxi-
mum power allowed by the FCC, so
your signal really gets out. Its built-in
PLL (phase-locked loop) frequency
synthesizer uses a precise frequency
reference crystal for reliable and ex-
act tuning.
You can operate the CB from either
120 volts AC or 12 volts DC, so you
can use it at home or the office, even
when AC power fails. With a base
station in your home or office and a
mobile CB in your vehicle, you can
stay in touch wherever you go, with-
out the expense of mobile telephone
operation. You can also talk with oth-
er CBs for business or just for fun.
Your CB also has the following valu-
able features:
Lar
g
e Analo
g
Meter — lets you see
how well you are “getting out,” and
how well others are “getting in.”
Scan — seeks out other CB users by
searching through all channels for
transmissions.
Switchable Noise Blanker and Au-
tomatic Noise Limiter — reduce in-
terference from ignition systems,
motors, and other electrical equip-
ment.
RF Gain Control — helps prevent
overloading from strong signals.
H
y
steresis Squelch Circuit — com-
pensates for signal fading and elimi-
nates signal chopping when you
listen to a broadcast.
Two Ceramic Filters — give superi-
or selectivity and freedom from adja-
cent channel interference.
CH9 Switch — lets you quickly
switch to Channel 9, used for emer-
gencies or motorist assistance.
Channel Displa
y
— shows the se-
lected channel in large red digits, for
easy viewing in most lighting condi-
tions.
NB, ANL, and SCAN Indicators —
show you when you are in the Noise
Blanker, Automatic Noise Limiter, or
Scan mode.
External Speaker and Headphone
Jacks — let you connect another
speaker or headphones to your CB.
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3
Note: You need a base station an-
tenna to operate this CB. Your local
Radio Shack store has a variety of
antennas. See “Connecting an An-
tenna.”
For your records, we urge you to
record the serial number of your CB
in the space below. You'll find the se-
rial number on the back panel of the
CB.
Serial Number _________________
Warning: To prevent fire or shock
hazard, do not expose this product to
rain or moisture.
This symbol is intended to alert
you to the presence of uninsulat-
ed dangerous voltage within the
product’s enclosure that might be
of sufficient magnitude to consti-
tute a risk of electric shock. Do not
open the product’s case.
This symbol is intended to inform
you that important operating and
maintenance instructions are in-
cluded in the literature accompa-
nying this product.
FCC STATEMENT
The Federal Communications Com-
mission (FCC) does not require you
to get a CB license to operate your
CB. However, you are required to
know Part 95 of
FCC Rules
. This in-
formation applies to the operation of
a Class D citizen's band CB. A copy
of Part 95 is enclosed with your CB.
Your CB might cause TV or radio in-
terference, even when it is operating
properly. To determine whether your
CB is causing the interference, turn
off your CB. If the interference goes
away, your CB iscausing the interfer-
ence. Try to eliminate the interfer-
ence by:
• Moving your CB away from the
receiver.
• Connecting your CB to an outlet
that is on a different electrical
circuit from the receiver.
• Contacting your local Radio
Shack store for help.
If you cannot eliminate the interfer-
ence, the FCC requires that you stop
using your CB.
RISK OF ELECTRIC SHOCK.
DO NOT OPEN.
CAUTION: TO REDUCE THE RISK OF
ELECTRIC SHOCK, DO NOT REMOVE
COVER OR BACK. NO USER-SERVICE-
ABLE PARTS INSIDE. REFER SERVIC-
ING TO QUALIFIED PERSONNEL.
CAUTION !
!
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4
TABLE OF CONTENTS
Installation ...................................................................................................... 5
Selecting a Location .................................................................................. 5
Connecting an Antenna ............................................................................. 5
Connecting the Microphone ....................................................................... 6
Connecting Power ..................................................................................... 7
Using Standard 120-Volt AC Power .................................................... 7
Using 12-Volt DC Power ..................................................................... 7
Connecting an External Speaker ............................................................... 8
Connecting Headphones ........................................................................... 8
Operation ........................................................................................................ 9
Receiving Transmissions ........................................................................... 9
Transmitting ............................................................................................. 10
Using Special Controls ........................................................................... 10
Using CH9 .......................................................................................... 11
Using SCAN ....................................................................................... 11
Using NB and ANL ............................................................................. 11
Using RF GAIN ................................................................................. 12
CB Courtesy ............................................................................................ 12
Maximum Range ..................................................................................... 12
Using Common 10-Codes ....................................................................... 13
Troubleshootin
g
........................................................................................... 14
Noise Reduction ...................................................................................... 15
Care and Maintenance ................................................................................. 16
Replacing the Fuse .................................................................................. 17
Specifications ............................................................................................... 18
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5
INSTALLATION
SELECTING A
LOCATION
Choose a location for your CB that is
near a standard AC power outlet and
your antenna installation and away
from sources of electrical noise.
CONNECTING AN
ANTENNA
An antenna is an important part of
your CB installation. Choose and in-
stall the antenna with care.
Consider the following when you in-
stall the antenna:
• Mount the antenna as far as
possible from soures of electri-
cal noise (power lines, trans-
formers, ignition systems,
electrical motors, and so on) and
keep the antenna's cable away
from these noise sources.
• Provide a good ground for the
antenna with UL-listed compo-
nents.
• Be sure the antenna cable's
shield is securely connected.
• Mount the antenna as high as
possible without exceeding 60
feet above the ground or 20 feet
higher than the highest point on
a building.
• For the best performance, the
antenna must be tuned (see the
instructions provided with the
antenna) and positioned verti-
cally.
Select an antenna with a PL-259
connector. This type of antenna
works most efficiently as a base sta-
tion antenna. For example, a 1/2-
wave base station antenna (Radio
Shack Cat. No. 21-967) is a high-effi-
ciency antenna that has omni-direc-
tional characteristics. You can use
this type of antenna for medium and
long-range communications.
Use coaxial cable with an impedance
of 50 ohms to connect the antenna to
your CB. We suggest you use RG-
58/U for lengths under 10 feet, or
RG-8/U for longer lengths, and keep
the length of the antenna cable to a
minimum.
Once you select the antenna, mount
it following the instructions supplied
with it. Then route the cable to the CB
and connect the cable to the ANT
connector on the back of the CB.
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6
Warning: When installing or remov-
ing a base station CB antenna, use
extreme caution. If the antenna starts
to fall, let it go! It could contact over-
head power lines. If the antenna
touches the power line, contact with
the antenna, mast, cable, or guy
wires can cause electrocution and
death. Call the power company to re-
move the antenna. DO NOT attempt
to do so yourself.
CONNECTING THE
MICROPHONE
Mount the supplied microphone clip
on the leftside oftheCB, horizontally
or vertically, using the two supplied
screws. Then slide the microphone
onto the microphone holder.
Connect the microphone cable to the
MIC jack on the front panel. Press
the tab on the top of the microphone
plug and match the notch in the plug
with the top notch in the jack. Then
insert the plug into the jack.
To remove the microphone cable,
press the tab and pull the plug out of
the jack. Never pull on the micro-
phone cable.
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7
CONNECTING POWER
You can power your CB from either
standard 120-volt AC or from a 12-
volt DC source, such as a storage
battery.
Using Standard 120-Volt AC
Power
When you use a standard 120-volt
AC power source, set the power se-
lect switch on the back of the CB to
120V AC.
Then plug the CB's AC power cord
into a standard AC outlet.
Note: The plug is polarized (one
blade is bigger than the other) so it
only fits one way. If it will not fit, turn
it over and try again. Do not force it.
Using 12-Volt DC Power
If you want to use your CB where
120-volt AC power is not available
(for example, when AC power fails or
at a remote location), you can power
your CB from 12-volt DC power. Use
the supplied DC power lead (with in-
line fuse).
Follow these steps to connect the CB
to 12-volt DC power.
1. Connect the plug end of the DC
power leads to the 13.8V DC
power jack on the back of the
CB.
2. Set the power select switch on
the back of the CB to 13.8V DC.
3. Connect the red and black
power leads to the DC power
source as follows:
• Connect the red lead (with in-
line fuse holder and fuse) to
the source’s (+) terminal.
• Connect the black lead to the
source’s negative (–) terminal.
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8
CONNECTING AN
EXTERNAL SPEAKER
You can connect an external speaker
to the EXT.SP. jack. Use an 8-ohm
speaker that has a power rating of 3
to 10 watts and a 1/8-inch plug.
Notes:
• Your local Radio Shack store
carries a full line of speakers,
including one (Cat. No. 21-549)
specifically designed for use as
an external CB speaker.
• Connecting an external speaker
silences the CB's internal
speaker.
CONNECTING
HEADPHONES
To reduce distractions or help you
hear weak signals, you can use your
CB with monaural headphones that
have a 1/4-inch plug and an imped-
ance of 4, 8, 16, or 100 ohms. Plug
the headphones' plug into the
PHONES jack on the front of your
CB.
Note: Plugging in headphones si-
lences both the internal and external
speakers.
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9
OPERATION
Caution: Do not use your CB before
you connect it to an antenna.
Before you start using your CB, you
should know how to use it effectively
and courteously. See “CB Courtesy”
and “Using 10-Codes.”
RECEIVING
TRANSMISSIONS
Note: You must connect the micro-
phone to your CB or it will not re-
ceive.
1. Set
VOLUME to MIN.
2. To turn on the CB, press
POWER to the  position. The
CHANNEL display shows the
last channel used.
3. Turn RF GAIN to HIGH (fully
clockwise).
4. Turn SQUELCH to MIN (fully
counterclockwise) so you can
hear background noise (hiss).
5. Adjust VOLUME to a comfort-
able listening level.
6. Rotate CHANNEL to the right to
increase the channel number, or
to the left to decrease the chan-
nel number. The SIGNAL meter
shows the strength of the incom-
ing signal.
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10
7. Slowly turn SQUELCH to the
right until the background hiss
disappears.
Notes:
• Do not set SQUELCH too far
to the right, or you cannot
hear weak signals.
• To receive very weak signals,
turn SQUELCH to the left.
You hear noise between
transmissions, but you also
hear weak signals (those not
strong enough to completely
break through the squelch).
8. Adjust VOLUME again to a com-
fortable listening level.
TRANSMITTING
Note: We recommend you try receiv-
ing before you begin transmitting.
1. Rotate CHANNEL to select a
channel.
2. Hold the microphone about 3
inches from your mouth. Press
and hold the microphone's talk
button and speak in a normal
voice.
The TX POWER meter shows
the strength of the transmitting
signal.
The microphone automatically
adjusts its gain to provide the
best modulation. However,
speaking very loudly or very
softly can still cause unwanted
noise or distortion.
3. Release the talk button when
you finish speaking.
4. When you are finished, turn off
the power by pressing POWER
to the m position.
USING SPECIAL
CONTROLS
Your CB features several special
controls. We suggest you learn about
these controls so you can fully enjoy
your CB.
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11
Using CH9
Important: Channel 9 is reserved for
motorist assistance and for reporting
emergency information about acci-
dents, hazardous road conditions,
and so on. Always give emergency
messages priority on Channel 9.
You can instantlyswitch to Channel 9
at any time by pressing CH9. The
display shows 9.
Note: Pressing CH9 disables CHAN-
NEL and SCAN.
To return to normal operation, press
CH9 again. Your CB returns to the
channel you were previously using.
Using SCAN
You can use the scan function to
scan for incoming signals. Press
SCAN. The TRC-495 starts to scan,
and the SCAN indicator lights.
The CHANNEL indicator shows the
scanned frequencies, then stops at
the incoming signal.
Note: If the signal is lost for about 3
seconds, the CB begins scanning
again.
Using NB and ANL
If you encounter noise while receiv-
ing, press NB (noise blanker) or ANL
(automatic noise limiter). The NB or
ANL indicator lights, and the noise
level should drop.
NB eliminates impulse-type noise
(like that produced by vehicle igni-
tions or engines).
ANL reduces the level of continuous
noise so it does not interfere with re-
ception.
If you still hear the noise, refer to
“Noise Reduction” for additional in-
formation.
If parts of the received signal sound
choppy, press NB or ANL again (to
the out position) to turn off the func-
tion.
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12
Using RF GAIN
Rotate this control to adjust your
CB's sensitivity when receiving. Nor-
mally, you will leave this control set to
HIGH. This is useful for blocking out
weak stations, while still receiving
nearby stations.
When the SIGNAL/TX POWER
meter indicates more than half scale,
it means that you are receiving a
strong signal. If the signal overloads
or distorts, rotate RFGAINto the left.
For weak signals, rotate RF GAIN to
the right.
CB COURTESY
Remember these hints when using
your CB:
• Wait for a pause in transmission
before asking for a break.
• If you do not receive an answer
after two calls to a station, let
others use the channel. Try
again later.
• Do not hold down the talk button
when you are not talking. (This
is called dead-keying.)
• Help callers with directions,
information about road condi-
tions, and any other reasonable
requests.
• Always yield any channel for
emergency transmissions.
MAXIMUM RANGE
The maximum range and quality of
CB transmissions vary depending on
these conditions:
• The type and quality of antenna
used.
• The height of the antenna's
mounting location — the higher
the antenna, the better the sig-
nal's range.
• The surrounding terrain —
mountains and tall buildings limit
the range.
• Weather conditions.
• The number of nearby CBs
operating on the same channel.
• Standing wave ratio (SWR)
between the antenna and the
CB. You can check the SWR
between the CB and a mobile or
base-station antenna using an
SWR tester (Cat. No. 21-523).
Follow the instructions supplied
with the SWR tester and the
mobile or base-station antenna
to change the SWR, if neces-
sary.
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13
USING COMMON
10-CODES
Citizen's band operators have largely
adopted the 10-codes for standard
questions and answers. These
codes permit faster communication
and better intelligibility in noisy ar-
eas. This table lists codes adopted
by the Associated Public Safety
Communications Officers (APCO).
Code Meaning
10-1 Cannot understand your
message.
10-2 Your signal is good.
10-3 Stop transmitting.
10-4 Message received and
understood.
10-5 Relay information to
____________.
10-6 I am busy or are you
busy?
10-7 Out of service.
10-8 In service.
10-9 Repeat last message.
10-10 Negative (No).
10-11 ____________inservice.
10-12 Stand by.
10-13 Report ____________
conditions.
10-14 Information.
10-15 Message delivered.
10-16 Reply to message.
10-17 En route.
10-18 Urgent.
10-19 Contact ___________.
10-20 What is your location?
10-21 Call ____________ by
telephone.
10-22 Cancel last message.
10-23 Arrived at the scene.
10-24 Assignment complete.
10-25 Meet ____________.
10-26 Estimated time of arrival
is ____________.
10-30 Use caution.
10-31 Pick up.
10-33 Emergency traffic. Clear
the channel.
10-34 What time is it?
Code Meaning
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14
TROUBLESHOOTING
If your CB is not working as it should,
refer to the following charts to see if
you can eliminate the problem. If you
cannot, take the CB to your local
Radio Shack store. DO NOT attempt
repairs or adjustments yourself.
S
y
mptom: Trouble with reception
S
y
mptom: Trouble with transmis-
sion
S
y
mptom: CB does not work at all
Check Solution
Insufficient vol-
ume? Adjust VOLUME as needed.
Too much
squelch? AdjustSQUELCH as needed.
CB not on oper-
atin
g
channel? Switch to active channel.
Microphone
connected? Connect micro- phone.
Antenna con-
nections? Secure connec- tions.
RF
g
ain too
low? Adjust RF GAIN as needed.
Channel 9
locked? Press CH9 a
g
ain.
Check Solution
Transmission
cable con-
nected to
antenna?
Secure antenna
connector.
Antenna not
fully extended? Extend to full len
g
th.
Connectors cor-
roded? Clean and ti
g
hten.
Talk button not
fully pressed? Press com- pletely. Hold
down button
while speakin
g
.
Microphone
connector
loose?
Firmly press in
jack.
Check Solution
Power con-
nected incor-
rectly?
Secure connec-
tions to a live
source.
Fuse in the DC
power lead
needs replac-
in
g
?
Replace with
identical fuse.
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15
NOISE REDUCTION
Since the receiver section of your CB
is very sensitive, it easily picks up
even the smallest signals and ampli-
fies them. Any noise that you hear
from the CB most probably originates
from external sources. The receiver
itself is exceptionally quiet.
If the noise is continuous and fairly
loud, it cannot be totally eliminated
by the automatic noise limiter (ANL)
and noise blanker (NB) circuits. You
must solve the problem at its source.
The sources of noise might be high-
voltage power lines, fluorescent
lights, electrical motors, automobile
ignition systems and so on. Also, in-
correct installation of your CB, anten-
na, or cable might cause noises.
• Try relocating your CB or
antenna away from any noise-
generating sources.
• Provide a good ground for your
antenna with UL-listed compo-
nents.
• Ensure a good shielding con-
nection in the antenna coaxial
cable. Check the connectors
and cable, and make repairs if
necessary.
• Check the routing of the antenna
cable. Reroute the cable away
from any noise-generating
sources.
In some cases, an AC line interfer-
ence filter added to the AC input of
your CB can help. If a particular ap-
pliance or motor seems to be the ma-
jor cause of noise, try to reduce or
eliminate that noise problem at the
source (the appliance or motor). You
can find many useful accessories in-
cluding AC line interference filters,
cables, and connectors at your local
Radio Shack store.
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16
CARE AND MAINTENANCE
Your TRC-495 40-Channel CB Base Station Transceiver is an example of supe-
rior design and craftsmanship. The following suggestions will help you care for
your CB so you can enjoy it for years.
Keep the CB dry. If it gets wet, wipe it dry immediately. Liquids
might contain minerals that can corrode the electronic circuits.
Handle the CB gently and carefully. Dropping it can damage cir-
cuit boards and cases and can cause the CB to work improperly.
Use and store the CB only in normal temperature environments.
Temperature extremes can shorten the life of electronic devices
and distort or melt plastic parts.
Keep the CB away from dust and dirt, which can cause premature
wear of parts.
Wipe the CB with a damp cloth occasionally to keep it looking
new. Do not use harsh chemicals, cleaning solvents, or strong de-
tergents to clean the CB.
Modifying or tampering with the CB’s internal components can cause a malfunc-
tion and might invalidate your CB’s warranty. If your CB is not performing as it
should, take it to your local Radio Shack store for assistance.
Warnin
g
: Do not open your CB to make any internal adjustments. Any internal
adjustments can be made only by an authorized Radio Shack service center.
CLEANER
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17
Internal adjustments and/or modifi-
cation can lead to illegal operation as
defined by
FCC Rules
, Part 95. Such
illegal operation can lead to very se-
rious consequences.
To be safe and sure:
• Never open your CB's case.
• Never change or replace any-
thing in your CB.
REPLACING THE FUSE
Your CB has an in-line fuse that pro-
tects the CB when you power it from
12-volts DC. If the CB does not work
when you apply power, check the
fuse. If it has blown, replace it with
one of an identical type and rating (2
Amps, Cat. No. 270-1007).
1. Grasp the ends of the fuse
holder and press in while twist-
ing both ends counterclockwise.
2. Remove the old fuse and
replace it with a new one.
3. Align the tabs on the male end
with the slots on the female end.
Then press the two ends
together and twist them both
clockwise.
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18
SPECIFICATIONS
RECEIVER
Frequency Coverage.............................................All 40 CB Channels (Class D)
26.965 to 27.405 MHz
Sensitivity.....................................................................0.7 µV for 10 dB S + N/N
Adjacent Channel Rejection.......................................................60 dB (±10 kHz)
Intermediate Frequency ........................ 1st IF = 10.695 MHz, 2nd IF = 455 KHz
Audio Output...............................................................................3.5 Watts (Max)
Frequency Response (–6 dB)......................................................... 450-2500 Hz
Squelch Sensitivity....................................................................................100
µV
TRANSMITTER
Frequency Coverage.............................................All 40 CB Channels (Class D)
26.965 to 27.405 MHz
Output Power ...........................................................................................4 Watts
Modulation Capability....................................................................................90%
Spurious Emission.....................................................................Less Than 70 dB
Frequency Tolerance................................................................................0.002%
Antenna Impedance.............................................................................. 50 Ohms
Power Requirements....120V AC, 60Hz, 50 Watts or 12 VDC, Negative Ground
Dimensions (HWD)......................215/16 x 111/8x 81/4Inches (74 x 282 x 209 mm)
Weight .........................................................................................6.6 lbs (2.3 Kg)
Specifications are typical; individual units might vary. Specifications are subject
to change and improvement without notice.
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19
NOTES
21-1579.fm Page 19 Thursday, August 5, 1999 9:34 AM

RADIO SHACK
A Division of Tandy Corporation
Fort Worth, Texas 76102
4A5 Printed in Korea
RADIO SHACK LIMITED WARRANTY
This product is warranted against defects for 90 days from date of pur-
chase from Radio Shack company-owned stores and authorized Radio
Shack franchisees and dealers. Within this period, we will repair it with-
out charge for parts and labor. Simply bring your Radio Shack sales
slip as proof of purchase date to any Radio Shack store. Warranty does
not cover transportation costs. Nor does it cover a product subjected to
misuse or accidental damage.
EXCEPT AS PROVIDED HEREIN, RADIO SHACK MAKES NO
EXPRESS WARRANTIES AND ANY IMPLIED WARRANTIES ARE LIM-
ITED IN DURATION TO THE DURATION OF THE WRITTEN LIMITED
WARRANTIES CONTAINED HEREIN. Some states do not permit limita-
tion or exclusion of implied warranties; therefore, the aforesaid limita-
tion(s) or exclusion(s) may not apply to the purchaser.
This warranty gives you specific legal rights and you may also have other rights which vary
from state to state.
We Service What We Sell
9/94
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