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20

REDUCING NOISE

Because your CB is exceptionally qui-
et, any noise you hear is probably from
an external source in your vehicle such
as the alternator, another radio or
spark plugs.

The transceiver uses an ANL (Auto-
matic Noise Limiter) circuit and a DSP
(Digital Sound Processor) circuit to re-
duce noise. However, if possible, try to
eliminate the noise by finding its
source.

You can determine the noise’s source
by turning off the engine and operating
the CB with your vehicle’s ignition set
to ACC. If the noise is reduced, the
problem is in your vehicle’s ignition or
electrical system. 

Here are a few hints to help you re-
duce or eliminate such noise:

• Make all CB power and antenna

wires as short as possible.

• Route the power wires away from

the antenna wires.

• Be sure that the chassis ground

connection is secure.

• Replace old ignition wires with

new, high-voltage, noise suppres-
sion wires.

• Install noise suppressors on your

spark plugs, or install new spark
plugs that have built-in noise sup-
pressors.

• If problems persist, check your

alternator/generator and regula-
tor gauges. You can reduce the
noise from these sources by using
bypass capacitors at the various
output voltage points. 

Your local RadioShack store has a
wide selection of noise suppression
accessories.

21-1598.fm  Page 20  Thursday, August 5, 1999  10:52 AM

Summary of Contents for TRC-498

Page 1: ...Cat No 21 1598 OWNER S MANUAL Please read before using this equipment TRC 498 40 Channel CB Mobile Transceiver with Digital Signal Processor 21 1598 fm Page 1 Thursday August 5 1999 10 52 AM...

Page 2: ...l from over modulating and distorting Automatic Noise Limiter reduces impulse type noises while receiving Large Illuminated Digital Display clearly shows the channel number Emergency Channel Switch le...

Page 3: ...unit to exceed these limitations Any adjustments to a CB radio must be made by a qualified technician using the proper test equipment To be safe and sure Never open your CB radio s case Never change...

Page 4: ...se Station 9 Operation 11 Receiving Transmissions and Adjusting Squelch 11 Transmitting 12 Using the Digital Signal Processor 13 Selecting the Emergency Channel 13 Using the PA Amplifier 14 Operationa...

Page 5: ...urface 3 Attach the holder at the mounting location using the supplied 3 mm machine screws spring washers plain washers and nuts Note If you cannot reach behind the mounting surface to attach the nuts...

Page 6: ...cannot reach behind the mounting surface to attach the nuts on the bolts use the supplied 6 mm self tapping screws and plain washers to secure the bracket 4 Attach the CB to the mounting bracket using...

Page 7: ...n SWR meter not supplied Follow the instructions supplied with the SWR meter and antenna to adjust your antenna s SWR to the lowest pos sible value SWR values of 2 0 1 are generally acceptable with re...

Page 8: ...ck on the back of the CB To an 8 ohm 3 to 10 Watt Speaker Power Connections Connecting a PA Speaker The PA speaker should have an im pedance of 8 ohms and be able to han dle at least 5 watts of power...

Page 9: ...AS A BASE STATION Although this transceiver is designed mainly for mobile use you can also use it as a base station with an AC power source For base station installation you need these items 12 volt D...

Page 10: ...se electrocution and death Call the power company to remove the antenna Do not attempt to do so yourself 2 Connect the antenna to the ANT jack on the back of the CB Black Wire to Negative Terminal of...

Page 11: ...counterclock wise 3 Turn RF GAIN fully clockwise 4 Turn on the transceiver by turning VOLUME clockwise until it clicks The channel display lights and the channel appears 5 Set OUT CH9 to OUT to select...

Page 12: ...ce background noise TR to eliminate tones hetero dynes whistles and whines 11 To turn off the CB turn VOLUME counterclockwise until you hear it click The display and indicators turn off TRANSMITTING N...

Page 13: ...tivate the DSP circuit press DSP again The DSP indicator turns off SELECTING THE EMERGENCY CHANNEL Important Channel 9 is reserved for motorist assistance and for reporting emergency information about...

Page 14: ...sceiver Then set CB PA to PA PA appears on the display 2 To transmit press the talk button on the microphone Hold the mi crophone 2 3 inches from your mouth and speak in a normal tone of voice 3 Turn...

Page 15: ...or plan a get together Ever have car trouble or run out of gas on the highway What an as surance it is to be able to radio for assistance Camping fishing and other sports are more fun with a CB radio...

Page 16: ...be tween the antenna and the CB Note Your CB radio s transmission range is generally line of sight TRANSMISSION COURTESY Please follow these guidelines of radio courtesy when using your CB Wait for a...

Page 17: ...are you busy 10 7 Out of service 10 8 In service 10 9 Repeat last message 10 10 Negative NO 10 11 _____ in service 10 12 Stand by 10 13 Report road weather condi tions 10 14 Information 10 15 Message...

Page 18: ...rouble receiving Turn transceiver power on Microphone connected Secure connections Antenna connected Secure connections Too much squelch Adjust as needed Radio not on operating channel Switch to activ...

Page 19: ...he Fuse on Page 22 Cannot select a channel Set CB PA to CB Set OUT CH9 to OUT Talk button fully pressed in Press completely PA does not work Connect a PA speaker Secure connections Set CB PA to PA Adj...

Page 20: ...nition or electrical system Here are a few hints to help you re duce or eliminate such noise Make all CB power and antenna wires as short as possible Route the power wires away from the antenna wires...

Page 21: ...normal temperature environments Temper ature extremes can shorten the life of electronic devices damage batteries and distort or melt plastic parts Keep the CB away from dust and dirt which can cause...

Page 22: ...Make sure the power source and CB are both off 2 Hold the fuse holder by both ends push the ends together twist one end counterclockwise then pull them apart 3 Remove the old fuse and inspect its con...

Page 23: ...sponse for 450 2500 Hz 6 dB Microphone Sensitivity for 50 Modulation 1 mV PUBLIC ADDRESS AMPLIFIER Maximum Output Power 6 Watts Microphone Sensitivity for 4 Watts Output Power 3 mV Frequency Response...

Page 24: ...e War ranty does not cover transportation costs Nor does it cover a product subjected to mis use or accidental damage EXCEPT AS PROVIDED HEREIN RadioShack MAKES NO EXPRESS WARRANTIES AND ANY IMPLIED W...

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