background image

17

MAXIMUM RANGE

The maximum range and quality of CB
transmissions vary depending on the fol-
lowing typical conditions:

• The type and quality of antenna

used.

• The height of the antenna's mount-

ing location — the higher the
antenna, the greater the signal's
range

• The surrounding terrain — moun-

tains and tall buildings limit the
range.

• Weather conditions.

• The number of nearby CBs operat-

ing on the same channel.

REDUCING NOISE

The audio clarity enhancer (ACE) circuit
uses compander (compressor and ex-
pander) technology to improve commu-
nication quality. The circuit maintains
the dynamic range while increasing the
signal-to-noise ratio as the gain is auto-
matically controlled according to the in-
put signal level. This results in a
reduction in wide band noise.

The noise blanking (NB) circuit helps
keep background noise to a minimum.
However, strong sources of electrical
noise, generated by spark plugs or the
ignition of your car, or another radio,
might be more than the circuit can com-
pensate for.

If you suspect engine noise as a source,
turn off the engine and operate the CB
with the ignition set to ACC. If most or all
of the noise stops, the problem is in ve-
hicle's ignition or electrical system.

The following few hints can help you re-
duce or eliminate such noise.

• Replace old ignition wires with new,

high-voltage, noise-suppression
wires.

• Install noise suppressors on your

spark plugs, or install new spark
plugs that have built-in suppressors.

• Be sure that the black wire ground

connection is securely attached to
either your vehicle’s battery's nega-
tive (GND) terminal or to a good
electrical chassis ground.

If problems persist, check your alterna-
tor or generator, voltage regulator, and
any stand-alone gauges. Noise from
these sources can be reduced or elimi-
nated using bypass capacitors at vari-
ous output voltage points.

Your local RadioShack store has a wide
selection of noise-suppression accesso-
ries.

21-1574.fm  Page 17  Thursday, May 13, 1999  4:03 PM

Содержание TRC-446

Страница 1: ...Cat No 21 1574 OWNER S MANUAL Please read before using this equipment TRC 446 Deluxe 4 Watt 40 Channel Mobile CB Radio with Weather Alert and ACE 21 1574 fm Page 1 Thursday May 13 1999 4 03 PM...

Страница 2: ...weather alert Built In SWR Meter helps you tune your antenna system to optimize your CB s performance RF Gain Control lets you adjust re ception to match the strength of the re ceived signal Convenien...

Страница 3: ...sion FCC does not require you to have a license to operate this CB However the FCC does require that you read and know Part 95 of FCC Rules These rules apply to the operation of a Class D CB We have p...

Страница 4: ...the Standing Wave Ratio 9 Standing Wave Ratio Guidelines 10 Standing Wave Ratio Performance 10 A Quick Look at the Controls 11 Operation 12 Changing Channels Using the Controls on the Microphone 13 L...

Страница 5: ...46 in a vehicle mount it securely to avoid damage to the CB or vehicle or injury to any one in the vehicle during sudden starts or stops Do not mount the CB where it could damage or interfere with the...

Страница 6: ...the plug s locking nut clockwise 3 Slide the microphone onto the microphone holder To disconnect the microphone unscrew the locking nut and gently pull out the microphone plug Caution Always grasp th...

Страница 7: ...eas that produce extreme heat USING VEHICLE BATTERY POWER You can power this CB from your vehi cle s battery or from standard AC power with an optional DC power supply For in formation on using AC pow...

Страница 8: ...to remove the antenna DO NOT attempt to do so yourself 2 Route the antenna cable to the CB then connect the cable to ANTENNA on the back of the CB 3 Plug the single connector end of the power cord int...

Страница 9: ...teps to adjust the standing wave ratio Note The SWR on some mobile and base station antennas cannot be changed 1 Turn on the CB by turning OFF VOL UME clockwise until it clicks 2 Set S RF SWR CAL to C...

Страница 10: ...rade with a subsequent rise in the SWR Anytime you notice that the SWR reading is greater than 3 1 check the condi tion of the antenna the antenna cable and all antenna connectors and hardware Ratio R...

Страница 11: ...brate Switch CB Weather Alert Pub lic Address Switch Noise Blanking On Off Switch Audio Clarity Enhancer On Off Switch Channel Display Transmit Receive Indicator Weather Alert Indicator Squelch Contro...

Страница 12: ...ly tune channels turn the tuning control beneath the display to select a channel The selected channel number appears and the SWR RF Signal Meter shows the signal strength To quickly tune to Channel 9...

Страница 13: ...of your transmis sion Note Do not speak too loudly when transmitting It does not make your signal any stronger and might dis tort your transmission 3 When you finish transmitting release the microphon...

Страница 14: ...ceives this signal tone WX ALERT lights orange regardless of the position of CB WX PA NOAA transmits this tone for 5 to 10 seconds If the TRC 446 is set to CB or PA the orange light remains on even af...

Страница 15: ...in traffic or that you will stop by the store on the way home If you are a two or more car family CBs are great for inter car communi cations while family members are going places Contact friends or...

Страница 16: ...eived and under stood 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 ____________in service 10 12...

Страница 17: ...ed by spark plugs or the ignition of your car or another radio might be more than the circuit can com pensate for If you suspect engine noise as a source turn off the engine and operate the CB with th...

Страница 18: ...A on the rear of the radio and attached securely to the antenna at the other end Transmission difficulties The CB is turned on OFF VOLUME is at a sufficient listening level The microphone is securely...

Страница 19: ...stort or melt plastic parts Keep the CB away from dust and dirt which can cause premature wear of parts Handle the CB gently and carefully Dropping it can damage circuit boards and cases and can cause...

Страница 20: ...at No 270 1005 Follow these steps to replace each fuse 1 Make sure the power source and CB are both off 2 To open the fuse holder push the fuse holder ends together then turn either end counterclockwi...

Страница 21: ...Output 4 5 Watts Maximum Frequency Response 450 2500 Hz Intermediate Frequency 1st IF 10 695 MHz 2nd IF 455 KHz Cross Modulation 50 dB Squelch Adjustable from 0 5 V to 1 mV TRANSMITTER Output Power 4...

Страница 22: ...wer 1 2 Amps WEATHER RADIO Frequency Coverage MHz 162 400 162 425 162 450 162 475 162 500 162 525 162 550 Specifications are typical individual units might vary Specifications are subject to change an...

Страница 23: ...23 NOTES 21 1574 fm Page 23 Thursday May 13 1999 4 03 PM...

Страница 24: ...during the warranty period take the product and the RadioShack sales receipt as proof of purchase date to any RadioShack store RadioShack will at its option un less otherwise provided by law a correc...

Отзывы: