Sony XR-1790 User manual

1999 by Sony Corporation
Operating Instructions US
3-865-584-11 (1)
FM/AM
Cassette Car
Stereo
XR-1790
For installation and connections, see the supplied installation/connections
manual.
Owner’s Record
The model and serial numbers are located on the bottom of the unit.
Record the serial number in the space provided below.
Refer to these numbers whenever you call upon your Sony dealer regarding this
product.
Model No. XR-1790 Serial No.

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Welcome!
Thank you for purchasing the Sony Cassette
Car Stereo. This unit lets you enjoy a variety of
features.
Features
General
•Built-in power amplifier (max. output:
35 W ×4 ch) enables you to enjoy a
4-speaker system.
•Digital 12-hour clock provided (page 5).
Cassette player section
ATA (Automatic Tuner Activation) for
automatically turning on the tuner while fast-
forwarding or rewinding a tape (page 6).
Tuner section
•Up to 18 stations can be preset: 12 stations on
FM and 6 stations on AM.
•Automatic memory function stores a total
of 18 stations in memory quickly and easily
(page 7).
Warning
This equipment has been tested and found to
comply with the limits for a Class B digital
device, pursuant to Part 15 of the FCC Rules.
These limits are designed to provide
reasonable protection against harmful
interference in a residential installation. This
equipment generates, uses, and can radiate
radio frequency energy and, if not installed
and used in accordance with the instructions,
may cause harmful interference to radio
communications. However, there is no
guarantee that interference will not occur in a
particular installation. If this equipment does
cause harmful interference to radio or
television reception, which can be determined
by turning the equipment off and on, the user
is encouraged to try to correct the interference
by one or more of the following measures:
— Reorient or relocate the receiving antenna.
— Increase the separation between the
equipment and receiver.
— Connect the equipment into an outlet on a
circuit different from that to which the
receiver is connected.
— Consult the dealer or an experienced radio/
TV technician for help.
You are cautioned that any changes or
modifications not expressly approved in this
manual could void your authority to operate
this equipment.

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Table of Contents
Location of controls ............................................ 4
Getting Started
Setting the clock .................................................. 5
Cassette Player
Listening to a tape ............................................... 6
Ejecting the cassette ............................................ 6
Fast-winding the tape ......................................... 6
Radio reception during fast-forwarding or
rewinding of a tape
— ATA (Automatic Tuner Activation)
function ........................................................... 6
Radio
Searching for stations automatically
— Automatic tuning...................................... 7
Tuning in by adjusting the frequency
— Manual tuning........................................... 7
Memorizing stations automatically
— Automatic memory function................... 7
Memorizing only the desired stations ............. 8
Receiving the memorized stations.................... 8
Other Functions
Adjusting the sound characteristics ................. 8
Enjoying bass and treble at low volume
— Loudness Function ................................... 8
Attenuating the beep tone ................................. 8
Additional Information
Precautions........................................................... 9
Maintenance....................................................... 10
Dismounting the unit ....................................... 11
Specifications ..................................................... 12
Troubleshooting guide ..................................... 13

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Location of controls
7LCL (local seek) button 7
8(volume/bass/treble/
balance/fader control) buttons 5, 8
9SEEK/MANU button 7
!º LOUD (loudness) button 8
!¡ TUNER/A MEM (radio on •band select/
automatic memory) button 7, 8
!™ OFF button
Refer to the pages for further details.
1Display window
2SEL (control mode select) button 5, 8
3DSPL (display mode change/time set)
button 5
46(eject) button 6
5During radio reception:
Preset number buttons 8
During tape playback:
ATA
1
ATA (Automatic Tuner
Activation) button 6
60/)(fast winding)/DIR (tape
transport direction change) buttons 6
DSPL ATA
SEEK
MANU
LCL
A MEM
DIR
213 64 5
XR-1790
SEL TUNER OFFLOUD

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Getting Started
The clock activates.
4Press the
DSPL
button momentarily.
Note
The clock cannot be set unless the power is turned
on. Set the clock after you turn on the radio, or
during tape playback.
Getting Started
Setting the clock
The clock has a 12-hour digital indication.
For example, setting it to 10:08
1Display the time.
(Press the
DSPL
button during unit
operation.)
2Press the DSPL button for more than two
seconds.
Set the hour digits.
3Press the
SEL
button momentarily.
Set the minute digits.
(to go back) (to go forward)
(to go back) (to go forward)
The hour digit blinks.
The minute digits blink.

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Direction
indicator*
(
9
To advance To rewind
To resume playback, press the other fast-
winding button partially until the locked
button is released.
*The 9or (indicator will flash while fast-
winding the tape.
Radio reception during
fast-forwarding or
rewinding of a tape
— ATA (Automatic Tuner Activation) function
Press the
ATA
1
button during playback.
n“ATA” appears on the display.
When fast-forwarding or rewinding with the
0or )button, the tuner will turn on
automatically.
Fast-winding the tape
Cassette Player
Listening to a tape
After inserting the cassette, playback
will start automatically.
To change the tape direction,
press both the 0and the )buttons at the
same time.
Indication of tape transport direction
The side facing up is being played.
The side facing down is being played.
At the end of the tape, the playing direction
will change automatically.
Note
Before turning off the unit, eject the tape to avoid
tape damage.
Ejecting the cassette
Press the button to stop playback and eject
the cassette.

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Tuning in by adjusting the
frequency— Manual tuning
1Select the desired band.
2Press and hold either side of the SEEK/
MANU button.
Release the button when the desired station
is received.
PREVENT ACCIDENTS!
While driving, use the automatic tuning and
the memory preset tuning instead of the
manual tuning.
Memorizing stations
automatically
— Automatic memory function
Stations with the clearest reception are
automatically searched and memorized on
each band (FM1, FM2 and AM). Up to 6
stations on each band can be stored on the
preset number buttons 1 to 6 in the order of
band frequency.
1Select the desired band.
2Press the TUNER/A MEM button for more
than two seconds.
The unit will start scanning the selected
band and automatically memorize the
tuned stations on the preset number button
1 through 6.
For lower
frequencies
Cassette Player/Radio
FM1 nFM2 nAM nFM1
FM1 nFM2 nAM nFM1
For higher
frequencies
Radio
Searching for stations
automatically
— Automatic tuning
1Select the desired band.
2Press either side of the SEEK/MANU
button momentarily to search for the
next station (automatic tuning).
The scanning stops when a station is received.
Press either side of the button repeatedly until
the desired station is received.
When an FM stereo program with a sufficient
signal strength is tuned in,
To avoid the automatic tuning from stopping on
stations too frequently, press the LCL button
momentarily to get the “LCL” indication (local
seek mode).
Only the stations with relatively strong signals will
be tuned in. The local seek mode functions only
when the automatic tuning is in operation.
the “ST” indication will appear.
FM1 nFM2 nAM nFM1
For lower
frequencies For higher frequencies
TUNER
A MEM
SEEK
MANU
SEEK
MANU
ST
TUNER
A MEM
SEEK
MANU
SEEK
MANU
TUNER
A MEM
TUNER
A MEM

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Other Functions
Adjusting the sound
characteristics
1Select the item you want to adjust by
pressing the
SEL
button repeatedly.
VOL (volume) nBAS (bass) nTRE
(treble) nBAL (balance) nFAD (fader)
nVOL (volume)
2Adjust the selected item by pressing
either the or button.
Adjust within three seconds after selecting.
(After three seconds the button will again
serve as volume control button.)
Enjoying bass and treble
at low volume
— Loudness Function
Press the
LOUD
button. n“LOUD” will
appear on the display.
Bass and treble will be boosted. To cancel,
press again.
Attenuating the beep
tone
Press the
5
button while pressing
the
SEL
button.
To reactivate the beep tone, press these buttons
once more.
Memorizing only the
desired stations
1Select the desired band.
2Tune in the station which you wish to
store on the preset number button.
3Press and hold the desired preset
number button (
ATA
1
to
6
) for about
two seconds until you hear a beep tone.
The number of the pressed preset number
button appears in the display window.
Up to 6 stations on each band (FM1, FM2 and AM)
can be stored on the preset number buttons in the
order of your choice. Therefore, 12 stations can be
memorized on FM.
If you try to store another station on the same
preset number button, the previously stored
station will be erased.
Receiving the memorized
stations
1Select the desired band.
2Press momentarily the preset number
button on which the desired station is
stored.
Note
If you press the preset number button for more
than two seconds, the currently received station
will be memorized. To receive the previously
memorized station, make sure that the preset
number button is pressed only momentarily.
FM
ST
FM1 nFM2 nAM nFM1
FM1 nFM2 nAM nFM1
TUNER
A MEM
TUNER
A MEM

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Radio/Other Functions/Additional Information
Additional
Information
Precautions
•If your car was parked in direct sunlight
resulting in a considerable rise in
temperature inside the car, allow the unit to
cool off before operating it.
•If no power is being supplied to the unit,
check the connections first. If everything is in
order, check the fuse.
•If no sound comes from the speakers of a
2-speaker system, set the fader control to the
center position.
•If your car is equipped with a power
antenna, note that it will be automatically
extended while the unit is operating.
If you have any questions or problems
concerning your unit that are not covered in
this manual, please consult your nearest Sony
dealer.
To maintain high quality sound
If you have drink holders near your audio
equipment, be careful not to splash juice or
other soft drinks onto the car audio. Sugary
residues on this unit or cassette tapes may
contaminate the playback heads, reduce the
sound quality, or prevent sound reproduction
altogether.
Cassette cleaning kits cannot remove sugar
from the tape heads.
Notes on cassettes
Cassette care
•Do not touch the tape surface of a cassette, as
any dirt or dust will contaminate the heads.
•Keep cassettes away from equipment with
built-in magnets such as speakers and
amplifiers, as erasure or distortion on the
recorded tape could occur.
•Do not expose cassettes to direct sunlight,
extremely cold temperatures or moisture.
•When the tape is played back for a long
period, the cassette may become warm
because of the built-in power amplifier. This
is not a sign of a malfunction.
•Slack in the tape may cause the tape to be
caught in the machine. Before you insert the
tape, use a pencil or similar object to turn the
reel and take up any slack.
•Distorted cassettes and loose labels can cause
problems when inserting or ejecting tapes.
Remove or replace loose labels.
Notes on cassette deck tape heads
•Long use of cassette tapes contaminates the
tape head causing poor sound quality or
complete sound dropout. Therefore, we
recommend cleaning the tape head once a
month or so with the separately available
Sony Cassette Cleaning Set. If the sound does
not improve after using a cleaning cassette,
please consult your nearest Sony dealer.
•In case of old or inferior cassette tapes, the
tape head gets contaminated much more
quickly. Depending on the tape, one or two
playbacks may cause poor sound.
Slack

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Maintenance
Fuse replacement
When replacing the fuse, be sure to use one
matching the amperage rating stated on the
fuse. If the fuse blows, check the power
connection and replace the fuse. If the fuse
blows again after replacement, there may be an
internal malfunction. In such a case, consult
your nearest Sony dealer.
Warning
Never use a fuse with an amperage rating
exceeding the one supplied with the unit as
this could damage the unit.
Cassettes longer than 90 minutes
The use of cassettes longer than 90 minutes is
not recommended except for long continuous
play. The tapes used for these cassettes are
very thin and tend to be stretched easily.
Frequent playing and stopping of these tapes
may cause them to be pulled into the cassette
deck mechanism.
Fuse (10 A)

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Dismounting the unit
1Insert the supplied tool between the unit
and the frame, and rotate 90° to release
the hidden mounting spring. Repeat on
the opposite side and remove the frame.
2Insert a flathead screwdriver between
the bracket and mounting spring. Gently
pry the spring toward the unit while
pulling the unit out a little. Repeat on
the opposite side and remove the unit.
Additional Information
90°
10 mm (13/32 in.)
4 mm (3/16 in.)

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Cassette player section
Tape track 4-track 2-channel stereo
Wow and flutter 0.13 % (WRMS)
Frequency response 30 – 15,000 Hz
Signal-to- noise ratio 55 dB
Tuner section
FM
Tuning range 87.5 – 107.9 MHz
Antenna terminal External antenna connector
Intermediate frequency 10.7 MHz
Usable sensitivity 9 dBf
Selectivity 75 dB at 400 kHz
Signal-to-noise ratio 65 dB (stereo),
68 dB (mono)
Harmonic distortion at 1 kHz
0.7% (stereo),
0.4% (mono)
Separation 35 dB at 1 kHz
Frequency response 30 – 15,000 Hz
AM
Tuning range 530 – 1,710 kHz
Antenna terminal External antenna connector
Intermediate frequency 450 kHz
Sensitivity 30 µV
Power amplifier section
Outputs Speaker outputs
(sure seal connectors)
Speaker impedance 4 – 8 ohms
Maximum power output 35 W ×4 (at 4 ohms)
General
Output lead Power antenna relay
control lead
Tone controls Bass ±8 dB at 100 Hz
Treble ±8 dB at 10 kHz
Power requirements 12 V DC car battery
(negative ground)
Dimensions Approx. 186 ×57 ×176 mm
(7 3/8×2 1/4×7 in.)
(w/h/d) not incl.
projecting parts and
controls
Mounting dimension Approx. 182 ×53 ×163 mm
(7 1/4×2 1/8×6 1/2in.)
(w/h/d) not incl.
projecting parts and
controls
Mass Approx. 1.2 kg (2 lb. 10 oz.)
Supplied accessories Parts for installation and
connections (1 set)
Design and specifications are subject to change
without notice.
Specifications
AUDIO POWER SPECIFICATIONS
POWER OUTPUT AND TOTAL HARMONIC DISTORTION
13 watts per channel minimum continuous average power into
4 ohms, 4 channels driven from 20 Hz to 20 kHz with no more than
1% total harmonic distortion.

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Troubleshooting guide
The following checklist will assist in the correction of most problems which you may encounter with
your unit.
Before going through the checklist below, refer to the connection and operating procedures.
General
Cause/Solution
•Adjust the volume with the button.
•Set the fader control to the center position for 2-speaker
systems.
Remove the front panel and clean the connectors. See “Cleaning
the Connectors” of “Maintenance” for details.
Problem
No sound
Indications do not appear in the
display window.
Tape playback
Problem
The sound is distorted.
Cause/Solution
Contamination of the tape head. nClean the head.
Radio reception
Problem
Preset tuning is not possible.
Automatic tuning is not possible.
Cause/Solution
•Memorize the correct frequency.
•The broadcast is too weak.
The broadcast is too weak. nUse the manual tuning.
Additional Information

Sony Corporation Printed in Malaysia