ASV 3270 User manual

ASV 3270
Automotive Audio Tester
User Manual
airsoundvision.com

The ASV 3270 is a multi-tester for use during car audiovisual system
installation.
It has 5 different modes of operation.
1 - Voltage Detection. Quickly determine if a wire has 12V or 24V
on it. This function works much like a traditional test light, except
that it has a high impedance input to minimise the risk of damage to
the electronics in modern vehicles, and it can differentiate between
12V and 24V.
2 - Line Audio Listen. Using its miniature inbuilt speaker and
amplifier, this mode allows the installer to test a line level output
from a head unit or sound processor for a signal.
3 - Line level Tone Generator. In this mode, the ASV 3270 outputs
a test tone at line level that can be used to check amplifiers.
4 - Speaker Polarity (Phase) Test. By playing a special test tone on
the head unit and connecting the 3270 to speaker wires, the installer
can instantly determine which wire is positive and which negative.
5 - Speaker Test. The speaker test mode allows the installer to
quickly test if a speaker works. It also pulses the speaker with a
200mA current every couple of seconds, which displaces the cone,
allowing polarity to be determined. This mode also gives an
approximate indication if the speaker is a 2 Ohm or 4 to 8 Ohm
impedance, and can allow the installer to quickly determine if there
is a short circuit in speaker wiring.
CAUTION
The ASV 3270 is rated to a maximum voltage of
32VDC. Connecting to voltages higher than this
may risk damage to the unit and injury to the
operator.
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On Line
The latest version of this manual, polarity test tone MP3 file, and
instructional videos can be found on our web site:
http://airsoundvision.com/asv3270

Basic Operation
The ASV 3270 takes a 9V alkaline battery, which must be fitted
in the battery compartment on the rear of the device.
Switch on the ASV 3270 by briefly pressing the Mode button.
The 4 mode LEDs will light while the button is depressed,
indicating battery condition. When the button is released, the
ASV 3270 will be in voltage test mode.
Each further press on the Mode button will cycle through the
modes in this order.
To switch the ASV 3270 off, hold the Mode button down for
more than 3 seconds until the LEDs switch off.
Auto Power Off
If the Mode button on the ASV 3270 is not operated for more
than approximately 5 minutes, it will switch itself off to conserve
the battery.
Disabling Auto Power Off
It is possible to temporarily disable the Auto Power Off function
by holding down the Mode button for 10 seconds when
switching on the ASV 3270. All the LEDs will flash several times
to indicate that the Auto Power Off function has been disabled.
This will be reset back to normal when the unit next is switched
off. Remember to manually switch off the ASV 3270 when you
are finished with it.
Low Battery
When the battery voltage is too low for proper operation the 4th
mode LED will start flashing and the ASV 3270 will no longer be
functional until the battery is replaced.
Voltage Test Audio Listen Audio Tone
Speaker Test Polarity Test
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Detailed Operation
Mode 1
Voltage Test Mode
Connect the black lead to ground and the red lead to a wire you
want to test for the presence of voltage.
If the voltage on the red lead is between approximately 11 and
16 volts, LED A will light, indicating a nominal 12V. If the wire is
between approximately 16 and 28 volts LED B will light,
indicating a nominal 24V.
To find a wire with ground on it, connect the red lead to a known
source or 12V (or 24V) and probe the wire of interest with the
black lead.
CAUTION: In order to minimise the risk of damage to the
electronic equipment found in modern cars, the ASV 3270's
input impedance in voltage test mode is quite high
(approximately 48000 Ohms).
This means the installer needs to be aware that reading a
voltage (or ground) does not give any indication whether the
wire can carry any current or not.
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Mode 2
Line Level Listen.
Using a 3.5mm to RCA lead,
connect the ASV 3270 to the
output of a head unit or signal
processor.
The built in amplifier and
miniature speaker will give an
indication of the presence of
audio.
NOTE: Standard line-level signals will be very quiet. You may
need to turn the volume on the head unit up to maximum.
Tip: Connecting to a video source will produce a buzz,
indicating the presence of a video signal.
Mode 3
Line Output Tone.
Using a 3.5mm to RCA lead,
connect the ASV 3270 to the
input of an amplifier you want to
test. In this mode, the ASV 3270
outputs a nominal line level
signal.
CAUTION: Make sure the gain
of the amplifier under test is set
low to start with when testing to
prevent speaker or ear damage
due to the loud tone.
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Mode 4
Polarity Test
The polarity test mode is useful
to test an unknown pair of
speaker wires for the correct
phasing.
A special polarity test tone is required in order for this mode to
work.
This tone can be downloaded from
http://airsoundvision.com/asv3270
On this page is an MP3 file for copying to a USB flash drive or
data CD. You can also use Windows Media Player or third party
software to create an Audio CD from this file.
Once you have downloaded the file and created the required
media, start playing the file in the head unit at a moderate
volume.
Connect the ASV 3270 to a pair of speaker wires. If LED A
lights, the speaker wire connected to the red test lead is
positive.
NOTE 1: Some equipment will introduce phase reversal over
the entire system. This is not a problem except all speaker
wires will read as reversed.
NOTE 2: Setting the volume too high or too low may produce a
false reading.

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Mode 5 - Speaker Test
In speaker test mode, the ASV 3270 produced a tone with
pulsed DC current at 200mA to enable testing of speakers.
CAUTION: Do not probe random wires while in this mode.
The ASV 3270 outputs 200mA of current at up to 9V, which
may damage some of the sensitive circuits in a modern
vehicle.
The most common use for this mode is in determining which
wires at a head unit run to
which speakers.
Simply connect the ASV 3270
to a pair of speaker wires while
in speaker test mode and a
tone will be heard from the
speaker.
Approximately every 2
seconds, the tone will change
as a DC pulse is introduced.
Use this pulse to check the
polarity of the speaker by
feeling for movement of the speaker cone. If the red wire is
connected to the positive speaker wire, the cone will move
outwards during the pulse, otherwise it will move inwards.
Speaker test mode is also very handy to check that no speaker
wires are shorted to ground: Connect the black lead to ground
and the red lead to one of the speaker wires. If either A or B (or
both) LEDs light up, or the tone is heard from the speaker, a
short circuit to ground is present.
NOTE: A false reading may be given if the speaker wires are
connected to the output of a head unit or amplifier.
The LEDs will also give an indication of the impedance of the
speaker under test, but because this is done by measuring the
DC resistance, it may not always be completely accurate.

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Testing Battery Condition
When switching on the ASV
3270, the 4 mode LEDs give
an indication of battery status
while the Mode button is
depressed.
If all 4 LEDs illuminate, there is plenty of charge remaining.
The number of LEDs will decrease according to the remaining
capacity.
If the battery is too low to properly operate the unit, the Empty
LED will flash.

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ASV 3270 - Specifications (at 10 ~ 32°C)
Voltage Test Mode
Input Impedance: 48KOhms +/-5%
Maximum Input voltage: 32VDC
Measurement Accuracy: +/- 5%
Line Listen Mode
Input Impedance: 48KOhm +/- 5%
Line Output Mode:
Output Impedance: 48KOhm +/- 5%
Output Level (50KOhm Load): 300mV p-p +/-10%
Output Frequency: 260Hz +/-10%
Polarity Test Mode
Input Impedance: 95KOhm +/- 5%
Test Tone: 200Hz Pulse @ 75% Duty Cycle
Minimum Valid Signal Level: 900mV p-p +/-10%
Maximum Valid Signal Level: 20V p-p +/- 10%
Speaker Test Mode
Maximum Output Voltage: 9V p-p
Maximum Output Current: 250mA (Nominal 200mA)
Short Circuit Range: 0 ~ 1.5Ohms +/-5%
2 Ohm Range: 1.5 ~ 3Ohms +/- 5%
4-8 Ohm Range: 3 ~ 9Ohms +/- 5%
Output Frequency: 220Hz +/-10%
Battery Type: 9V Alkaline
Battery Working Voltage Range: 5.5 ~ 10VDC
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A PDF file of this manual can be downloaded from:
http://airsoundvision.com/asv3270

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