Altronics Redback Q 2001 User manual

BL2074
Q 2001
Impedance Meter
®
www.altronics.com.au
Features:
• 16 x 2 LCD shows impedance, 100V and 70V load value.
• 1Ωto 19KΩtest range
• Single push button operation.
• Auto ranging.
• Inbuilt Battery charger circuit.
• Display accuracy +/-10%.
• Low battery indication.
• Rugged yet easy to hold hand held case.
• Easy battery replacement.
• System test mode.
Introduction:
Measuring a transformer with a regular ohm meter or multimeter
is very difficult and provides inaccurate results. This is because
an ohm meter or multimeter uses DC to measure the resis-
tance. Consider a transformer, which is basically a coil of wire,
the DC resistance will be fairly low. If an AC signal is passed
through the winding the impedance will be much higher, unless
the winding is shorted. In this case the reading will be very low.
In the case of a short circuit the inductance of the transformer
tries to impede the current flow through the winding. The nature
of transformers will result in the impedance being reflected into
other windings on the transformer being tested. This means a
shorted turn on any winding will show up on the other windings.
An impedance meter is also critical for accurately measuring
low impedance loudspeaker systems, incorporating multiple
speakers and crossovers, and for measuring commercial 100V
line speaker systems, which may include many speakers with
line transformers and several hundred meters of cable. Trying
to measure this type of load is virtually impossible with a stan-
dard multimeter.
For example a short circuit on several hundred metres of cable
will not show up as a short circuit on a standard multimeter .
You will actually measure the DC resistance of the cable which
will be around 22 ohms for 500 meters of 24/0.2 cable.
Using an impedance meter, measuring the AC resistance will
read a short circuit. A short circuit located remotely in a speaker
line is the major cause for amplifiers overheating and blowing
DC fuses.
Shorted turns on mains transformers primary windings can also
be measured with this meter. If this meter displays a value of
less than 100 ohms, this will indicate that the transformer has a
shorted turn.
Operation
TO MEASURE IMPEDANCE
Make sure the amplifier has been completely disconnected from
the line to be measured.
Connect the test leads to the Q 2001
Connect the test leads to the speaker line.
Once your meter is connected press the TEST button for
approximately 1 second, the impedance meter will display
"CHECKING LOAD" for approximately 3 seconds while it
checks the speaker load. You will be able to hear a tone from
the speaker load that is under test. After 3 seconds the load
impedance will be displayed on the LCD along with the 100V
load value. After 8 seconds the 70V load value will replace the
100V load value on the LCD.
Operating Instructions

REDBACK Q 2001
Page 2 BL2074
SYSTEM CHECK MODE
System check Mode is included for audible testing of larger
speaker installations. It allows the Q 2001 to run at full output
for a period of approximately 6 minutes so the installer can walk
around the install to check sound is present on all speakers.
To activate this mode connect the test leads to the load to be
checked, ensure that an amplifier is not connected. Make sure
the Q 2001 is OFF then press the TEST button and hold for 2 to
3 seconds “SYSTEM CHECK” will display on the LCD and a
1kHz tone will be put out the test leads.
SWITCHING OFF
To switch off the The Q 2001 all you need to do is press the
TEST button again. The LCD will display “OFF” for a short time
then the unit will power down. The Q 2001 is also equipped with
an auto power off function. The unit will automatically power
down after a period of 20 seconds in Single test mode and 6
minutes in System check mode, saving precious battery life.
BATTERY INSTALLATION AND OR CHARGING.
“LOW BATTERY” will display on the LCD when the battery
requires replacing or if a rechargeable 9V Nicad/Nimh battery
needs charging (not supplied).
To replace or install the 9V (type 216) battery required to power
the Impedance Meter, simply slide off the battery compartment
on the back of the unit. Remove and unclip the old battery from
the connector and replace it with a fresh battery. Slide the cover
back until it locks into place.
To recharge an installed Nicad/Nimh battery connect a 12VDC
source (car battery, cigarette lighter socket or plug pack)
>300mA with a 2.1mm centre positive plug to the Charging
socket located on the top of the Q 2001. "CHARGING" will dis-
play on the LCD along with the charge %. When the charge %
reaches 100% the Q 2001 will stop charging and display
"CHARGE FINISHED" on the LCD. The charger can then be
unplugged. The inbuilt charging circuit is a slow charger and will
take up to 12 hours to charge a completely flat battery.
NOTE:
1) The Q 2001 will not function as an Impedance meter when
charging.
2) The charger can be removed at anytime during charging
though battery life will suffer.
3) The Q 2001 will still function when “LOW BATTERY” is being
shown on the LCD but the measured results may be out by as
much as 10%.
IMPORTANT GUIDELINES:
Don't connect the meter to a line that has an amplifier
attached to it. The impedance of the output transformer of
an amplifier is extremely low and you could be easily be
looking for a non-existing short.
Don't connect the meter to an active line. You will damage
the meter with the applied voltage.
Don't continue to use a battery once the “LOW BATTERY”
is being shown on the LCD. The readings you will get will
be incorrect.
Manufactured in Australia by Altronic Distributors Pty. Ltd. Perth. Western Australia.
Phone: [phone] Fax: [phone] Internet: www.altronics.com.au