Signet PDA500, PDA1000 Operation & Instruction Manual
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Doc No. DCP0000518 JH 12/7/99 rev2
Features Technical Description
• PDA500 provides up to 250m
2
coverage
• PDA1000 provides up to 550m
2
coverage
• Automatic tracking compressor
• Line input
• Mic input
• Hidden controls
• Popular 3pin XLR connectors
• Input peak LED
• Output current meter
• 19” rack mounting case
Operation Instruction Manual
PDA500 & PDA1000
Audio frequency induction
loop ampilifiers
The PDA series are constant current audio
frequency induction loop amplifiers. They use an
advanced and unique floating sense system to
achieve greater efficiency and to correct the
phase problems created by driving an inductor,
whilst also providing exceptional sound quality
The pre amplification stage in the PDA
series incorporates an advanced signal processing system which allows tight control to be maintained over the signal. This is achieved with only
minimal degradation of the signal and is unnoticeable in normal operation. This is far more
advanced and sophisticated system than that
found in many dedicated signal processing units.
The processor can be switched between
compression and compansion (compression and
expansion). Expansion is limited to 28 dB to
prevent background noise and hiss being amplified. Compression up to 90dB is available. The
compression ratio is dynamically variable. For
most applications the processor should be set
for compression, however compansion should
be used in installations where there are a large
number of microphones and little or no external
signal processing.
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Doc No. DCP0000518 JH 12/7/99 rev2
AC power operation
For normal AC operation, plug the AC power
supply cord in a wall outlet of 230 V specified
voltage. The unit complies with BS415.
AC power cord
The wires in the mains lead supplied with the
unit are coloured in accordance with the following code.
Green and Yellow Earth
Blue Neutral
Brown Live
As the colours of the wires in the mains lead of
this unit may not correspond with the coloured
markings identifying the terminals in your plug,
please connect as follows.
Wire Plug terminal
Green & Yellow ‘E’ mark
‘EARTH’ symbol mark
‘GREEN’ mark
‘GREEN AND YELLOW’ mark
Blue ‘N’ mark
‘BLACK’ mark
‘BLUE’ mark
Brown ‘L’ mark
‘RED’ mark
‘BROWN’ mark
Caution
To prevent electric shock do not remove
the cover
Upon receipt of the amplifier shipment, please
inspect for any damage incurred in transit. If
damage is found, please notify your local representative and the transport company immediately. State date, nature of damage and whether
any damage was noticed on the shipping container prior to unpacking. Please give the waybill
number of the shipping order.
The unit should not be placed in areas;
1. with poor ventilation
2. exposed to direct sunlight
3. with high ambient temperature or adjacent to
heat generating equipment
4. with high humidity or dust levels
5. susceptible to vibration
Unpacking
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Doc No. DCP0000518 JH 12/7/99 rev2
Read this manual throughally before starting installation, the following procedure should
be used.
1. Install the loop (see page 6)
2. Before connecting a loop to the amplifier use a
multimeter to check the loop is not shorted to
ground at any point, (it will almost certainly
damage the amplifier if it is).
3. Connect music or speech input signal to the
amplifier. The peak line level of this signal
should be approximately 1V.
4. Ensure input levels controls and drive control
are fully anti-clockwise. .
5. Increase the input level controls until the ‘limit’
LED is just flashing. This indicates that the
dynamic range processor is receiving a signal
of the correct level. If you are using both inputs
the level controls act as a simple mixer.
6. Adjust the drive control until the required cur-
rent peak is produced. (see page 5). Care
should be taken when doing this to ensure
the current is within the recommended
rating of the cable. The average current
output should be approximately one quarter of the maximum peak.
7. Using an induction loop receiver (eg SigNET
Rxti2), listen to the signal inside the loop. It is
also advisable to check the system with a field
strength meter. Please note that the orientation
of the field strength meter may influence the
reading.
Mains Hum
Background hum can sometimes be heard
when testing an installation especailly when testing with a induction loop reciever. This is not
caused by the loop system and will NOT normally be heard by hearing aid users, due to built
in filtering in most hearing aids.
The source of the hum is most likely to be
mains wiring, particularly in old buildings where
Live and Neutral cables may take different
routes, thus creating an induction loop radiating
at 50Hz.
If the client complains of mains hum simply
disconnect the loop to prove that the source is
unrelated.
Installation Input connections
Two input connectors are standard 3pin
XLR. One input is for line level the other for mic.
level signals. For pin connections use the following chart or see the back of the unit which has
the pin outs marked next to the relavent connector.
LIne Input
Microphone input
Unbalanced Balanced
pin1 ground pin1 ground
pin2 signal pin2 Hot
pin3 link to pin1 pin3 Cold
Unbalanced Balanced
pin1 ground pin1 ground
pin2 signal pin2 Hot
pin3 link to pin1 pin3 Cold
Phantom is supplied on pins 2 and 3,
44V, 5mA maximum per pin.
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