USING THE LoopHEAR
5. The LH102 is already factory set to
get optimal performances in magnetic
field transmission but, depending
upon your specific requirements, you
can change the magnetic field level
or its frequency response. Use a
small flat blade screwdriver to adjust
the controls for the Loop Current and
Tone Adjustment.
6. Test the performance of the system
using a loop receiver or field strength
meter. Adjust the Tone and Loop
Current controls to achieve the desired performance.
The Tone adjustment enables compensation for loss of higher
frequency signal during transmission.
Turn the Loop Current control clockwise to get the desired
magnetic field level (The Loop Current Indication LED will
become brighter as the Loop current is increased).
7. Loop Antenna & Performance
The unit has a built in loop antenna which is normally sufficient
for most applications.
However to increase the coverage area, one can use an
external perimeter loop with the following characteristics:
Loop resistance 0.3 to 1 ohm
Loop Impedance 1.3 ohm at 1.6 KHz
For local area loops, use wire 0.5 to 1.5 mm2 or 22 to 16 AWG
The external loop can be connected to the unit at the connector
at the back. Just press the latches of the spring clamps and
insert the terminating wires of the external loop. If using the
external loop, slide the selector switch next to the connector to
the External loop position.
12
TM