Tait TB8100, Service Manual

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TB8100 Service Manual Glossary 299
© Tait Electronics Limited September 2006
hysteresis
Hysteresis is the difference between the upper and lower trigger points. For
example, the receiver gate opens when the upper trigger point is reached,
but will not close until the level falls to the lower trigger point. An adequate
hysteresis prevents the receiver gate from repeatedly opening and closing
when the level is about that of the trigger point.
Hysteresis mode A mode of PMU operation designed to save power. The PMU is mainly
turned off, but switches back on intermittently to maintain output voltage
when the output current is low.
I
inactive
Digital outputs are inactive if the base station is doing nothing to them.
They are floating, open collector outputs. Digital inputs are inactive when
they are open circuit.
Intercom mode
Intercom mode makes it possible for the operator at the dispatch centre and
the servicing technician at the base station to communicate with each other
over the line. It connects the base station microphone to line out.
isolator
An isolator is a passive two-port device which transmits power in one
direction, and absorbs power in the other direction. It is used in a PA to
prevent damage to the RF circuitry from high reverse power.
K
kerchunking
Kerchunking is transmitting for a second or less without saying anything in
order to test the base station. This results in a ‘kerchunk’ sound.
L
line-controlled base
station
A TB8100 is a line-controlled base station when it receives audio (sending
it out via its system interface), transmits audio received over its system
interface, and its transmitter is keyed via the Tx Key line.
logging on
Once you have connected to a base station, you can log on. This establishes
communications between the Service Kit and the base station.
N
navigation pane
The navigation pane is the left-hand pane of the Service Kit application
window. It displays a hierarchical list of items. When you click an item, the
main pane displays the corresponding form.