35
Level Setting of System Components
All termination jumpers should be in the high impedance position
except for the last
deskset
at the end of each line. If there is only one deskset, then it
is
the end of the line. Set
this deskset to the low impedance mode (JP1 = Position A for 2-wire, and JP4 = Position
A for 4-wire. For the Model 284, also set jumpers JP3, JP8, and JP9 to Position A for 4-
wire, and set jumpers JP2, JP7, and JP10 to Position A for 2-wire).
Level Setting of System Components
The matter of setting the transmit audio levels out of the remotes in the system will be
discussed from two perspectives; a system with only one remote, and a system with
multiple remotes. In the case of a single remote, methods involving external test
equipment, and a fall-back method if no test equipment is available will both be discussed.
In a system using multiple remotes, you should be able to complete the level checks
without additional test equipment.
After the audio level from the individual remotes has been set, you can then use any of the
remotes as a source of audio for setting the transmit deviation at the base station.
These examples are written for the Model 280 remote and only refer to R3 as the transmit
level control. When working with a Model 284, the procedure is the same except that the
correct line should be selected, and the correct level control for the line selected must be
used. (Line 1 = R3, Line 2 = R14, Line 3 = R100, Line 4 = R99)
Setting TX Audio Level Using External Test Equipment
The first procedure given assumes that the installer has some sort of external test
equipment (multi meter or oscilloscope) available to measure the remote’s transmit level.
Attach the test equipment across the transmit wire pair. This will be the wires attached to
TB1-8 and TB1-9, regardless of whether this is a 2-wire or a 4-wire installation. The
transmit pair must have a 600
load on it for this test to work correctly.
Enter into the front panel Setup mode by pressing the function keys #1 and #8, as shown in
.
Note
The “Transmit Level Set” test used in the following procedures will
not only cause the remote to put audio tones on the transmission
line back to the termination panel, it will also key the transmitter on
whichever channel was selected prior to entering the Setup mode
on the remote. The installer should ensure that transmitting on the
channel selected will not cause any interference with other radio
users before starting the test. If it is necessary to select another
channel, exit the Setup mode and do so before starting the test.