Section 5. Installation
5-3
7. COR Input
:
Connect J1/pin-9 (
COR
) to a carrier indication point in the receiver. The
signal available at this point must be between 0 and 11.5 volts DC, and it must change
value by at least one volt between the carrier and no-carrier conditions.
TESTS AND ADJUSTMENTS
These tests and adjustments will need to be done after the Model 37-MAX has been installed
on the repeater and prior to programming the system and placing it in service. The tests need
to be done in order to ensure reliable operation and optimum audio quality on the system. If
this is the first time this test has ever been run on this system, remove the top cover of the
unit before starting, to provide access to the jumpers inside.
1. Carrier Detect
:
After completing the connection of the Model 37-MAX to the repeater,
apply power to both units. Supply and then remove a 6 dB SINAD quieting signal to the
receiver and adjust the potentiometer R35 (
EXT COR
) until the Carrier LED tracks the
presence of carrier and goes off when the signal is removed. If the Carrier LED operates
'backwards', then locate the jumper JP5 (
COR POLL
) and rotate its jumpers a quarter turn.
Readjust R35 as necessary. If necessary, adjust the squelch control on the receiver to
cause the receiver to unsquelch reliably for the test signal. When this step is completed,
the receiver's squelch control will set the threshold for both the receiver and the Model
37-MAX.
2. Initial Receiver Audio Level
:
Using a DTMF equipped mobile radio or portable set to the
repeater's receive frequency, transmit all of the DTMF tones. Adjust the potentiometer R2
(
RX LVL
) so that the Status LED blinks after each digit. If necessary, change the position
of JP3(
RX
).
3. Access Program Mode
:
Set the service monitor to receive on the repeater's transmit
frequency and connect it either to the transmitter output or a suitable antenna. Using the
DTMF equipped radio from step one, enter the program mode access code. It is initially
set to "12037". Once the program mode has been accessed, the 37-MAX will key the
transmitter and send a five-beep "go-ahead" prompt.
4. Transmit Audio Level
:
Enter the DTMF command "392#". The panel will respond by
keying the transmitter and sending a 1 kHz test tone. Adjust the potentiometer R3 (
TX
LVL
) for 60% of full channel deviation (example:
±
3 kHz deviation on a channel licensed
for 5 kHz). If it is difficult or impossible to reach this level, try moving jumper JP4 (
TX
)
to the other position and try again. When finished adjusting the transmit level, enter a
DTMF "#" to exit the transmit audio test.
5. Repeat Audio Level
:
Move the jumper JP3 (
RX
) to position 'A'. Supply a full quieting
signal with a test tone of known deviation on the receiver's frequency. Enter "394#" to
start the repeat audio test, the 37-MAX will key the transmitter and open its repeat audio
path. Adjust the potentiometer R2 (
RX LVL
,
not
R3 -
TX LVL
) for unity gain through the
repeater, that is, the transmitter deviation equals the known deviation of the signal being
supplied to the receiver. If unity gain can not be achieved with JP3 (
RX
) in the 'A'
Summary of Contents for 37-MAX
Page 72: ...Section 6 Repair 6 6 MODEL 37 MAX REPEATER PAL 702 9808A Schematic 1 3...
Page 73: ...Section 6 Repair 6 7 2 3...
Page 74: ...Section 6 Repair 6 8 3 3...
Page 75: ...Section 6 Repair 6 9 MODEL 37 MAX REPEATER PAL 702 9808A Silkscreen...
Page 76: ...APPENDIX A PROGRAMMING LOG A 1 OVERVIEW A 1 SYSTEM PROGRAMMING A 2 USER PROGRAMMING A 3...
