Community Repeater Modulation - Motorola R-2001D Operator's Manual

COMMUNITY REPEATER MODULATION
1. Connect the Analyzer to the repeater under test as shown in figure 4-15. The diagram illustrates a MICOR Commu-
nity Repeater. Disable the receiver PL and set the squelch to threshold.
2. Set DISPLAY to DVM, FUNCTION switch to Monitor FM, and MODULATION switch in off position. Set
~
MONITOR BW switch to narrow, Squelch control to threshold, and Duplex Gen switch to off.
3. Set the attenuator to -30 dB. For low-power transmitters, it may be necessary to reduce the attenuator setting to un-
squelch the monitor. Too high an attenuator setting or too tight a squelch setting inhibits the modulation deviation
display.
4. Enter the proper transmitter frequency.
5. Move the display cursor down to DVM and enter 1 for AC mode. Adjust the 1 KHz Level control for 1 VAC, in-
dicated on the display, to put 1 volt of 1 KHz test tone into the transmitter modulation limiter.
6. Set DISPLAY to Oen/Mon Mtr. Key the transmitter. Adjust the transmitter IDC control for 4 KHz DEV indicated
on the display. Un-key the transmitter.
7. Disconnect the cable from the Duplex Gen output to the receiver antenna to prevent the transmitter from keying up
on repeat.
8. Disconnect the cable from the Mod Out connector, leaving SINAD IN connected to test point at the repeater level.
9. Set DISPLAY to Duplex Gen, FUNCTION switch to Generate FM, and Duplex Gen switch to On. Set the MONI-
TOR Image/Duplex switch to High or Low as required. Enter the proper offset frequency.
10. Move the display cursor down to PL or DPL and enter a PL/DPL code used in the repeater.
11. Turn off the 1 KHz Level control. Set MODULATION switch in the Cont position and adjust Code Synth Level
control for 0.75 KHz DEV indicated on the display.
12. Set FUNCTION switch to Monitor. Reconnect the cable from the Duplex Gen Output to the receiver antenna con-
nector. The transmitter should now key-up.
13. Adjust the PL deviation control in the repeater controller for 0.75 KHz repeated PL/DPL code indicated on the
display.
14. Set FUNCTION switch to Generate and adjust the 1 KHz Level control for 4.75 KHz DEV indicated on the display
(0.75 KHz PLlDPL
+
4 KHz test tone
=
4.75 KHz).
15. Set DISPLAY to DVM, FUNCTION switch to monitor, and turn the repeat level to minimum. Slowly increase the
repeat level control until the proper voltage is indicated on the display.
16. Change DISPLAY to Gen/Mon Mtr. Confirm that the repeated modulation is 4.75 KHz.
17. Disconnect the cable from the Duplex Gen Output to the receiver antenna. The repeater should un-key.
18. Radiate a weak signal from the Duplex Gen Output to simulate the weakest signal that will be repeated. Adjust
squelch key control on the squelch gate module to the point that the transmitter just keys-up.
4-26
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