ZETRON 025-9581M, Installation And Maintenance Manual

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Model 26 Backup in a VoIP System
Model 26 FFSK Transmit Level
This procedure will require personnel at both the Model 26 location and at one of the
Model 6203 station locations.
♦
Setting the Model 26 FFSK transmit level:
1. At the Model 26, connect the laptop (or PC) to the serial programming port of the
Model 26. Set Switch 7 on the rear of the Model 26 to the ON position (places the
unit in the programming mode). Hit the SPACE bar three times to open the Model
26 Main menu.
2. Enter a “ 7 ” to open the {7} FFSK Test Menu.
3. Enter a “ 1 ” to initiate the FFSK test mode. The Model 26 should key its radio and
transmit for 30 seconds and then unkey. If you finish making adjustments before
30 seconds is up, you can cancel the test by hitting any character key on the
computer keyboard. If you require more time to make the adjustments, enter the
“
1 ” again to repeat the test tone.
4. While the FFSK test tone is being transmitted by the Model 26, use the service
monitor to measure the deviation of its radio transmitter. Adjust the FSK XMIT
pot (R79) on the back of the Model 26 for a deviation of 2.5 kHz (assuming wide
band operation and a full channel deviation of 5 kHz). If the signal cannot be set
low enough, move
JP10 in the Model 26 from position B to C . If the signal cannot
be set high enough, move JP10 from position B to A .
5. When finished making adjustments, let the test signal time-out or stop the test.
6. Leave the laptop attached to the Model 26 and leave it in the FFSK Test menu for
now.
Tip Do not try to set Model 26 or Model 6203 transmit or receive levels
based on FFSK packets exchanged in normal polling. To do so can
lead to erroneous level settings. Only set levels while using the test
tones generated by both units.
Caution! Some radios exhibit a roll-off of the audio at higher
frequencies. If this roll-off is severe enough, it can compromise
the data integrity of the FFSK packets. The radios used and the
interface to them should be configured to provide a flat
frequency response (as much as possible).
!