Product manual

Setting FFSK Levels in a Wire Line-based System
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the computer keyboard. If you require more time to make the adjustments, enter
the “1” again to repeat the test tone.
5. While the FFSK test tone is being transmitted by the Model 26, use the
oscilloscope or voltmeter connected to the Model 26 to measure the test signal.
Adjust the FSK XMIT pot (R79) on the back of the Model 26 for a level of 1
Vp-p (0.35 Vrms). 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.
6. When finished making adjustments, let the test signal time-out or stop the test.
The final position of JP-10 and the approximate position (for example, 10:00
o’clock) of R79 should be recorded in Appendix A of the Model 26 Fire Station
Dispatcher Product Manual for future reference.
7. Leave the computer attached to the Model 26 and leave it in the FFSK Test menu
for now.
Model 6 Receive Sensitivity
Set the Model 6 FFSK receive sensitivity by performing the following steps See Table 8
for initial jumper settings. See
Table 9 for potentiometer information. See Figure 29 for
locations.
♦
Setting the Model 6 FFSK receive level:
1. At the Model 6 location, connect an oscilloscope to measure the receive audio
signal at TP-1 on the Model 6 motherboard. The expected signal will be
approximately 1.0 Vp-p (0.35 Vrms).
2. On the Model 6 motherboard, set controls R107 and R135 according to whether
this is a 2-wire or 4-wire system.
• 2-wire = turn R107 fully counterclockwise and R135 fully clockwise
• 4-wire = turn R107 fully clockwise and R135 fully counterclockwise
3. Turn R62 (FFSK IN) fully counterclockwise. Set R86 (VOX threshold) to the
middle of its range.
4. Call the Model 26 site and have the operator there initiate the FFSK Test signal
from the Model 26.
a. At the Model 26, connect the laptop (or PC) to the serial programming port
of the Model 26. Hit the SPACE bar three times to open the Model 26 Main
menu.
b. Enter a “7” to open the FFSK Test Menu.
c. 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.