Specifications
183
Setting Levels in the Model 620x
• A land line, cell phone, or radio link so instructions can be passed between the
dispatch center equipment room and the station at which the Model 6203 is located
Initial Conditions
• The new Model 6203 or Model 6204 units have been configured and installed at
their permanent fire station locations.
• The Model 26 that controls the system has been programmed as necessary to
account for the new transponder units in the system.
• The necessary personnel are at both the Model 26 and the transponder locations,
there are laptops or PCs connected and ready to enter the serial programming mode
to place the units in FFSK test mode when required
• The system is quiet and expected to remain so for long enough to accomplish the
level setting procedures for the new unit(s).
Setting FFSK Levels in a Radio-based System
♦ Setting the Model 6203 receive level:
1. At the Model 6203 location, connect an oscilloscope to measure the receive audio
signal at TP-1 on the Model 6203 motherboard. The expected signal will be
approximately 1.0 Vp-p (0.35 Vrms).
2. On the Model 6203 motherboard, 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 {7} FFSK Test Menu.
Tip Do not try to set 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.
Tip If there is an external control on the radio transceiver that allows
people to alter the receive audio level going to the Model 6203, this
control must be locked in some way after the adjustments are
made. Changing the level of the receive audio presented to the
Model 6203 can compromise the decoding of FFSK data packets.