Service manual

Service Manual SD170E Series
Page 22 of 44
Squelch open (un-mute) at -114 to -113dBm (0.45 - 0.5mV of the RX signal strength)
Squelch close (mute) at -117 to -116dBm (0.3 - 0.35mV of the RX signal strength)
Changing the default squelch settings requires use of the programming cable and software.
Those are designed for use not only as part of the programming kit but also as a tool of squelch
level setting.
Still using the same connections for the receiver performance test; run the programmer ACC-
916E on the PC and select calibration mode. Select “Custom Define” menu of Squelch
program menu of ACC-916E.
Adjust the RF signal generator for the desired signal strength to OPEN squelch (e.g. default
setting is approximately –113dBm, equivalent to 0.5mV)
Press “Set OPEN)” button,
Adjust the RF signal generator for the desired signal strength to CLOSE squelch (e.g. default
setting is approximately -116dBm, equivalent to 0.35mV). Press “Set (CLOSE)” button
Press “SAVE” button,
Squelch level is now set. Test for the desired level by increasing or decreasing the RF signal to
levels set for open and close squelch
Brief block signal flow diagrams for each input are the following (See Figure 3.1. ~ 3.3.).
A
A
A
l
l
l
i
i
i
g
g
g
n
n
n
m
m
m
e
e
e
n
n
n
t
t
t
s
s
s