User's Manual

1892 1344 - SX450G Transceiver Operator Guide v1.2 / Dec 2006 5
PL1-12 PL1-12 CS5 channel select input
(MSB)
PL1-13 - not connected -
PL2-1 PL1-14 RF DET TX RF present flag
output
HIGH (+5V, internal 10K pull-up) = TX RF
present
LOW (0V) = no TX RF
NOTE: only available when high TX RF power is
selected
PL2-2 PL1-15 AF O/P receiver audio output 600mV p.p. nom. into 10K; AC-coupled; Rout =
2K3.
PL2-3 PL1-16 SQO squelch flag output NPN open collector via 470O; ON = no signal,
OFF = signal present.
(NOTE: OFF when transceiver in standby mode)
PL2-4 PL1-17 OOL out-of-lock output NPN open collector via 470O; ON = out of lock
(NOTE: OFF when transceiver in standby mode)
PL2-5 PL1-18 DMOD digital modulation
input **
+3V to +12V square wave, DC-coupled
** DMOD and AMOD may not be used
simultaneously. Leave unused input
unconnected.
PL2-6 PL1-19 AMOD analog modulation
input **
750mV p-p., AC-coupled (pre-settable 200mV to
3V p-p.)
** DMOD and AMOD may not be used
simultaneously. Leave unused input
unconnected.
PL2-7 PL1-20 RSSI 'S' meter output 0V to +3V output, rising with received signal level
(typ. 50dB range)
PL2-8 PL1-21 SQOR squelch override input HIGH (>+2.0V) enables AF O/P regardless of
squelch state (RX only)
LOW (+0.8V or o/c) = normal operation
(internal pull-down, 70K to 0V)