Monitor Polarity- The monitor input is used to override the action of the receiver squelch (mute)
when squelch is active. This function sets the polarity, active low or active high, of this input.
When active, squelch is disabled, even is enable via the Squelch Enable setting above.
PTT/RTS Input Logic Level- Sets the polarity of the PTT/RTS input. Normally set for active low
i.e. transmitter is activated when this input is at the logic low state.
Due to the internal pull-up
resistor, setting this to active high will cause activation of the transmitter when the
PTT/RTS input is left unconnected.
The factory default is active low.
Green LED- Sets the operation of the green LED on the front of the radio. The choices are:
a. Off-The green LED is never on.
b. Power ON-
The green LED is on whenever the radio is powered up.’
c. Carrier Detect-The green LED is on whenever a carrier is detected that is above the
programmed carrier detect on threshold.
d. RX Synthesizer Lock-The green LED is on whenever the frequency synthesizer is
locked while in receive mode. This is the factory default setting.
Red LED- Sets the operation of the red LED on the front of the radio. The choices are:
a. Off-The red LED is never on.
b. RX-The red LED is on whenever the radio is actually transmitting. This is the factory
default setting.
TX Timeout Timer- Allows for limits on the maximum time the transmitter may be continuously
keyed. When set, the maximum limit is set in the box. To prevent overheating and possible
damage to the unit, this is normally set on with a time of 60 seconds of less. See section 5.4 for
limits on maximum key-down times. The factory default is 60 seconds.
6.5.3 ALIGNMENT
The alignment page is used for setting the values of the digital gain settings which are used for
aligning the unit and setting the gains of the audio paths. The unit leaves the factory already
aligned, but the user may wish to change the values of some of the input and output gain
settings. Different systems or modems may require different input and output levels.
Audio Input (TX) Gain- This input allows adjustment of the signal level to be applied to the
modulation limiter and filter circuits from either the AUX IN or MIC IN inputs. At the maximum gain
setting, the AUX IN signal input can achieve 60% rated modulation with about 25 mv rms input
signal while the MIC IN signal can achieve the same modulation with 4 mv rms in the low gain
position and 0.5 mv in the high gain position. The setting can vary from 0 for muted input to 32 for
maximum gain.
Aux Out (RX) Gain- Sets the audio level of the AUX OUT output and
also affects the level of
the AUDIO OUTPUT, even though the AUDIO OUTPUT has its own level control (see Audio
PA Gain below).
Carrier Detect On and Carrier Detect Off- Sets the carrier detect on and off values in dBm. For
proper operation, always set the carrier detect on value to a higher level than the carrier detect off
value. Typical values might be -100 dBm for carrier detect on and -114 dBm for carrier detect off.
The difference between the two values represents the squelch hysteresis and is used to prevent
squelch chatter when the receive signal is near the squelch setting values. Typical hysteresis
would be between 2 and 4 dB.
TX Frequency Trim and RX Frequency Trim- These values allow the transmitter and receiver to
be trimmed on frequency. A typical adjustment range is about +/-2 kHz. This adjustment is set at
the factory and should not be changed except by trained service technicians with the proper
equipment.
