User's Manual

MM102558V1 R1A
5.6.6 Squelch Tail Elimination
Squelch Tail Elimination (STE) eliminates the burst of squelch noise heard when the received carrier
drops immediately and the CG circuit is still un-muted. When using STE, the transmitter remains keyed
for a short duration when the PTT is released.
When STE is enabled during CG tone signaling, STE directs the CG tone to be phase shifted by 135-
degrees. If the CG detector in the receiving station is equipped with STE, the detected phase shifted CG
signal will cause the receiver to mute the audio path before the carrier ends.
When STE is enabled during DCG signaling, STE directs the DCG tone circuit to encode a square wave
when the PTT is un-keyed, which continues until the end of the carrier transmission. When detected by
the receiving station, the square wave interrupts the DCG signal pattern and mutes the receive audio
before the received carrier ends thus eliminating any burst of squelch noise.
5.6.7 Drop Out Delay Timer
The Drop Out Delay Timer (DODT) clocks the time after a PTT un-keys till the carrier ends. When set,
the transmitter remains keyed after all PTT signals are finished for the specified time duration. This timer
may be set from 0 to 10 seconds, in 10 millisecond increments.
5.6.8 Control Shelf Options
The System Module also provides programming for certain Control Shelf options. These options include
Morse Code ID, Voting, Battery Alarm, Aux RX, Logic Standby, Intercom, RX IF Bandwidth and
receiver channel scan.
5.6.8.1 Morse Code ID
A Morse Code ID may be programmed into each channel defined in the personality. This feature may
also be enabled or disabled on a per-channel basis. Up to twelve (12) consecutive characters from any of
the standard 26 letters of the English alphabet, numbers 0 through 9 and the “ / ” forward slash bar may be
entered as a part of a CW ID. No spaces may be programmed within the twelve consecutive characters.
The Morse Code ID is sent at a rate of 20 words-per-minute and may be programmed for intervals of 5 to
30 minutes, defaulted to thirty minutes, with a wait time interval (pause time after CAS or line signal
ends) of 0 to 10 seconds in 100 millisecond steps. The ID may be programmed to send either with or
without Channel Guard encoding.
5.6.8.2 Battery Alarm
During battery stand-by power conditions, the station power supply applies a battery standby signal to the
T/R shelf backplane. The signal is passed to the System Module which generates a default 1200 Hz alert
tone and adds it to the transmit audio. The 1200 Hz tone may also be sent down the wire line to any
remote control unit in the system (see note).
A battery stand-by condition will not force the station to key or send a PTT. Rather, over-the-air
transmission of the alert tone occurs only when the station is keyed by normal operations. This prevents
unnecessary battery drain caused by the high current requirement of the station during transmit.
The repetition rate and on-time rate are programmable. The repetition rate sets the time from the
beginning of a tone to the beginning of the next tone, and is programmable from 0 to 25 seconds in
increments of 1 second. The on-time rate sets the duration of the tone burst, and is programmable from
zero 0 to 1 second, in increments of 100 milliseconds.
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