Vega DSP-223, Technical Manual

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Tone Remote 15
4.2.2.14 Radio TX Audio Filters
The TX Filters button sets the options for controlling the
radio TX audio.
4.2.2.14.1 AGC
The AGC checkbox adds an Automatic Gain Control or
audio compression to the radio TX audio. AGC will help
to increase the level of low audio, and decrease the
level of loud audio, resulting in a more consistent level
being transmitted.
4.2.2.14.2 Add CTCSS to TX
When checked, Add CTCSS to TX will add the selected
CTCSS tone to the TX audio stream. The CTCSS output (pin 11 of the DB25 connector) continues to be
active. This allows CTCSS to be sent on radios that don’t have separate input pin for its injection into the
audio stream. The user will need to make certain that no high pass filter is in place in the radio to cut off
the CTCSS audio.
4.2.2.14.3 Pre-Emphasize Audio
The Pre-Emphasis Audio option will add a pre-emphasis zero and pole into the radio TX audio stream.
The frequency response can be seen in Figure 16
4.2.2.14.4 3.5kHz Low Pass Filter
The 3.5kHz Low Pass Filter attenuates frequencies above the cutoff frequency in the transmit audio
stream. The frequency response can be seen in Figure 15
Figure 12 TX Audio Parameters Screen