Spectrum DSP M2 - ALC for Transmit Power and Speech Processing; Numerical CMP Settings; Manual CMP;SV Adjustments

Spectrum DSP M2 User Manual V1.1
• Speak normally if using the Microphone input, or set the nominal input level if you are
using the LINE Input mode.
• Use button F2 to select the AUDio meter.
• Use button M1 (below ENC1, the left-hand encoder) to select the on screen CMP
setting and use that encoder to adjust it to a setting of 1.
• Use button M3 (below ENC3, the right-hand encoder) to select the on-screen MIC (or
LIN) setting and use that encoder to adjust it, or you may go into the Menu mode and
adjust the “Mic Input Gain” (or “Line Input Gain” as appropriate).
• While speaking normally, adjust the gain so that the audio meter peaks up to “0” (zero)
to +6 on the audio meter. It is fine for it to occasionally peak higher than this.
• Now use button F2 to select the ALC meter.
• Use button M1 (below ENC1, the left-hand encoder) to select the on screen CMP
setting and use that encoder to adjust it, or you may go into the Menu mode and adjust
the “TX Compress Level”.
• Adjust this setting for an upwards indication of the ALC indicator. See below for a
discussion of this setting.
Using the ALC to control transmit power, or as a speech processor:
There are two ways to adjust the speech processor/compressor settings:
• Using the “CMP” numerical settings (which is the same as the “TX Audio Compress”
menu parameter)
• Setting the “CMP” (or the “TX Audio Compress”) setting to “SV” and independently
adjusting the “ALC Release Time” and “TX PRE ALC Gain” settings.
Using numerical settings for CMP:
When using the numerical settings for the CMP setting (also the “TX Audio Compress”
parameter) the “ALC Release Time” and “TX PRE ALC Gain” settings are automatically
adjusted to provide “compression” settings that become “stronger” with an increasing number.
“Manually” adjusting parameters when “CMP” is set to “SV”:
When the “CMP” (or the “TX Audio Compress” parameter) are set to “SV” the parameters
“ALC Release Time” and “TX PRE ALC Gain” may be manually adjusted as desired to
provide a custom compressor setting.
This ALC system has been designed to be flexible and be usable both as a “standard” ALC
used to set the SSB transmit power and as a highly-effective compressor-type speech
processor. To operate the the ALC in this way requires attention to two separate parameters
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