Robotron Pty Ltd G5E 用户手册
WiNRADiO G3XX User’s Manual
Software AGC
In addition to the usual hardware AGC (Automatic Gain Control), the G3XX
receiver also has Software AGC.
receiver also has Software AGC.
This facility is used to compensate for audio volume changes when the
antenna signals are so weak that the hardware AGC is not yet activated, or
when the hardware AGC is disabled and manual IF gain setting is used
instead.
antenna signals are so weak that the hardware AGC is not yet activated, or
when the hardware AGC is disabled and manual IF gain setting is used
instead.
Think of the Software AGC as an “Automatic Volume Control”, which acts on
the demodulated audio signal, while the hardware AGC acts on the
undemodulated intermediate frequency signal.
the demodulated audio signal, while the hardware AGC acts on the
undemodulated intermediate frequency signal.
The software AGC has four settings: Off, Slow, Medium
and Fast. These make it possible to disable the AGC, or
to select the speed with which the AGC reacts. Typically,
the AGC would be in the Medium position.
and Fast. These make it possible to disable the AGC, or
to select the speed with which the AGC reacts. Typically,
the AGC would be in the Medium position.
The timing of slow, medium or fast
speed settings is user-definable
under the Setup button:
speed settings is user-definable
under the Setup button:
The attack time (the speed with which the SAGC reacts to a rising signal level)
as well as the decay time (the speed with which the SAGC reacts to a lowering
signal level) can be adjusted separately.
as well as the decay time (the speed with which the SAGC reacts to a lowering
signal level) can be adjusted separately.
For most practical applications, the medium setting with its default speed
settings is recommended. Slow setting would be used especially with Morse
code (CW mode), while fast setting might be appropriate for very noisy signals
(where noise bursts might temporarily desensitize the receiver if slow decaying
SAGC was employed).
settings is recommended. Slow setting would be used especially with Morse
code (CW mode), while fast setting might be appropriate for very noisy signals
(where noise bursts might temporarily desensitize the receiver if slow decaying
SAGC was employed).
When enabled, SAGC tries to maintain
the audio output at a constant level, the
AGC reference level. This level is user
adjustable under the Setup button,
separately for each demodulation mode:
the audio output at a constant level, the
AGC reference level. This level is user
adjustable under the Setup button,
separately for each demodulation mode:
29