S E T U P F O R M
C H A P T E R 4
Attack (ms):
This sets the time constant for the attack for the AGC, When a signal gets
stronger, this determines how quickly the AGC will respond to the need for decreased gain.
Note that in order for this and the two controls below it to be enabled, the AGC control on the
front panel must be set to Custom.
Decay (ms):
This sets the time constant for the decay for the AGC. When a signal gets
weaker, this determines how quickly the AGC will respond to the need for increased gain.
Hang (ms):
To keep the AGC system from adjusting too much, an adjustable hang time is
provided. This Hang time will only be applied if the signal level is above the Hang Threshold
(see below), otherwise a fixed “Fast Hang” time of 100ms is applied. After this time has
expired, the Decay will then determine how quickly the AGC gain recovers.
Hang Threshold:
The Hang will NOT
occur if the signal is weaker than this threshold. Instead
the “Fast Hang” will be applied.
Fixed Gain
: When you choose Fixed AGC on the front panel, this control is used to amplify the
signal.
Table 9 details the AGC parameters used in the various settings.
Table 9: AGC Setting Details
Setting
Attack
Decay
Hang
Fast Hang
Fast
2ms
100ms
100ms
100ms
Med
2ms
250ms
250ms
100ms
Slow
2ms
500ms
500ms
100ms
Long
2ms
2000ms
750ms
100ms
Leveler
The Leveler is intended to even out the variations in input to your microphone caused by varying
distance from or angle presented to it. It is an attempt to “level” the amplitude presented to the rest of
the DSP audio processing. The leveler is
disabled
in DIGU and DIGL modes.
ALC
The ALC is what you would typically consider ALC to be in a transmitter. It is an attempt to prevent
overdrive of the amplifier and the distortion that would accompany that. Because of the dual track AGC
algorithm we use, this ALC will allow very high average power while maintaining peaks at a controlled
level. The Compander (
DX
and
CPDR
on the Front Console (see Mode Specific Controls – Phone on
page 59) work very well with the ALC to increase average power without overdrive.
[The rest of this page has been left blank intentionally]
110
2003-2008 FlexRadio Systems