396 AGC Settings

[ems170]

Just have a few technical questions about the AGC settings on the 396.
When you access the hidden menu (power up with the func and hold button held) you are able to fine tune the analog and digital AGC settings. Some people have posetd alternet settings in the past for improved audio performance. My question is what does each of the different settings mean and how do altering the numbers effect the performance? I am looking for definitions of the following.

under Digital settings.

Ref Gain?
Res Time?

Under Analog Settings

GN Range?
Res Time?
Ref Gain?

Also if anyone can refresh my memory about the digital end code and why it should be set to ignore.

Thank you for your help.

 

[ROCKnTIME]

P25 AGC Settings
To access these settings:,
1. Press [HOLD] while turning on the scanner.
2. Turn on the Digital AGC option.
3. Tune to a digital channel.
4. While receiving a P25 signal, hold F then tap the scroll knob. The scanner displays the current P25 RES TIME parameter setting (see below for option details).
5. Rotate the scroll control to change the setting.
6. F+rotate the scroll to select another setting.

Parameters:
P25 RES TIME
Range: -8 to +8
This parameter determines how frequently the AGC factor updates. Decreasing this value makes AGC respond faster, but could result in “pumping.” A higher value decreases the response time.
P25 REF GAIN
Range: -5 to +5
This parameter determines the reference level that AGC attempts to adjust the volume to. If digital/analog volume is not matched, adjust this parameter.


Analog AGC Settings
To access these settings:,
1. Press [HOLD] while turning on the scanner.
2. Turn off the Digital AGC option and turn on the Analog AGC option.
3. Tune to an analog channel.
4. While receiving a signal, hold F then tap the scroll knob. The scanner displays the current ANA RES TIME parameter setting (see below for option details).
5. Rotate the scroll control to change the setting.
6. F+rotate the scroll to select another setting.


Parameters:
ANA RES TIME
Range: -8 to +8
This parameter determines how frequently the AGC factor updates. Decreasing this value makes AGC respond faster, but could result in “pumping.” A higher value decreases the response time.
ANA REF GAIN
Range: -5 to +5
This parameter determines the reference level that AGC attempts to adjust the volume to. If digital/analog volume is not matched, adjust this parameter.
ANA GN RANGE
Range: 0 to 15
This parameter controls the total dynamic range of the AGC adjustments. A larger value allows a wider variation in volume

 

[ems170]

Thank you. That was very useful.

-Matt

 

[Pars65]

another good info for the FAQ wiki.

 

[kikito]

ANA RES TIME
Range: -8 to +8
This parameter determines how frequently the AGC factor updates. Decreasing this value makes AGC respond faster, but could result in “pumping.” A higher value decreases the response time.

The actual values for ANA RES TIME are: -4 to +6

 

[RISC777]

Needs to go into the 996 Yahoo Group database too (if it's not already there...at least a link to pages 4 and 5 of the firmware release notes .pdf file).

 

[ROCKnTIME]

Also if anyone can refresh my memory about the digital end code and why it should be set to ignore.

This setting determines how the scanner handles the
transmission end code sent by most Motorola systems.


Yes - the scanner immediately returns to the control
channel when it detects the end code.

Ignore - the scanner does not return to the control
channel until the carrier drops.