Please explain 396 "tweak"

Status
Not open for further replies.

ButchGone

Member
Joined
Jan 9, 2004
Messages
834
Location
Ringgold, Georgia
OK, I see the 396 digital AGC tweak page on the WIKI and understand what the instructions say to do. But to help me understand what these settings mean and to better tweak to my systems, please explain what the "P25 RES Time" and P25 REF gain" values mean. What does a minus value mean in terms of reception versus a positve value? Understanding what the values mean may help me and others trying to tweak 396's.
Thank you in advance!
BG..
 

John_M

Member
Joined
Mar 8, 2005
Messages
1,486
Location
Rochester, N.Y.
The basic instructions for the AGC can be downloaded from Uniden. The only people who could specifically tell you what "P25 RES Time" and P25 REF gain" mean would be somebody from Uniden. It is a control system just like the thermostat in your home. In / Out with feedback. Paul should be able to shed some light on the subject. The Digital AGC tweak is listed as being Unofficial and not supported by Uniden (yet). They may change things
in a firmware update.
 
Last edited:

slicerwizard

Member
Joined
Sep 19, 2002
Messages
7,172
Location
Toronto, Ontario
ButchGone said:
please explain what the "P25 RES Time" and P25 REF gain" values mean.
RES Time (P25 or ANA) controls how frequently the scanner will adjust the volume, hence how quickly it will respond. Lower values = faster response (e.g. less time delay between adjustments). Very low values can trigger "pumping", where the volume jumps up and down.

REF Gain (P25 or ANA) sets the target volume level. They can be used to match analog and digital volume levels.

Negative values just represent the lower end of the adjustment ranges. Typically, zero represents a "normal" or default setting, while negative values represent below normal settings.
 

wjf

Member
Joined
Jan 15, 2006
Messages
484
Location
Witness Protection Program
[
slicerwizard said:
RES Time (P25 or ANA) controls how frequently the scanner will adjust the volume, hence how quickly it will respond. Lower values = faster response (e.g. less time delay between adjustments). Very low values can trigger "pumping", where the volume jumps up and down.

REF Gain (P25 or ANA) sets the target volume level. They can be used to match analog and digital volume levels.

Negative values just represent the lower end of the adjustment ranges. Typically, zero represents a "normal" or default setting, while negative values represent below normal settings.
"John_M:
(parameters)
Out

(feedback with/without parameters) Out
In

At least this is how I believe it works."



Thanks. I'm still dizzy about the craziness John_M posted!
 
Last edited:

John_M

Member
Joined
Mar 8, 2005
Messages
1,486
Location
Rochester, N.Y.
wjf Wrote:


"John_M:
(parameters)
Out


(feedback with/without parameters) Out
In


At least this is how I believe it works."


Thanks. I'm still dizzy about the craziness John_M posted!
This is what I was trying to draw with the arrows.

Block diagram of control system:

http://www.tpub.com/content/doe/h1013v2/css/h1013v2_117.htm
Ideally you want it to act as fast as possible to give you the desired output level
(Volume).
 

UPMan

In Memoriam
Uniden Representative
Joined
Apr 19, 2004
Messages
13,296
Location
Arlington, TX
Except that if you have it acting too fast, the AGC will "pump" which would give everyone a nice vibratto (and drive you nuts after a while).
 

ButchGone

Member
Joined
Jan 9, 2004
Messages
834
Location
Ringgold, Georgia
Well now I've tried the digital tweak with no avail. The instructions in WIKI say power up the 396 while pressing the Hold button. I've done this many times and no tweak menu appears. It only goes into normal scan mode. Any suggestions? The firmware version is 1.11.04. Thanks.
BG..
 

rvawatch

Member
Joined
Jun 3, 2007
Messages
274
turn on one of the agc modes through the settings menu, turn off the scanner, press "hold" and "power" to turn the scanner back on, hold "func" and press the knob twice (like how you get to the decode rate), you are now at the agc menu. Hold "func" and scroll with the knob to choose the different selections.
 

Bote

Member
Feed Provider
Joined
Dec 19, 2002
Messages
902
Location
Ft. Lauderdale, FL, U.S.A.
Press Scroll knob twice

The tweak instructions are not clear.

It says to press and hold Function while tapping the Scroll knob once, but then you must wait 10 seconds for the squelch setting to disappear to reveal the AGC tweak setting.

Pressing Scroll a second time clears the squelch adjustment thermometer so that you can see the AGC setting on the bottom line. Alternate AGC settings by holding F and scrolling between them. Let go of F to change the actual numerical setting (tweak it).

I just changed mine, but I actually like the AGC off on the Boca Raton digital trunked system. The AGC just cuts back way too wildly at the start of transmissions for my tastes.
 

ButchGone

Member
Joined
Jan 9, 2004
Messages
834
Location
Ringgold, Georgia
I agree, I like the sound of the 396 withouth the AGC on. The same was true when I briefly had the Pro 2096, which on that model made the digital audio sound more watery. Mileage varies, I guess, since some Moto systems just sound better than others.
BG..
 
Status
Not open for further replies.
Top