Un-doing the old AGC tweak?

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W2SJW

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Guys,

I noticed that the custom settings used by doing the AGC tweak in the hidden menu have stayed put after the firmware upgrade.

P25 Res Time = -7
P25 Ref Gain = +3

Does anyone remeber what the 396's default settings were? I want to run some tests to see if should be left 'tweaked', or set back to default.

Thanks in advance!
 

UPMan

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The defaults are 0, 0.
Analog defaults are 0,0,+6.

(This is in the release notes.)
 

W2SJW

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Paul,

I'm also assuming that you recommend placing those values back at defaults, right?

Thanks for the fast reply, BTW!
 

UPMan

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Well, we had input from about 40 people in many different locations when determining those initial settings. But, we also knew YMMV, so we made the tweaks available.

Note that, from my observations (not scientific) it seems that 75% of audio imbalance is due to improper conventional channel mode setting (NFM when it should be FM, so the audio is too loud on conventional channels) which is better handled by changing the mode from AUTO to FM for those channels. 20% is a real imbalance by the users on the systems themselves (I've found that firefighters tend to use better radio protocol, speaking directly into the MIC which gives better modulation ... LEO's are more likely to use shoulder mics where they talk "past" the mic and undermodulate). There is only so much that audio AGC can compensate for in a live transmission. I can do great things with recorded transmissions, though. :)
 

GTO_04

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UPMan said:
Well, we had input from about 40 people in many different locations when determining those initial settings. But, we also knew YMMV, so we made the tweaks available.

Note that, from my observations (not scientific) it seems that 75% of audio imbalance is due to improper conventional channel mode setting (NFM when it should be FM, so the audio is too loud on conventional channels) which is better handled by changing the mode from AUTO to FM for those channels. 20% is a real imbalance by the users on the systems themselves (I've found that firefighters tend to use better radio protocol, speaking directly into the MIC which gives better modulation ... LEO's are more likely to use shoulder mics where they talk "past" the mic and undermodulate). There is only so much that audio AGC can compensate for in a live transmission. I can do great things with recorded transmissions, though. :)

How true! My favorite is when they point the shoulder mic right into a 40 MPH wind and try to talk. The dispatchers find it annoying to since they can't hear anything they're saying! Do the radio users ever get any training?

GTO_04
 

Sjinndoawi

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Yes the default is (0,0) and I notice this was not a good thing ..If I am at this setting (0,0) after the update everything was very BAD...clicking, very low audio if any, P25 Link just flashing.. So I started to work from there and found my happy setting is (-4,-2) and WHAT a difference that made.Also did the Digital End Code form "ignore" to "Yes"..Its like night and day ...I have (2) 996t so I could run a control against the other one ..It took me 2 hours of testing at 10:30 last night.............. i.e ( +1,0, no Digital End Code, Turn on Digital ACG, run the same system on the other 996 witout these settings) and vice versa...One marked thing I did notice as running the test..... as I got closer to a optimal setting not only did the audio get clear(less motorboating, less clicking)it start to speed up..I watch the LCD on the scanner and it was getting faster,channels just flipping by so I knew something was up....
 

800crazy1

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UPMAN , i thought everything was going automatic , that the settings were to remain in place for USAD ? so we can still tweak both the anolog and digital settings ?
 

UPMan

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AGC has nothing to do with P25 threshold (or decoding) P25 threshold is now automatic. AGC is as it was before.
 

W2SJW

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OK, I put my 396 back to 0 and 0 on the P25 AGC until someone comes up with a good consensus about weather the old AGC tweak settings are too aggressive to be used with the new decode rates, or that they can stay the same.

I was getting great performance all last night with the -7 and +3 settings, completely forgetting that the tweak was still in there (until another user here on the board brought it up in an unrelated post).
 
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