APCO P25 BCD396XT program problems

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Fitzgy1

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I downloaded my local Police Fire & Ems to my new handheld using freescan directly drawn from Radio Reference csv file. I am a police officer and have a radio that I am able to use to test to see if its all up and working. Sometimes it seemed to work fine, and other times it doesn't pick up anything. My display shows "NFM" usually when its not working. I cant figure out what this is. I am setting this scanner up for a friend who wants to listen as our county recently switched to this digital system. I cant figure out why this doesn't always pick up the system. I think I am doing something wrong. Just don't know where to start to trouble shoot. My departments portable radio has full signal. Sometimes, when I transmit on a talkgroup to see if the scanner picks it up, I see the alpha tag que up for a nano second in the display of the scanner but it doesn't hold...even though I am pushing the tx button for an extended time. Any help would be appreciated. If it helps, I am downloading New York State, Ontario county, p25 system police fire and ems for Ontario North and South.
 

Fitzgy1

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Ok, the system seems to be split into north and south, and I dont seems to get any signal with the south so I took that out. I seem to be getting all the mobile communication but not the dispatch side of it. What settings are usually attributed to only hearing one side of the conversation?
 

wtp

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on a 396xt

if you see nfm it means the radio is not receiving the control channel.
the control channel should be there when not receiving any audio and switch to the frequency when it is.
 
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Fitzgy1

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if you see nfm it means the radio is not receiving the control channel.
the control channel should be there when not receiving any audio and switch to the frequency when it is.

OK.. That makes sense. I deleted the simulcast side of the system I wasn't getting signal strength on and that has disappeared. Any idea on setting I should adjust for p25 that would cause me only to hear one side of the conversation?
 

N8IAA

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You are experiencing the 'Simulcast blues' on the 396XT. Sometimes it hears, sometimes it doesn't. Pick the tower that your friend lives closest to, and program just those control channel frequencies. It may work better. Another thing, using the antenna that came with the radio won't work well. Go to the Shack and get the 800MHz antenna for the scanner. It will make a difference.
HTH,
Larry
 

Fitzgy1

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So I am messing with the p25 wait time and hold time for trunking site in free scan software..seem to be getting more and more audio. Just not sure whats best. theres also the apco stuff.
 

ofd8001

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Any chance you could be keying up your radio to see if you get a "hit" on the scanner? What might be happening is that your radio is "de-sensing" your scanner such that it doesn't receive the system.

I had a similar thing happen to my with my fire department radio and it took a little while for me to figure out what was happening.

A couple of other things to try to improve what appears to be challegnes with receiving/decoding P25 simulcast systems :

1. Setting the site attenuator on.
2. Try various P25 Adjust Mode and P25 Adjust Level settings (these are trial and error to see which works best).
 

zilogky

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Radio Dropouts

So I am messing with the p25 wait time and hold time for trunking site in free scan software..seem to be getting more and more audio. Just not sure whats best. theres also the apco stuff.

Google P25 Uniden BCD396XT Dropouts

What is happening is with a simulcast system the same signal is bounced off of multiple towers. If 2 of those signals arrive at your scanner at almost the same time it will cause the scanner to have audio dropouts.

You need to tweak the P25 settings until your audio is decent. The bad part is you can have your scanner setup OK at home, but if you go across town it might get Audio Dropouts.

Remember to save your settings on your computer.

Ed

odieky@gmail.com
 
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