Durham Viper reception problem

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BCasto

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Durham City reception problem

Using a BCD996XT receiving Durham City. I live on the Cary Morrisville boarder near Chapel Hill Road and Weston Parkway.

Even when I have 4 to 5 bars of signal strength, voice traffic comes and goes and the scanner doesn't stay fixed on the control channel. There are indications a TG is active but there is no voice. P25 error rates are pretty variable and can get very large and the threshold setting fluctuates wildly. When off the CC it displays NFM. It is set up as P25 Standard Trunk. Control Channels are the only frequencies.

Supposedly the scanner "learns" and over time should find the best threshold level, but that doesn't seem to be happening.

Would love some ideas from the bright people here. Thanks a bunch.
 
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BCasto

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Update

Out of desperation I attached 2 telescoping antenna to a t-splitter to the scanner. It seems to vastly improve the reception, digital decoding, etc. The 2 antennas are just about 3 inches apart, which is almost a quarter wave. Thoughts?
 

drayd48

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I would almost say it would be in your antennas. The CC on my scanner comes in as an FM signal which is easier for the scanner to receive. That is why the bars are higher. When a digital talkgroup becomes active, the CC assigns the scanner to go to a certain frequency to listen on. That frequency is using digital which does not travel as far as FM signals
 

trumpetman

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I would almost say it would be in your antennas. The CC on my scanner comes in as an FM signal which is easier for the scanner to receive. That is why the bars are higher. When a digital talkgroup becomes active, the CC assigns the scanner to go to a certain frequency to listen on. That frequency is using digital which does not travel as far as FM signals

I'm not sure I follow? It's all digital, it's all the same type of signal, it all travels the same distance. It may very well be the antenna causing the issue, but not based on your science.

First things first, is the OP listening to the Durham 5C9 simulcast system that carries all the local public safety talkgroups, or are you listening to the VIPER 1FC system which carries NCSHP, Duke University, & other state agencies?
 

BCasto

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More information

I am trying to listen to the City of Durham listed as Durham Prime Site (05C9h-0102 when the site is on hold). The CC is 857.6875Mhz. What is so strange is the way the signal comes and goes. In one minute it is 5 bars and the next 0 bars. And when there is reception the signal strength fluctuates a lot. That means the scanner doesn't hold on the CC and I miss a lot of traffic. There are times though that it comes in booming, like right now at 1:53pm.

According to lat long math my house is 16.8 Miles from the antenna site. RR.com says the antenna coverage is 15 miles.
 
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