BCD436HP: P25 O F T

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dave3825

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I have a freq programmed in as a p25 one freq trunk. I noticed the signal indicator is showing activity when there is no activity. And there is nothing showing on the bottom of the display where dat, enc etc . I am watching the freq in sdr# and there is no activity.

Anyone else seeing signal activity when there is none? Is this normal?

Thanks
 

jonwienke

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Yes. The system may be broadcasting control channel info, which will show as a transmitted signal, but there will not be voice traffic. Standard P25 systems do the same thing.
 

GTR8000

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Where did he say anything about a trunked system or control channel? He said a P25 frequency, which sounds like conventional P25 to me.

Dave, you need to be clearer about exactly what you're programming so that you'll get an appropriate answer. Assuming, of course, that people actually read your posts before jumping in.
 

dave3825

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Yes. The system may be broadcasting control channel info, which will show as a transmitted signal, but there will not be voice traffic. Standard P25 systems do the same thing.
While the scanner shows strong signal strength on the freq, I see no activity on the freq while watching in sdr# at the same time as the scanner. I am not seeing the data on sdr#, in fact, I don't even see a carrier. There is nothing there. If the system is transmitting system data, that the scanner is receiving it would be seen in Sdr#, and its not.

Dave, you need to be clearer about exactly what you're programming so that you'll get an appropriate answer.
While I wrote "I have a freq programmed in as a p25 one freq trunk" It is actually a conventional P25 freq programmed as (p25 one frequency) to see radio id and talk group info.
 
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jonwienke

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While the scanner shows strong signal strength on the freq, I see no activity on the freq while watching in sdr# at the same time as the scanner. I am not seeing the data on sdr#, in fact, I don't even see a carrier.
That is weird. I don't have an answer for that.

Unless you have multiple system sites programmed, or a site with more than one frequency.
 

GTR8000

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While I wrote "I have a freq programmed in as a p25 one freq trunk" It is actually a conventional P25 freq programmed as (p25 one frequency) to see radio id and talk group info.
Which is what I took it to be, a regular old conventional P25 channel, not part of a trunked system.

That is certainly bizarre that there is no carrier on the frequency, as confirmed with a second receiver, and yet the scanner's RSSI bars are lit up like there is one? What happens when you remove the antenna from the radio, do the RSSI bars disappear?


Unless you have multiple system sites programmed, or a site with more than one frequency.
You're still not bothering to actually read his posts. This has nothing to do with a trunked system or sites. :roll:
 

jonwienke

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You're still not bothering to actually read his posts. This has nothing to do with a trunked system or sites. :roll:
Sentinel requires that all frequencies in DMR and P25 "one frequency" systems be entered in system sites. Sentinel also allows the programming of multiple sites and site frequencies in "one frequency" P25 and DMR systems. So you might wanna dial the snark back just a tad bit.
 

UPMan

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I have a freq programmed in as a p25 one freq trunk. I noticed the signal indicator is showing activity when there is no activity. And there is nothing showing on the bottom of the display where dat, enc etc . I am watching the freq in sdr# and there is no activity.

Anyone else seeing signal activity when there is none? Is this normal?

Thanks
Please provide specific information (frequency/system/link in RRDB).
 

dave3825

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Upon closer inspection, I am seeing it on all the conv freqs programmed in as p25 one freq. Never thought about it before and figured that's how it was supposed be. But if there is no carrier, then there should be no signal strength being shown.

The Vhf freqs are showing 5 bars if signal and the Uhf are showing 1 to none. All are separate systems with one site and one frequency each

Fire Island National Seashore https://www.radioreference.com/apps/db/?aid=9498
Code:
171.62500 4F9 NAC FireIslandNS  Park Operations P25  Federal
Transportation Security Administration https://www.radioreference.com/apps/db/?aid=4910
Code:
172.90000  001 NAC TSA Transportation Security Administration (TSA) P25 Federal
Immigration and Customs Enforcement https://www.radioreference.com/apps/db/?aid=9501
Code:
408.20000 270 NAC FPS Federal Protective Service P25  Federal
Drug Enforcement Administration https://www.radioreference.com/apps/db/?aid=9501
Code:
418.95000  156 NAC DEA Stop 6 Stop 6 P25 Federal
 

UPMan

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Not seeing that when I program the freq. What happens if you take off the antenna?
 

GTR8000

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Have you taken the antenna off like I suggested last night to see if anything changes?

That's the first thing you need to do so you can attempt to figure out what's going on. It could be internally generated noise from the scanner, or a nearby source of interference that the RTL dongle is just not picking up for whatever reason.
 

dave3825

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So with the antenna unplugged, all reception bars are gone. This is with an amp and an antenna for 136-174 mhz. Might be overload due to the amp.

But if I put the radio shack 800mhz antenna on, with out any amp, I get 1 bar of signal strength on the uhf freqs listed above while scanning the p25 one freqs. The p25 one freq systems are both UHF and VHF.

So now, if it is overload, why does it only show signal strength on the p25 one freqs and not any of those freqs in conventional mode?
 
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