NXDN Repeater output Vs. NXDN Repeater Input

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milo361

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Vernon/ Barton County MIssouri
Hello,

I am attempting to get assistance monitoring one of our local Dispatch and Communications channels that is NXDN 9600 I can decode all but the Dispatch Center when listening to the Repeater Input Frequency, However, when I attempt to monitor the Repeater Out Frequency I get no audio. The waterfall on HDSDR appears to be scattered more than a Solid mass to focus on. I have verified the frequency several times. Pulled straight from the RX on a portable radio that monitors the same frequency.

This is a non-trunked system.
Frequency PPM adjusted for RTL-USB receiver
HDSDR V.2.70
DSD+ V. 1.101pt

Any Ideas.

Thanks for the help.
 

M105

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Sep 13, 2005
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Is it possible that you are not getting a good RF signal from the repeater? The input signals you hear are coming from the mobile units but the fact that you are not hearing dispatch on the input coupled with the possibility that the repeater is also located near the dispatch office, makes me wonder if your signal is being blocked from that direction. Maybe try another antenna or antenna location...
 

milo361

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Jul 12, 2007
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Location
Vernon/ Barton County MIssouri
Is it possible that you are not getting a good RF signal from the repeater? The input signals you hear are coming from the mobile units but the fact that you are not hearing dispatch on the input coupled with the possibility that the repeater is also located near the dispatch office, makes me wonder if your signal is being blocked from that direction. Maybe try another antenna or antenna location...

I believe that the Dispatcher talks out on the RX frequency {repeater out} due to the Dispatch centers tower location. With the portable radio in the same location, I hear nothing on the repeater side when listening to it on HDSDR. The waterfall looks like a displaced wave form with no real focus. I have changed locations on these antennas. I am confused as to why I wouldn't be picking up the signal from the repeater, when I am able to pick up individual units on the repeater input that are equal or further distances away than the repeater.
 

M105

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I believe that the Dispatcher talks out on the RX frequency {repeater out}
That would be very strange since it would interfere with the repeater output. I can't think of any good reason a system would be configured that way and I doubt that is happening. Perhaps others have an explanation for your issues. A bad signal from the repeater transmitter to your location, either weak or distorted, is all that came to mind for me.
 

mmckenna

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Likely you cannot hear dispatch because they are using a wireline connection to the repeater.
-the radios in the field go through the repeater like you're hearing.
-dispatch console is connected to the repeater directly and just transmits.
This is pretty common for dispatch centers.

Are you 100% sure you have the correct output frequency? Where are you getting your information from?

If the repeater is doing 9600 NXDN on the input, it is EXTREMELY likely it is also doing 9600 NXDN on the output. I run a NXDN system (Kenwood) and I know of no way to do different NXDN modes on input and output.
If you are on the correct repeater output frequency, you should be seeing a 12.5KHz wide signal from the repeater. If you are not, there is something wrong with your programming, or you have some sort of local interference.
 

milo361

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Joined
Jul 12, 2007
Messages
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Location
Vernon/ Barton County MIssouri
Likely you cannot hear dispatch because they are using a wireline connection to the repeater.
-the radios in the field go through the repeater like you're hearing.
-dispatch console is connected to the repeater directly and just transmits.
This is pretty common for dispatch centers.

Are you 100% sure you have the correct output frequency? Where are you getting your information from?

If the repeater is doing 9600 NXDN on the input, it is EXTREMELY likely it is also doing 9600 NXDN on the output. I run a NXDN system (Kenwood) and I know of no way to do different NXDN modes on input and output.
If you are on the correct repeater output frequency, you should be seeing a 12.5KHz wide signal from the repeater. If you are not, there is something wrong with your programming, or you have some sort of local interference.
mmckenna,

Im fairly certain its the wireline connection. Most of the dispatch transmissions are only on the rx side of each repeater in the area.. analog or digital.

I got the majority of the information from the Kenwood NX-220 that I have here, which corresponds to the information on RR for Vernon County Missouri. It receives fine. If i get a chance ill snapshot what im getting from HDSDR the next time they talk.
 

milo361

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Joined
Jul 12, 2007
Messages
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Location
Vernon/ Barton County MIssouri
pic update

OK, so I have been able to take the screen shots. I have several. I had one time that I received majorly distorted audio from the rptr out freq. while the rest are just static. I also have one of the rptr in freq. showing what I receive when im able to decode.
Ive uploaded them to my google drive at :

https://drive.google.com/drive/folders/0B_3T3pfAYKe_TVpnU2w2NkJMblE?usp=sharing


Ideas?
 
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