NXDN Call Dropouts

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VE3SCP

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I monitor a very active UHF NXDN48 system consisting of 20 frequencies with very close channel spacing of 6.25 kHz. 20-30 percent of the transmissions drop out mid stream. You will hear someone talking and then part way through a word it drops out just like they un-keyed the mic. If the radio transmission is long enough it might pick up the conversation again but most times by the time scans back around the 20 frequencies it is lost. You can see this happen when viewing with Control Demo software as well.

I have not been able to determine why or what causes this. If I monitor this same system with DSD+ and SDR radio's there are no drop outs. It only appears to happen on the scanner. I use the same antenna on both the scanner and DSD+ through a distribution amp so everything that way is identical.

Has anyone else noticed this happen?
 

sibbley

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Have you upgraded to latest firmware? For me this was a problem till latest firmware update around January 20 or so.

If you did update, contact Whistler support via email.
 

trentbob

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So before the latest update "fix" this was happening for everyone exactly as you described it. For my UHF system with 23 frequencies it is working properly now. I found that programming it manually without using the software except for Alpha tags after the talk groups were put in seemed to work better. My City's Fire and Police Department are not in the database and I was having some missed replies and guessed that it was a few missing frequencies and it was. I did the FCC database research and added the two frequencies. The frequencies have to be put in order. You might also want to manually change your low threshold to 50% and high threshold leave at 95%. Also manually change your dwell time to 2.0 seconds. Of course there is the obvious to make sure that you have the 2nd nxnd update. Having an outdoor antenna or being very close to the system will make a difference. Of course the radio is useless for The p25 Phase 2 simulcast system in my County and the only use I have for the radio is the nxnd and I must say it does work well in the same kind of system that you have.
 

VE3SCP

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Thanks for the responses.

Yes I am running the latest firmware update and I have sent a ticket to Whistler support. They did respond initially with more questions but then stopped responding to further e-mails after I provided more information.

I have not manually programmed the system but I will try this. I usually use the software.

I have adjusted the dwell time several times from default to 3-4 seconds with no change. I did adjust the thresholds but not that low - I will try that. The antenna is mounted outdoors feed with 9913. I have also been mobile and been in sight of the tower with same results. This system has many other sites located at different locations miles a part and all locations do the same thing.

Oddly enough there is a NXDN96 system on the same tower. This system works fine.

Maybe I am the choosen one and it only affects me lol..
 

trentbob

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You may have just identified your problem. What frequency range is that other nxnd system that is on the same Tower as yours? There have been reports of your problem happening when being very close to a tower using frequencies close to yours or even in some cases with DMR or trunked systems using some of the same frequencies. Just a thought. It would not make a difference with the professional subscriber radios used within the system but might affect your scanner not unlike professional subscriber radios not having a problem with LSM where Whistler scanners do.
 

VE3SCP

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They are both UHF but the troublesome system is UHF Lo Band (422) and the other system UHF High (453). I would have thought it would affect the DSD+ and SDR radio set up as well but it doesn't.

Other neighbor sites which are located over 100 miles away suffer the same fate.
 

troymail

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So before the latest update "fix" this was happening for everyone exactly as you described it. For my UHF system with 23 frequencies it is working properly now. I found that programming it manually without using the software except for Alpha tags after the talk groups were put in seemed to work better. My City's Fire and Police Department are not in the database and I was having some missed replies and guessed that it was a few missing frequencies and it was. I did the FCC database research and added the two frequencies. The frequencies have to be put in order. You might also want to manually change your low threshold to 50% and high threshold leave at 95%. Also manually change your dwell time to 2.0 seconds. Of course there is the obvious to make sure that you have the 2nd nxnd update. Having an outdoor antenna or being very close to the system will make a difference. Of course the radio is useless for The p25 Phase 2 simulcast system in my County and the only use I have for the radio is the nxnd and I must say it does work well in the same kind of system that you have.
:confused:

What UHF system are you referring to? I see a 26 frequency 700mhz system in Bucks County. Assuming (maybe you said it) this system isn't in the database, can you advise the FCC license info?

I'm just curious - trying to make sure we're not mixing apples and oranges here.

BTW - for NXDN and DMR (for Whistler), the frequency order does not matter.

EDIT: I'm also curious because of another thread that is talking about the EZ Scan software possibly not programming radios properly (sounds like you're saying manual programming is working better here also). Again, just curious.
 

DonS

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If system channels are truly spaced only 6.25kHz apart, have you set the system's sites to use "NFM"? If not, the scanner is using a wide filter and adjacent frequencies will have an effect.
 

cobraDIHO

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Is it possible that the system you're monitoring is using non-standard pairs (3.125 kHz splits from the center frequency)? Some NXDN systems are notorious for this and the average scanner's selectivity may not be able to handle it very well.
 

VE3SCP

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The system I am monitoring is in Ontario Canada, It is called OnQue and has multiple sites.

Yes the scanner is set to NFM. I made sure of this due to close channel spacing. I have also monitored 3 frequencies side by side come on line at the same but did not seem to cause an issue. This is what I first thought the problem was.
 

VE3SCP

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I should have also stated it is in RR as Toronto area. Trunked system and the site is CN Tower.
 

WhistlerWendy

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Thanks for the responses.

Yes I am running the latest firmware update and I have sent a ticket to Whistler support. They did respond initially with more questions but then stopped responding to further e-mails after I provided more information.

Hi VE3SCP -
I'm sorry you are having issues with NXDN but it sounds like everyone here is getting you fixed up.
I apologize if you had less than stellar customer service from us here at Whistler. If you are still having issues, please send an email to support@whistlergroup.com and I will personally make sure we get you fixed up!

Happy Scanning!
Whistler Wendy
 

VE3SCP

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Hi Whistler Wendy.

I am certainly not complaining or upset about the technical support. They did respond right away with some questions which I replied to. This happened on a couple of occasions. It is possible they didn't have an answer or are looking in to it. I apologize if I gave you the impression it was poor response.

I can not even rule out other issues other than the scanner causing the issue at this time. I am merely trying to see if this is an isolated case or not. Your quick response to this post proves yet again the great customer service from Whistler - thank you.

This is great forum with people trying to help people.... Thank you everyone.
 

trentbob

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Troymail... we're not confusing two systems. The Bucks County system you saw which is Phase 2 700 megahertz simulcast may work for a few people in the county in a fixed position if they live in the right proximity to a tower and jump on one foot with a tinfoil hat on but otherwise Whistler scanners do not pick up the Bucks County system or any other p2 simulcast system I've tried especially in a mobile or portable situation while you're moving in between Towers. This is a well-known fact in this heavy LSM area even though I think there may be some exceptions where people say picking up four words out of 10 is better than nothing. Not in my business it's not. Uniden scanners do pick it up in some locations but it's muffled and garbled with poor performance. Media types like myself use a apx7000 to dependably pick up Bucks County. The nxnd system I monitor is 4800 in the 460 range non type D. The frequencies are not listed under the city's name in the FCC database on purpose which I guess is a topic for another thread LOL. Good luck to the OP in Ontario... keep trying to figure out the puzzle. You've got some good people listening to you here and you might solve the problem yet... Bob.
 

WhistlerWendy

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Hi Whistler Wendy.

I am certainly not complaining or upset about the technical support. They did respond right away with some questions which I replied to. This happened on a couple of occasions. It is possible they didn't have an answer or are looking in to it. I apologize if I gave you the impression it was poor response.

I can not even rule out other issues other than the scanner causing the issue at this time. I am merely trying to see if this is an isolated case or not. Your quick response to this post proves yet again the great customer service from Whistler - thank you.

This is great forum with people trying to help people.... Thank you everyone.
Ok great! We have a few people on vacation so I just wanted to make sure someone didn't leave you hanging.
 

slicerwizard

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VE3SCP

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I have also noticed that on 2 on the system frequencies I have background static. The static is on 422.4000 and 422.40625. The static is present with no antenna and with a 50 dummy load on the antenna port. The static (birdie) will squelch out if when the squelch knob is set 50-60%.

These 2 channels are predominately worse for drop outs but it does happen on other frequencies as well.

Does anyone else hear this noise on those frequencies when programmed in conventional mode?
 

theTastyCat

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OP, I'm having the same issue. Was monitoring NXDN conventionally tonight very close to the site and had more than one perfectly good signal just drop right out, only come to back 2-3 seconds later. I've also got a ticket in to Whistler for NXDN troubles - will report back what happens!
 
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