NJSP system question

[mdsxfire]

I use a uniden bc780xlt to scan our mutual aid VHF dispatch channels and occasionally the NJSP system. The other day I noticed when receiving a TG in trunk mode the transmission is “chopping” for lack of a better work in and out. If I flip through the frequencies of the system and catch a transmission it sounds fine, it only happens while in trunking. I’ve never had this issue and have had this scanner forever so I don’t believe I hit a setting without realizing it, but if anyone has had this or has a solution I’m all ears.
TIA


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[Skypilot007]

I still use one of the 780XLT on this system also. Good ole work horse radio they are.

Where in Jersey are you and which site(s) are you monitoring?

What you may be experiencing is one or two of the voice channel repeaters may be weaker than others from your location. The main simulcast systems for north, central and south have several transmitter locations for each.

So you may monitor a conversation and during this, the voice channel repeaters drop off at the end of a transmission. Then when the user keys the mic again they're on a different voice channel that has a weaker signal from your location. This will vary by location obviously. I hear this all the time on multiple scanners and subscriber type radios. Its perfectly normal.

If signals got really weak at your end you may want to check your antenna and feed line.

 

[GTR8000]

Its perfectly normal.

There's nothing normal about it. All repeaters at a given site should be extremely close to each other in output signal level and effective propagation. In other words, subscriber radios within the intended coverage area should never notice any distinct difference in quality between voice channels. If they do, then something is wrong.

Yes, there are slight variations due to factors like the use of multiple transmit antennas, slight nulls from the tower itself in certain directions, etc., but it should never be so noticeable that it negatively affects the signal quality when a subscriber radio is within the primary coverage area of that site or simulcast cell.

To be clear, I'm not disputing the premise that it doesn't happen from time to time, I'm simply saying that it's not normal and is indicative of a problem somewhere at the offending site.

 

[mdsxfire]

Here’s 2 videos, the first one is manually changing the frequencies just to get some traffic, the second is in trunk mode. On a side note I’ve had this system programmed in for a while with no changes and never had an issue. I also have an edacs system programmed with no issues.

https://youtu.be/_jsDnEMGtRQ


https://youtu.be/tWOJAQAD4Kw


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[Skypilot007]

I think there is something wrong with that scanner. Your signal strength even when its cutting out is good on the indicator. Mine has never made noise like that. Perhaps the system has been corrupted some how. Maybe try reloading the system into the scanner.

GTR8000, I stand by my statement above. The varying signal strength may not be normal for most systems but on the south simulcast portion of this system it is normal and has been for a long time.

 

[mdsxfire]

I think there is something wrong with that scanner. Your signal strength even when its cutting out is good on the indicator. Mine has never made noise like that. Perhaps the system has been corrupted some how. Maybe try reloading the system into the scanner.

GTR8000, I stand by my statement above. The varying signal strength may not be normal for most systems but on the south simulcast portion of this system it is normal and has been for a long time.

Yeah it’s very weird that the transmissions come in fine when not trunking, and the edacs system I follow also comes in without an issue


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[GTR8000]

GTR8000, I stand by my statement above. The varying signal strength may not be normal for most systems but on the south simulcast portion of this system it is normal and has been for a long time.

There's nothing normal about it, I don't care how long it's been like that. :roll:

 

[mdsxfire]

There's nothing normal about it, I don't care how long it's been like that. :roll:

Just to clarify I’m at the top of Middlesex county and have monitored this system for sometime with this issue just appearing the other day


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[GTR8000]

Just to clarify I’m at the top of Middlesex county and have monitored this system for sometime with this issue just appearing the other day

Yeah, I understand. I don't think what you're experiencing has anything to do with whatever Skypilot is trying to claim is "normal".

It's been many years since I've touched a 780XLT, so I'm a bit rusty. The first thing I would try is setting the system to FM mode instead of NFM, see if that helps.

There is also the possibility that you're experiencing some local interference. I would scan all of the North Simulcast voice channels in conventional mode during a busy period on the system, and note how each frequency is being received. More to the point, make sure the scanner is actually stopping on all of the frequencies to begin with. In your video it appears that the scanner is skipping over 858.4625, which is one of the frequencies that sounds choppy when scanning in trunked mode.

Note that not all of the North Simulcast frequencies are used all that often (such as 851.5625 and 852.2375), so concentrate on the ones that are used most often:

856.4625
856.9625
857.4625
858.4625
859.4625
860.4625

Make sure that the scanner is stopping on all of those frequencies listed above in conventional mode with good audio. I would even suggest holding on each of them manually for a few minutes to make certain the audio is good. If you have any issues with choppy audio on any of those, then you're dealing with a likely interference issue more than anything else. Or, a bad repeater at the nearest subsite, perhaps.

 

[Skypilot007]

There's nothing normal about it, I don't care how long it's been like that. :roll:

Good grief.....:roll:

 

[N2SCV]

Deleted.

 

[N2SCV]

Just to clarify I’m at the top of Middlesex county and have monitored this system for sometime with this issue just appearing the other day


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Check your PM's.

 

[mdsxfire]

So if I’m listening to a tx in trunk mode and it’s chopping in and out if I hit the trunk button and take it out of trunk mode it instantly stops going in and out and the tx is perfect. I wiped the scanner and started from scratch with no luck. Only think I can think of now is it’s using a different power supply, I don’t know why that would make a difference in only a moto 2 system when in trunk mode and not to every channel and edacs system but idk at this point


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