SDS100 Audio Muting Mid Transmission

[jmulvihill]

That is an analog system, so digital error count would be meaningless. NOISE would have some meaning, though.

One more from the other day that I forgot I recorded.

@3 seconds mute starts
@8 seconds mute ends
I noticed that in the last 2 seconds of the muting (Seconds 7-8) the noise jumps way up to 35K-40K, then drops down when the audio is unmuted.

SDS100_MuteOnly 030819.mp4

 

[jmulvihill]

That is an analog system, so digital error count would be meaningless. NOISE would have some meaning, though.

Last one, but it is a bit different. Early in my troubleshooting, I said that sometimes the mute delay was longer, but it always seemed to be in that 5 second range when I was listening. I got this longer 10 second mute on video.

@37 seconds mute starts
@47 seconds mute ends, but there is a funny clunk sound that may just be something in the transmission, but not sure
Also noticed that @46-47, Noise once again jumped up right before the muted audio returns....

SDS100_10SecMute 031419.mp4

Let me know if there is any other things that I can capture. All of my muting occurrences are just like these examples, and the staccato-like static is what you hear in the previously posted video, but the static can occur without the muting too. Just jumps in during the transmission.

Thanks

 

[peewee007]

I have the same issue - The muting problem seems to have been resolved in the latest firmware(edit: for me anyway) but that loud static noise still persists - I've tried to record a debug file to maybe point somethin out, but they're all being saved as blanks, following the directions found here

 

[teknishun]

You might have covered this before, but I was wondering. Are you by chance using CTCSS (tone squelch) on this channel?
If so, the interference on the channel could be so great that the tone is not being heard properly by the scanner and then
it will mute if there is no tone. Just a thought. The CTCSS won't necessarily display on the screen unless you customize the
display and give it a place to appear. I am especially curious about this since you mentioned it happens on 2 different
SDS100 scanners.

 

[teknishun]

Have you determined whether or not this issue is location dependent? Have you taken the scanner out of the house and
driven across town to another location and checked if the issue still exists?

 

[jmulvihill]

You might have covered this before, but I was wondering. Are you by chance using CTCSS (tone squelch) on this channel?
If so, the interference on the channel could be so great that the tone is not being heard properly by the scanner and then
it will mute if there is no tone. Just a thought. The CTCSS won't necessarily display on the screen unless you customize the
display and give it a place to appear. I am especially curious about this since you mentioned it happens on 2 different
SDS100 scanners.

I do not think that I am using CTCSS, but not sure where to validate that this is the case. I have looked through Sentinel menus and not found anything anywhere...

There is a field configured in the detailed display set for CTCSS, but I have never seen anything displayed in that area.

As for the 2 scanners, yes. 2 brand new ones out of the box. Bought one, had this issue, sent back for exchange and validated it is a different S/N, new replacement unit is doing exactly the same thing.

 

[KevinC]

One more from the other day that I forgot I recorded.

@3 seconds mute starts
@8 seconds mute ends
I noticed that in the last 2 seconds of the muting (Seconds 7-8) the noise jumps way up to 35K-40K, then drops down when the audio is unmuted.

SDS100_MuteOnly 030819.mp4

I'm no SDS-series expert, but noise figures that high would seem to indicate external interference.

 

[jmulvihill]

Have you determined whether or not this issue is location dependent? Have you taken the scanner out of the house and
driven across town to another location and checked if the issue still exists?

Yes, I have had the unit both closer and further from the transmission tower. But that was the original scanner and not with the new firmware. I doubt that it will make a difference, but will be able to validate this as I am going to town later this morning. I will have the scanner running and see what I can assess for the issue.

 

[jmulvihill]

I'm no SDS-series expert, but noise figures that high would seem to indicate external interference.

Kevin -

I would agree, but that noise value comes at the END of this mysterious muting issue. When the scanner mutes, and the noise is not high, and it then waits the 5 seconds during which the noise values are not really bouncing up. The high noise value seems to only come in at the point when the scanner is unmuting.

Something has to be triggering this mute to start, and if it were this noise causing it, I would expect to see it when the muting happens. But as I have said before, I am, NOT a guru, rather just trying to apply my logic gained from my computer programming days... I may be WAYYYY off base if similar logic does not hold true in the SDR/SDS world of firmware.

 

[jmulvihill]

Does squelch come in to play once the transmission has been locked on to? Just reading through things, trying to see if there is a setting that I have set incorrectly. I am at a squelch of 2 now, but may play with it later just for grins. If it is guaranteed to not have any impact, I will save my energy... ;-)

Also, anyone know the answer to the SYS ID question I asked earlier? While ID Scanning this Motorola system, I get the Sys ID of 4227h displayed maybe once every 2-5 second (it blinks up in the Sys ID field). When locked on to a transmission, sometimes it is there, sometimes it is not... I notice on the digital system, those fields are usually populated for every transmission. I assume that this is just a difference between analog and digital system, in that the analog system only transmits this Sys ID every so often...?

Thanks all!! I really appreciate all of the input, suggestions and feedback.

 

[jmulvihill]

So a quick update. I have made a few changes to my settings, and seem to be having improved results for the last hour since making the mods. BUT, I have no idea WHY the changes would make any difference, so wondering if this is just luck and things will be worse again later, which could point right back to interference that may not be starting until people get to work and start keying a radio transmitter somewhere more frequently...

The first change that I made was the Modulation setting for the Collin Cty system. It was set to AUTO, but I set it to NFM as that is what is always displayed when a transmission locks on. I asked about this before, and was told AUTO is fine, but want to see what would happen, as this was the only system with modulation set to AUTO... Stab in the dark #1....

The second change was to go through ALL favorite lists and change the filters from Global to Off. These were for FLs that were not active, but I wanted to get them all set the same way. Should have zero impact... Stab in the dark #2...

Going to play with squelch here today... It is set at 2 now, but may try upping it to 3 if the mute issue returns... I think this should have NO impact, but I will look to the others here to chime in... Stab in the dark #3...

More to come later. Heading to town now...

 

[phask]

Setting to 3 should be worse.

Global filter would set for whatever you have set for Global (if any) , you might try all the filter settings for that system.

In theory, setting from Auto to NFM might help, it sure does not hurt.

The noise issue is the root of your problem, whether it's something internal to your home, outside and local or general may be difficult to determine.

You do need to get somewhere away and see what the difference is.

FWIW - noise can be from literally dozens of items, computers, Smart power meters,gas meters, routers,etc. It seems to be something cyclical, but that is undetermined.

 

[jmulvihill]

Setting to 3 should be worse.

Global filter would set for whatever you have set for Global (if any) , you might try all the filter settings for that system.

In theory, setting from Auto to NFM might help, it sure does not hurt.

The noise issue is the root of your problem, whether it's something internal to your home, outside and local or general may be difficult to determine.

You do need to get somewhere away and see what the difference is.

FWIW - noise can be from literally dozens of items, computers, Smart power meters,gas meters, routers,etc. It seems to be something cyclical, but that is undetermined.

Phask -

I just got back from town. I am still having the issue, but not nearly as often as before. So not sure if this is just luck and it will return here later based on some external noise source, or if one of the afore mentioned settings has provided improvement. After changing the settings, I had only a single occurrence here at my home in the first hour, and on my approximate one hour trip down to town 25-30 miles away, its happened once for sure, but maybe twice as I couldn't look at the display one time when a transmission sounded like it may have been cutoff.

Either way, having 1 or 2 mutes per hour will be a VAST improvement if it holds long term... Just have to wait and see. I hope @UPMan can chime in as to whether there is anything in the SDS firmware that changes in these settings could provide relief in the muting problem.

Thanks all!!

 

[UPMan]

The high noise indicates an interfering signal. One of my beta testers happened to be in Collin County yesterday, and monitored the system with no issues, obviously from a different location.

AUTO simply sets modulation to whatever the default is for the band (which is NFM), so setting to NFM should only have a placebo effect.

I would try turning on attenuation, then retrying each filter setting. If you had an SDR dongle, you might be able to monitor a swath of spectrum and see when the offending signal appears (you'd see a spike on the spectrum monitor concurrent with the interference). Knowing where in the spectrum the signal is relative to the target frequency might open other possiblities. Or, you might be able to re-orient your antenna to minimize reception of the interfering signal.

Also, engineering noted that, since you are monitoring from an FL, you should confirm that all the channels are set for Analog (which would be the default if you moved the channels from the main database, but not if you programmed them by hand).

 

[jmulvihill]

The high noise indicates an interfering signal. One of my beta testers happened to be in Collin County yesterday, and monitored the system with no issues, obviously from a different location.

AUTO simply sets modulation to whatever the default is for the band (which is NFM), so setting to NFM should only have a placebo effect.

I would try turning on attenuation, then retrying each filter setting. If you had an SDR dongle, you might be able to monitor a swath of spectrum and see when the offending signal appears (you'd see a spike on the spectrum monitor concurrent with the interference). Knowing where in the spectrum the signal is relative to the target frequency might open other possiblities. Or, you might be able to re-orient your antenna to minimize reception of the interfering signal.

Also, engineering noted that, since you are monitoring from an FL, you should confirm that all the channels are set for Analog (which would be the default if you moved the channels from the main database, but not if you programmed them by hand).

I was down in McK ~30 miles away this morning and still had the issue, just not as often as yesterday and prior times. Today has been better after the mentioned changes.

I figured as much WRT the Modulation AUTO setting changed to NFM, but I was just trying to outline what I had changed prior to seeing better performance.

I have already tried turning Attenuator ON and cycling through the filters. There was no appreciable difference.

As for the SDR dongle, I have no clue what that even is. I will have to research, but I don't have one of any SW for spectrum analyzation. As for the interfering signal, what I have seen for the Noise increase is that it comes at the end of this muting issue, so I am not sure how that correlates to some potential noise source causing the muting to engage. Wouldn't the noise spike happen and then trigger the "XYZ" algorithm that is causing this muting in the firmware?

As for the FL, yes, I downloaded from the main database, but I have also confirmed that all of the TGIDs are set to analog but for one. The System is set to Motorola. There is one TGID in the Sheriff department (Narc/Vice TGID 1424) that is shown as digital (and encrypted from the RR database), so I have that TGID set to Avoid.

 

[UPMan]

I'm not sure if NOISE responds immediately...there could be some latency between onset of noise and the change in noise figure. I'm sure my engineers will tell me, later (they are in Tokyo).

SDR dongles are cheap ($30, for example) USB dongles that plug into a PC. Then, there is free software that allows you to use them as a radio receiver and/or spectrum viewer. The inexpensive ones give you about a 2MHz "window" into the spectrum. More expensive ones allow for a wider spectrum view. (And, even more expensive ones will transmit as well as receive.)

 

[AKJohnny]

The only commonality between being home and 30 miles away is you, the scanner, and your smartphone. For giggles, have you turned off your phone while testing? Just a long shot.

 

[jmulvihill]

The only commonality between being home and 30 miles away is you, the scanner, and your smartphone. For giggles, have you turned off your phone while testing? Just a long shot.

I actually forgot the phone at home, so it was out of the equation too....

 

[jmulvihill]

I'm not sure if NOISE responds immediately...there could be some latency between onset of noise and the change in noise figure. I'm sure my engineers will tell me, later (they are in Tokyo).

SDR dongles are cheap ($30, for example) USB dongles that plug into a PC. Then, there is free software that allows you to use them as a radio receiver and/or spectrum viewer. The inexpensive ones give you about a 2MHz "window" into the spectrum. More expensive ones allow for a wider spectrum view. (And, even more expensive ones will transmit as well as receive.)

It will be interesting to see if there is a 5 second latency in the Noise display. If so, then it could what is happening...

 

[Ubbe]

If you set a filter to global it means that it uses whatever setting you have set for global in the profile. It's an easy way to set a filter from one place that will change filter settings on all sites and conventional departments that are set to global. Change the filter setting in the profile to different values to test and if you have a receive signal strenght of -80 or stronger, I.E. -70 -60, you could use the attenuator.

As the mute sometimes last for 10 second you could try and quickly change the squelch to 0 when the mute happens to see if you hear just noise or perhaps an interfering signal.

/Ubbe