SDS100/SDS200: No DMR Transmissions Being Received

[rkillins]

Would anyone like to contribute some troubleshooting tips for me to figure out why my SDS100 isn't picking up DR or NXDN transmissions? I am monitoring both a DMR Con+ system and a NEXEDGE 4800 system, but neither our picking up transmissions despite hearing transmissions from those systems on my DSD+ setup. If I use the Analyse function > System Status, and select the system (DMR as programmed into my SDS) and site (same as tuned to in DSD+) and S every once in a while blips (3-4 bars) and network ID and site ID don't appear to ever populate (they did briefly, but not since)

I have purchased both DMR and NXDN plugins from Uniden. Is there a way to tell if they are installed (they were at one time as I had no problems hearing these systems a while ago). If I go to the Upgrade section the menu lists only options to upgrade. I'm unsure if the option remains in the menu even once installed, or if it is removed.

 

[dave3825]

Uniden does not sell plug ins. Go into your menu and scroll to where the dmr and nxdn are and look there. If it’s asking for the code, it’s not activated. Do you remember entering in the numbers you received with your upgrades?

 

[rkillins]

Plugins, updates whatever. Yes, I do recall entering the numbers in the past, and as mentioned, was able to monitor DSD and NXDN systems in the past. Says it's already been activated. Must be just crappy reception (I don't have good reception with my SDS, too much nearby tower interference).

 

[Whiskey3JMC]

I have purchased both DMR and NXDN plugins from Uniden. Is there a way to tell if they are installed (they were at one time as I had no problems hearing these systems a while ago).

Press menu key. Navigate to Settings (Press E) > Upgrade (E) > Scroll to each applicable upgrade (E) If upgrade is activated the screen will tell you so

 

[dave3825]

was able to monitor DSD and NXDN systems in the past.

Does DSDPlus have any issues monitoring those said systems now? What antenna is your dongle using and what’s the scanner using?

 

[rkillins]

Thanks folks. @Whiskey3JMC, did that and it checks out that they are activated.
@dave3825, DSD+ has no issues with either of these systems, coming in nice and clear. The antenna on the dongle is simply the telescopic dipole that came with the SDR. I don't even have it set at the correct length for the frequency band of these systems. I could do better, but it's giving me the satisfaction for what I set out to do. The SDS is using an AEcreative Wide Band Scanner Antenna (Amazon), which I heard was no good ... but again, it was proving to be satisfactory.

 

[dmfalk]

And just to check, make sure you can receive your regional NOAA Weather Radio stations, so we can eliminate this issue (a break in the antenna feed).

Now, on to the subject at hand: the upgrade keys. One, Sentinel doesn't store them, nor does it even know you have them. These are entered and stored directly on the unit, normally never to be overridden by firmware upgrades, etc. Once you've entered them, they're there to stay. There is no interaction between the Uniden website and the scanner, except for firmware and database upgrades.

 

[rkillins]

Whew. Weather locking on 162.550. (as well as a handful of railroad freqs).

 

[dave3825]

DSD+ has no issues with either of these systems, coming in nice and clear.

The antenna on the dongle is simply the telescopic dipole that came with the SDR. I don't even have it set at the correct length for the frequency band of these systems.

The SDS is using an AEcreative Wide Band Scanner Antenna (Amazon), which I heard was no good ... but again, it was proving to be satisfactory.

Try the antenna from the dongle on the SDS. Is still no go, then I would start checking the programming in the SDS

 

[Ubbe]

(I don't have good reception with my SDS, too much nearby tower interference).

Yes, that can be a major issue with the SDS100. Try different filter settings and also to enable IFX to the control channel frequency to see if any of those settings will improve reception.

I would recommend to enter the control channel frequency directly on the scanner. Push Channel button to stop scan then enter the frequency followed by the Channel button again.

Now you can do function+7 to toggle IFX on ond off. Try both setting with each filter.

To change filter go to the scanners menu, scroll down to Srch/CloCall Opt and in there you have the different filter settings. Select one of them and then push the Avoid button to come back to the frequency display and see if decodes the data signal any better.

It will help if you configure the display to show bit errors. Go to menu and scroll down to Display Options and select Customize and scroll to Set Search/CC Mode. With the scroll you can go 5 rows up from the bottom and change a field by pushing E or the top of the scroll knob and chose Select Option Item and E and scroll to Digital Error Count and confirm by E. Push Avoid button to come back to the frequency display.
You would like to have as few errors as possible.

/Ubbe

 

[rkillins]

I'm honestly unsure what to expect.
I entered the control channel frequency and it picked up the signal that I could hear audibly, although it was pretty weak and statiçy. I enabled IFX and the audible burr of the control channel ceased. The display did however begin to flash the color code and flash between Slot1 and Slot2. The network ID was displayed with an RSSI level around -103dBm. I will either hear the signal,or seethe display react, but usually not both. The display has stopped now with IFX off, but I have audio. Turn IFX on again, I have audio, RSSI indicator but no color code or slot indicators.

I really suspect it has to do with my antenna and or the antenna connection. I wiggled the connector (there was no play),and the audio stopped and the display started showing detail again. I tried different antennae with similar or worse results. One antenna I used picked up nothing unless I was holding onto the antenna. I switched out the BNC adapter and no noticeable difference. I'm trying to find the stock antenna to eliminate the adapter, but the poor antenna likely isn't much better than a better BNC based antenna with adapter.

I,m Leary to start playing with filters until I know what I should expect from the configuration. Am I seeking audio or no audio combined with the display. I'm assuming seeing activity on the display is good in that that the channel is being decoded.

 

[dave3825]

The filters are in the scanner and can be turned on or off very easily. You can decode a cc and have no audio on weak and distant signals.

If you drive, take the scanner closer to the system your trying and if the scanner works than your either to far or the antennas are not up to par.

 

[Ubbe]

an RSSI level around -103dBm.

That's pretty much the lowest level of signal that can be decoded. It will be a very noisy signal from an analog transmission and very difficult to decode if digital.

If you look at that bit error value it will have decode issues if it goes up into the 7-10 range. It usually works fine with 5 or lower.

The RSSI value can go worse if you have strong transmitters at other frequencies as the scanner has an RF level sensor that works over a wide frequency range that will reduce its receiver gain if it sense a strong signal. Also the RSSI detector works over a wider frequency range and not just from the frequency you are monitoring, so go only by the bit error value when trying different things to improve a digital reception.

/Ubbe

 

[rkillins]

Thank you!

You can decode a cc and have no audio on weak and distant signals.

So ideally, one would want to both hear the control channel, and see decoding activity on the display?

If you drive, take the scanner closer to the system your trying and if the scanner works than your either to far or the antennas are not up to par.

Sounds like a plan. There are three sites for this system within 10 miles of where I am. The closest, in my city, appears to be offline (or RR has incomplete data) as unable to find any control channel for it.

If you look at that bit error value it will have decode issues if it goes up into the 7-10 range. It usually works fine with 5 or lower.

Yeah, I am getting 5 - 40, most reports on the higher end.

 

[dave3825]

So ideally, one would want to both hear the control channel, and see decoding activity on the display?

You don't actually want to hear the cc unless your just programming it conventionally to see if you can receive it in general.

With reception issues, it can decode and display system info like slots, color codes rid's etc but not have enough signal to decode and produce audio.

 

[rkillins]

Interestingly, I connected the antenna from my DSD+ setup (see post #6), and had the worst results. The portable antenna actually out performed (loosely) what is giving me success with my SDR setup. Not receiving any targeted (DMR Con+ CC). I haven't made it out closer to the tower to see what signals are like.

 

[rkillins]

Took a drive out to the site and locked onto the CC frequency (direct entry) of the Con+ system I'm struggling with. No audible CC heard (based on @dave3825 's comment in post 15 I'm wondering if I should have - perhaps I'm misunderstanding) but 0 errors and a decently low RSSI for what that's worth. So, chalking this up to being just too weak a signal to get to my SDS 10 miles away. A second site in this system is 10 miles from me in the opposite direction, with similar qualities. This system does have a site listed in my City, right in between the two active sites, but it appears offline. I'm sure if I that site was active I'd be in a better position.

 

[dave3825]

This system does have a site listed in my City, right in between the two active sites, but it appears offline. I'm sure if I that site was active I'd be in a better position.

Its always possible there could be a control channel not labeled properly or even missing from the database. You could try clicking on the site, and look for any FCC licenses. Then see if there are freqs on the license that are not listed in the db.

 

[rkillins]

Yeah, I looked it up in the government records (Canadian TAFL) and that site location only shows those same frequencies that RR has referenced. Would DSD+ identify a neighboring site if it wasn't active (ie no CC)? I'n not sure if DSD+ uses past data to populate info, or if the CC carrier being monitored broadcasts neighbouring information, and if so, would it broadcast only "online" neighbours?

 

[dave3825]

DSDPlus will announce any neighbor info that's coming across the cc your on. It will list the site but not sure on DMR what it does if the neighbor site is offline.