SDS100/SDS200: Digital Trunking Distortion after Firmware Upgrade

[scanman1958]

I have had a SDS100 since 2018. I purchased the DMR & NXDN upgrades at the time of purchase. I never got around to upgrading any of the firmware updates over the years. About six months ago I decided to get all of the upgrades at once. I have always been timid around computers as I am very old school. 99% of the time I use the keypad for operating all of my scanners.

As luck would have it, I was successful in downloading the new firmware to my SDS100. No smoke. No fire. Here is what shows on the screen.

Main :version 1.23.05
Sub :version 1.03.05

Everything seems to work OK, as far as I know. However, I am having an issue with intermittent distortion on digital trunking systems. It doesn't sound quite like R2-D2 but if I could describe it...it would be if you saw pixilation on a TV screen and compare that to the sound that I hear. I had what I would say was perfect reception/sound before the update.

Would anyone have an idea as to what might be going on? Is there a filter or setting I now have to use with the newer firmware's?

Thanks to all in advance.

 

[nessnet]

The new firmware shouldn't have changed your filter settings.
It is possible it changed your receiver's sensitivity or decoding.
You'd have to give much more information (what system are you trying to monitor - and what antenna for instance) in order to get help here.

As to filters: they are entirely location / RFI dependent.
If you had good reception at the exact location before, it is highly doubtful filters would change anything.

Remember: in the analog days, it was static when a signal was weak.
Garbled DIGITAL transmissions are an indication of dropped packets, caused by low signal level or some kind of interference.

Edit your display to show RSSI and D-Error, which will give you (and us) more information on what is going on.

 

[n3617400]

You do not have the latest versions of the cpu and subcpu firmware installed.

 

[eaf1956]

• 1.03.06 Sub (7/11/2024)
• 1.23.07 Main (03/22/2024)

Current SDS 100 firmware

 

[scanman1958]

I short, I am scanning the Missouri MOSWIN system an the St. Louis County and Jefferson County SLATER systems. I am using a 800MHz specific antenna interchangeable with the stock antenna. Non of that has changed.

Even if I don't have the latest update, my issue began after I did the the updates. I have made no other changes to the scanner.

 

[scanman1958]

Update.

If I am correct, from memory, the rssi numbers should be as close to 0 as possible. Before my firmware update the numbers were in the single digits to around the 20's or so. Now the numbers are regularly in the 70's to the upper 90's. When the distortion happens the numbers jump into the 1-teens to 130.

I added the D-err to the screen and most of the time it's near 0 to about 6 or 7. When the distortion happens it jumps into the 30's, 40's and higher. I have seen it once over 100.

Not sure what is going on.

Again, thanks for any help.

 

[eaf1956]

I short, I am scanning the Missouri MOSWIN system an the St. Louis County and Jefferson County SLATER systems. I am using a 800MHz specific antenna interchangeable with the stock antenna. Non of that has changed.

Even if I don't have the latest update, my issue began after I did the the updates. I have made no other changes to the scanner.

When some people did the update before the latest one, some had issues and had to revert to older firmware. Then they came out with what is currently the latest firmware. You probably have the version that caused issues. SO either revert to what you had or get the latest firmware.

 

[scanman1958]

The last four updates had nothing to do with P25 digital distortion fixes so I am not sure how that 'might' fix my problem.

 

[eaf1956]

The last four updates had nothing to do with P25 digital distortion fixes so I am not sure how that 'might' fix my problem.

Even if I don't have the latest update, my issue began after I did the the updates. I have made no other changes to the scanner.

If they had "nothing to do with P 25 digital distortion" then why say it happened after updates?

Some people had problems with
Main :version 1.23.05
Sub :version 1.03.05

That was why 1.03.06 sub and 1.23.07 Main came out so soon.

 

[scanman1958]

Because in my original post I mentioned that I did all of the updates at the same time because I had never done an update for the five years I had had the scanner.

Jokingly....I am thinking it was a shock to the scanners system.

I'm still working on a plan. Thanks.

 

[eaf1956]

There are times when updating something in software/firmware that even though an area is not touched doing something unrelated causes issues with other areas.

 

[a727469]

So the question is, did you update to the current firmware? I missed if you said you are 100% updated. I did have the same problem mentioned with the older firmware but it cleared after updated to current. rssi numbers like 70-90 are excellent..I have never heard of an rssi number in the single digits. I have one site with rssi100+ and noise 50+ at times and still no distortion or break up. Also, many other factors could affect both rssi and noise. My numbers vary quite widely based on the day, weather etc and do bounce around, but maybe not as much as yours. Also, I am sure you checked antenna connection? If none if the above others will have to advise. Good luck!

• 1.03.06 Sub (7/11/2024)
• 1.23.07 Main (03/22/2024)

 

[scanman1958]

I am not up to date yet. I will do it soon. The antenna is good.

Maybe there is something in the newest update that isn't mentioned that could fix the problem. Thanks.

 

[Satcho]

scanman1958, I had a substantially similar problem except it was on my SDS200. TL;DR: set the Global Auto Filter to Off instead of Normal.

In January of this year, I was cleaning up my office and decided to move my SDS200 from its usual location on the window sill to my desk. I also updated the firmware to the 12/21/23 release (1.03.02 Sub / 1.23.01 Main). This release claimed improved digital reception performance and an updated filter for P25 Phase1, DMR, and NXDN among other things. After this physical relocation and firmware update, the audio would occasionally become garbled. I started looking at the RSSI and noticed that every few seconds it would jump from a baseline of high 90s to 110s/120s which corresponded to the audio distortion. Most of the systems I monitor are P25 Phase1 and in the 450/460MHz frequency range. There was static on a conventional system I added later and the RSSI would jump up in the triple digits as well. I assumed all of this was due to moving the scanner as I run the stock telescopic antenna. Several firmware updates later nothing changed. Just a few months ago I rearranged the office again and placed the scanner back in its original location. This didn't solve the problem, so I began searching for answers. I eventually used the Sentinel software to set the Global Auto Filter to Off instead of what I assume is a default setting of Normal. The RSSI is now consistently in the high 70s instead of high 90s and no longer jumps up every few seconds. Problem solved! I assume the SDS100 is similar in firmware and settings so you might give this a try.

​

 

[MotownJG]

Thanks Satcho for this idea. Trying it...

 

[scanman1958]

Thanks Satcho

Nearly 100% like my problems and "when" it started. Only difference is my P25 systems are 700/800. I also noticed the filter had been automatically defaulted to Normal. I also have set the filter to 'off'.. I am guessing that would be as close to the original stock setting...not having any filters.

I still have minor issues with monitoring "fringe" (distance) trunked systems that show the same rssi numbers. I am content with that being pretty normal. I live in a low spot in my city and have issues getting reception from beyond at least two spots with elevation at least 100' higher than where I am. A yagi and LMR400 can't overcome the situation.

 

[Ubbe]

I am guessing that would be as close to the original stock setting...not having any filters.

Uniden have named the filter settings awkwardly. Filter settings should be called Filter Offset. No offset are Off. Offset in one frequency direction are Normal and in the other direction is Invert. Wide are an offset only by halfway. Its the IF filter that change its 10MHz bandwidth up or down in frequency.

/Ubbe

 

[eaf1956]

And my 2 SDS 200's work best set to Wide Normal. It all depends on your local systems and conditions.