SDS100/SDS200: SDS200 Weird issue

[DurangoPursuit2019]

Your scanner show the signal strength of the control channel 774.34375 to be -82dBm most of the time but varies and can be -92dBm but the signal can also totally disappear. Any voice channels it tries to go to have no signal strength and it goes immediately back to the control channel.

This is typical for an interference issue that another transmitters frequency blocks the reception on a SDS scanner. That's why Uniden implemented the filter selections to their SDS scanners.

If you make a Hold on the System or Site and then go to Menu/Manage Favorites/"your FV name"/Review Edit System/ "your system name"/Edit Site and change the sites Filter setting then do Avoid to go back to the system or site Hold and see what happens, if the control channel stays at a steady signal strength and it gets reception on the voice frequencies. Try first the Off setting and then Normal, Invert, Wide Normal and Wide Invert one at a time and see if any of those will help.

If none of the filter helped then push the third softkey that sometimes are labeled Channel and enter 774.34375 and Channel button again ,although its label will not be displayed, followed by Function+7 to toggle IFX on. When you then select To Scan your system and site hold will be gone so you will have to do that again. Push the System button, wait 3 seconds and push it again and you then, within 2 sec, can turn the selector wheel to go between systems. If you wait too long between selections it will time out, then push System again and start selecting system within 2 sec but if you wait 3 sec after the System button push it will go out of hold mode.

When IFX On have been set to that specific frequency you only check what happens to the control channel using different filter settings, if it stays at a steady signal level. If that IFX helped then try doing that also to the voice frequencies if they still cannot be received with a signal strength.

/Ubbe

Could this still occur even on another site?

I stated the issue seems to be with Beaverdale specifically. I can pick up my countys TGs on the neighboring county's site, so I dont think the issue is interference related unless its something interfering with the tower and not my scanner.

 

[tvengr]

I have had a lot of good results using the Wide Invert filter on sites with 700 MHz frequencies.

 

[DurangoPursuit2019]

I have had a lot of good results using the Wide Invert filter on sites with 700 MHz frequencies.

Im using it on the Lee Co site which is 800, and it has improved my reception throughout my town and well out into the county even though im something like 30 miles from the towers on the far side of the county.

 

[DurangoPursuit2019]

Just want to give an update and show yall what I mean.

This is with the Lee Co site activated and held.

 

[ofd8001]

Yes, it stopped receiving our county aswell, which is what led me to replacing it thinking it was dying.

It worked perfectly up until it stopped, and now the SDS doesnt wanna work on the proper channel.

It makes no sense that switching to the neighboring counties site somehow makes it work.

It also makes no sense that ive got people telling me their scanners work fine, and others telling me they are having the same issues as me.

I was talking with a guy on the ISICS forums woth a 996P2 that said his was still working perfect, he sent me photos of the programming...identical to my P2. Yet somehow my P2 can't receive anything.

If there is something funky with the site, whether a programming issue with your scanner or something wrong with the site itself, you are describing the behavior I would expect. The scanner working on an adjacent site tells me the scanner itself has nothing wrong.

I tried getting on the FCC website to check the frequencies for the system/site. Unfortunately the FCC site is not working because of the shutdown. What I hoped was to discover was all the frequencies for the one site to suggest you program them, but alas.

Yeah, I'd be going nuts too trying to figure why this isn't working as designed. Rejoice and be glad you can still hear what you want to via an adjacent site.

30 Miles is a common distance for a site to travel, especially for a statewide system site. It probably getting close to the limit, though. Fortunately with digital, you either have it or you do not. Unlike analog, there is not static like signal falloff as you get farther away from a transmitter.

 

[DurangoPursuit2019]

If there is something funky with the site, whether a programming issue with your scanner or something wrong with the site itself, you are describing the behavior I would expect. The scanner working on an adjacent site tells me the scanner itself has nothing wrong.

I tried getting on the FCC website to check the frequencies for the system/site. Unfortunately the FCC site is not working because of the shutdown. What I hoped was to discover was all the frequencies for the one site to suggest you program them, but alas.

Yeah, I'd be going nuts too trying to figure why this isn't working as designed. Rejoice and be glad you can still hear what you want to via an adjacent site.

30 Miles is a common distance for a site to travel, especially for a statewide system site. It probably getting close to the limit, though. Fortunately with digital, you either have it or you do not. Unlike analog, there is not static like signal falloff as you get farther away from a transmitter

I am glad I can hear it trust me, since some of the people in the county can't hear it at all no matter what they do.

The thing thats actually driving me nuts is just that, why can some of us not hear it at all, why can some of us hear it just fine, and why am I the only one that can hear it off the adjacent site? The scanner community in my county is at a collective level of confusion and while its kinda funny its also extremely annoying 🤣

 

[Ubbe]

This is with the Lee Co site activated and held.

The control channel 857.9875 have a signal strength of -76dBm and the voice channel 855.2375 swings widely between -110dBm and 94dBm.

Another conversation using 855.7375 goes between -72dBm and -94dBm.

This is on the same site that should have the same signal strength for all channels but the scanner receives the site at a level between -72dBm down to -110dBm and it is impossible that they have designed the site to operate at such different signal levels. I assume when you are filming the scanner that your vehicle are standing still.

It's super helpful with these videos that show exactly what happens. But for digital systems the display of Noise are of no use in your Trunk Detailed display and you should instead replace that with Digital Error that are far more useful.

You should absolutely start experimenting with the scanners filter settings and try all of them once and then one time more with IFX set to all frequencies and write down what works best for each frequency.

Signal strength indicates the RF level of a wide frequency range that will include interfering frequencies so never use that when evaluating filters, use only digital errors as an indicator.

/Ubbe

 

[DurangoPursuit2019]

The control channel 857.9875 have a signal strength of -76dBm and the voice channel 855.2375 swings widely between -110dBm and 94dBm.

Another conversation using 855.7375 goes between -72dBm and -94dBm.

This is on the same site that should have the same signal strength for all channels but the scanner receives the site at a level between -72dBm down to -110dBm and it is impossible that they have designed the site to operate at such different signal levels. I assume when you are filming the scanner that your vehicle are standing still.

It's super helpful with these videos that show exactly what happens. But for digital systems the display of Noise are of no use in your Trunk Detailed display and you should instead replace that with Digital Error that are far more useful.

You should absolutely start experimenting with the scanners filter settings and try all of them once and then one time more with IFX set to all frequencies and write down what works best for each frequency.

Signal strength indicates the RF level of a wide frequency range that will include interfering frequencies so never use that when evaluating filters, use only digital errors as an indicator.

/Ubbe

For reference, the clips provided are using the Wide Invert filter already.

I have found out of all the filters it works the best. I'll change out the noise display next time im in the car.

How do I use IFX?

 

[tvengr]

How do I use IFX?

It is under the Miscellaneous tab in the Profile Editor of Sentinel.

 

[Ubbe]

For reference, the clips provided are using the Wide Invert filter already.

I have found out of all the filters it works the best. I'll change out the noise display next time im in the car.

How do I use IFX?

If none of the filter helped then push the third softkey that sometimes are labeled Channel and enter 774.34375 and Channel button again, although its label will not be displayed, followed by Function+7 to toggle IFX on.

It could be one if those times when there's always one frequency that interfere whatever filter are used. I have that happening at a crowded 462MHz range that no setting will help, either its a lower frequency or a higher one that interfere with reception. If you have the Waterfall feature, always usefull for the small amount it costs, you can probably see one or several strong transmitters in the frequency band. If it turns out to be more than 5MHz away it might be possible to use a $100 notch filter from PAR Electronics, if you have no other frequencies in the notch filters range that you wish to receive.

The attenuator feature in your scanner will have a 22dB attenuation at 800MHz and that will usually help a lot to reduce interference but then the received signal needs to be -80dBm or stronger so you could always try that. It is set for the whole site.

One tip, that I use, are to program that site twice with a different name and then scan both and make changes to only one site and use the other as a reference. You should be able to use the scroll knob to go between the two sites to do a comparison during a conversation, or set different quick keys to them.

When you finally have figured out the settings, if any at all will work, you can inform you local buddies what to use in SDS100/200.

/Ubbe

 

[dmfalk]

If none of the filter helped then push the third softkey that sometimes are labeled Channel and enter 774.34375 and Channel button again, although its label will not be displayed, followed by Function+7 to toggle IFX on.

Or, if your scan is on the affected frequency, hit the Channel softkey (as mentioned above) to simply hold the channel, then hit IFX, to see if it makes any difference. Sometimes, it does.

(And I'll second the waterfall recommendation, as a great utility to snoop out interference and adjacent signals!)

 

[Ubbe]

Or, if your scan is on the affected frequency, hit the Channel softkey (as mentioned above) to simply hold the channel, then hit IFX, to see if it makes any difference. Sometimes, it does.

In trunked systems the Channel button are for the current TG and not for doing a frequency hold.

/Ubbe

 

[DurangoPursuit2019]

Welp IFX has seemingly made no improvement...infact I believe it actually made it slightly worse.

 

[ofd8001]

How difficult would it be to take your scanner to one of the transmitter sites, like 1/4 mile and give it a listen? That may provide some additional clues.

 

[DurangoPursuit2019]

How difficult would it be to take your scanner to one of the transmitter sites, like 1/4 mile and give it a listen? That may provide some additional clues.

Depends which site you speak of. As im typing this im not a mile from the Lee Co sheriff's station(work nearby)which has a tower outside of it(unknown if it is one of the main simulcast towers though)

As for the Beaverdale site i can drive almost right up to it, I did just the other day.

 

[ofd8001]

The site that gives you the problem. Notice any differences when you were there?

That would help to rule out any external influences, such as de-sense, interference from other RF sources.

 

[DurangoPursuit2019]

The site that gives you the problem. Notice any differences when you were there?

That would help to rule out any external influences, such as de-sense, interference from other RF sources.

No, i drove past it twice with my scanner off of hold, and I was picking up transmissions from of all things courthouse security...but still on the Lee Co site.

As for the Lee Co site my reception is definitely better down here than in Burlington but thats a given. I still get the heavily fluctuating DBs either way.

 

[ofd8001]

I'm inclined to think this is a site issue. They may have added a control channel that is not listed in the database and thus programmed in your scanner. Or the site may have some technical issue keeping it from working properly.

As to why some receive and others do not, I can only speculate. Are they really receiving the site you have trouble with, or could they be on an adjacent site without realizing it?

 

[DurangoPursuit2019]

I'm inclined to think this is a site issue. They may have added a control channel that is not listed in the database and thus programmed in your scanner. Or the site may have some technical issue keeping it from working properly.

As to why some receive and others do not, I can only speculate. Are they really receiving the site you have trouble with, or could they be on an adjacent site without realizing it I'm leaning towards option 2 myself, but one of them sweats he only has Beaverdale programmed in, so idk

 

[werinshades]

So here's my take on all this. I noticed you don't have any Quick Keys programmed in, nor do I know how advanced you are on self-programming. It appears to me, you're getting another site or conventional frequencies since the P25 and Data symbols are disappearing when those frequencies come up. This would lead me to believe, they're not part of the site you're attempting to monitor or another "out of range sites" control channel frequencies have been added.

In Sentinel, Edit the Favorite List, pick your Favorite List, under Options drop box piick a Quick Key number. After that, under the System name in the right pane, scroll to the right and assign it a Quick Key. While under the same screen, in the left pane highlight the system. This will display additional fields and you can assign Quick Key's to Departments and if you click on the Site tab in the right pane, you can also add a Quick Ket to a site and review the frequencies. From here, I'd pick one site your close to to, cross reference the Control Channel frequencies only from the database, and delete any voice channels you added. This is where I'd start, and continue to modify as you go along.

As others mentioned, under the Site Option tab (not Global Filter), try the different Filters. I've watched a couple of your videos and see frequencies popping up that don't appear to be part of the site. When it sits on the site, it sounds good during the brief video. You might have added some errant conventional frequencies and if they're not assigned quick Keys, this is the behavior that's exhibited in my experience.