SDS100/SDS200: Filter problems with no resolution..

[trentbob]

I’ve monitored the CO DTRS in Northern Colorado with SDSx00 with default filters. I have seen where some get better results in Colorado with wide normal - but as you know, the filters are location dependent. However, It sounds like your issue is something that the filters do not address.

Let me throw some questions out for you to consider :

What version of firmware do you have installed?

What happens when you take the SDS100 outside? (Are you suffering from local interference or inside your residence?)

What happens if you take the scanner closer to one of the sites? To the town the site is nearest to? (Does it improve with a stronger signal?)

Are there any cell towers nearby? Other possible sources of interference?

Are other settings set at the factory default? (P25 thresholds, etc)

What sites in Bent County you focusing on?

Finally, thank you.

 

[chad_96]

I’ve monitored the CO DTRS in Northern Colorado with SDSx00 with default filters. I have seen where some get better results in Colorado with wide normal - but as you know, the filters are location dependent. However, It sounds like your issue is something that the filters do not address.

Let me throw some questions out for you to consider :

What version of firmware do you have installed?

What happens when you take the SDS100 outside? (Are you suffering from local interference or inside your residence?)

What happens if you take the scanner closer to one of the sites? To the town the site is nearest to? (Does it improve with a stronger signal?)

Are there any cell towers nearby? Other possible sources of interference?

Are other settings set at the factory default? (P25 thresholds, etc)

What sites in Bent County you focusing on?

Thanks for the reply,

So, obviously I'm on the southeastern plains (flatlands). there is no happy medium in any filter. Wide normal, etc...I'm constantly finding that I can rifle through the filters and each one ( minus off and normal) work.

-I've taken the 100 outside, Same results. Just better RSSI.

-also, tried sds200 inside with outdoor mag mount antenna on top of metal roof. Which I should say isn't as high as the actual attic. Area. Same problems.

- no towers nearby of any kind. Rural area. Honestly, if any type of antennas (maybe 2-3) same I'd not more distance away.

-other settings? Not sure. Not that I'm aware of.

-sites are fort lyon Correctional (main site) and La Junta site. Both are what's needed.

Honestly, maybe I should just get a discone antenna for 800mhz and put it in my attic. That's my highest point without having it outside and needing the added grounding and mast issues? What do you think?

 

[RMason]

What version of firmware do you have installed?

What range of D errors are you seeing?

What happens if you take the SDS100 closer to one of the sites? To the town the site is nearest to? (How much does it improve with a stronger signal?)

 

[RMason]

The other thing that gets me is I get better RSSI and D-Errors on the site that is further than my main site

I assume that you are getting better RSSI/D-Errors on the LaJunta (distant) site than on the Fort Lyons (local) site.

The LaJunta tower is higher and has more power than the Fort Lyon tower. This will contribute to better reception from LaJunta even though it is further away.

The Fort Lyon tower is only 30’ high and has ERP of 177W.
The LaJunta antenna is 122’ high and has ERP of 212W. In addition, the LaJunta site is 100’ higher than Fort Lyon - so the antenna is about 190’ higher at LaJunta with 35 W more power (if you believe the license info).

 

[Ubbe]

So explain this Ubbe, of the OFF positon is what other uniden models use. Why the **** would I need another model instead of the SDS series???? Why not just put it to the off position, Einstein? Then I'm using any other model, as that is what other models use? Explain yourself...

SDS scanners use a 75 cent receiver chip (that replace components used in other scanner of perhaps 10 dollars) that are intended to be used in satellite receivers and TV receivers are not all all suitable for wide dynamic signal levels that exist for police scanners. The receiver has a huge amount of false frequencies that mix inside the receiver so that one received frequency will pop up at hundred other frequencies. SDS100.mp4

During beta testing it was apparent that the receiver was not good enough but Uniden had already decided to use this cost saving solution, that also makes it possible to properly receive simulcast systems. They had made less profit from all the recalls and free service of bad displays and clock circuits in the prior 436/536 scanners and wanted a boost in profit. To solve this reception problem without replacing hardware with a more costly one they opted to use a technique that are used in HAM radios called IF shift.

One filter for the IF frequency are 10MHz wide, narrower ones are much better but also more expensive, and the received signal are at most 0.025MHz wide. That wide filter are no issue for "normal" scanners but the SDS receiver are so poor that it becomes a big issue if you have interferencies.

Those filter settings are always using the same 10Mhz filter and in its Off setting the received signal are in the middle of that 10MHz window, receiving all kinds of other radio signals within a 10MHz spectrum around the received frequency. When you select different filters it only change the oscillators in the receiver so that the 0.025MHz received signal moves from the center of the filter and more to the edges of it.

The theory are that if you receive 850MHz in the middle of the filter then another transmitter at 855MHz will get thru the filter and create interference in the receiver as the filter are +/-5MHz wide, but if your received signal are changed so it will be at the edge of the filter, 1MHz from the high frequency edge and 9MHz from its lower edge, then that 855MHz at +5MHz will be outside of the filters range and will not slip thru it. The problem then are that you might have interfering signals 9Mhz lower in frequency that then instead will go thru the filter and create havoc in the receiver.

It all depends of your unique local RF situation. Some people say that SDS scanner are bad analog scanners but it is the exact same hardware used in digital, but in digital you don't notice the problem as much as you either hear the digital conversation or you don't and you are not really listening to interferences as you are doing in analog mode where you are hearing the "raw" signal and not a decoded data signal.

The recommendation from Mr. Opitz to choose another scanner model came from his knowledge of the flawed received used that would not perform as well as "normal" scanners but are the only choice if you want to receive simulcast systems.

SDS scanners has the same functions and features as the 436/536 but with the added simulcast capacity, so if you don't need that then a 436/536 scanner would be more suitable. Uniden left out all technical specs in their user manual for SDS scanners, as that might be used against them in US where people sue companies but in the EU the manual have all specifications of the receiver.

/Ubbe

 

[a727469]

"The late Paul Opitz, the scanner guru at Uniden, said that if you don't have simulcast issues then you are probably better off using another scanner model." ..as quoted by @Ubbe

So explain this Ubbe, of the OFF positon is what other uniden models use. Why the **** would I need another model instead of the SDS series???? Why not just put it to the off position, Einstein? Then I'm using any other model, as that is what other models use? Explain yourself...

Is this the type of b.s. weinershades told me you spew out to people? I believe the direct quote was.." Ubbe gives a lot of false and bad information, and doesn't even live in the United States."...

So, why I did my duty of paying for a membership, that I didn't have to, I get the conflicting bull**** opinions of other members. Or is it that when the members who claim to know their ****, cower down when they don't know an answer and have to much pride so they give the rhetorical "figure it out, read, research," type answers?

Honestly, many company's recommendations say RR for help, database, etc.. just to be led to "pros" who give conflicting answers and belittle people. Gtfoh..

Pardon my intruding on a situation where people are trying to help you…1st, none of us are ‘experts’..we just try to provide help or guidance where possible, but you asked for help and it was provided but you did not like it or found the persons providing the help to be unacceptable according to someone else’s saying. By the way, Ubbe has always tried to help and whether you agree or not has pointed out extremely helpful things to me and others and it makes no difference what country he is in. Yes, you will get conflicting opinions…IT’S A HOBBY! Please do not take things so seriously or personally. Relax and enjoy.

As far as your question, when you apply the various filters does it actual improve hearing the voice? If the filters do not seem to stick, atmospheric conditions on a day to day basis can affect this. I have that problem here all the time. I found that wide invert is usually best but some days normal is but I now leave the filters alone since I always receive ok voice. Not a perfect world. If you are actually receiving what you want to receive relatively consistently, then there is no problem and you can just experiment for fun.

 

[chad_96]

SDS scanners use a 75 cent receiver chip (that replace components used in other scanner of perhaps 10 dollars) that are intended to be used in satellite receivers and TV receivers are not all all suitable for wide dynamic signal levels that exist for police scanners. The receiver has a huge amount of false frequencies that mix inside the receiver so that one received frequency will pop up at hundred other frequencies. SDS100.mp4

During beta testing it was apparent that the receiver was not good enough but Uniden had already decided to use this cost saving solution, that also makes it possible to properly receive simulcast systems. They had made less profit from all the recalls and free service of bad displays and clock circuits in the prior 436/536 scanners and wanted a boost in profit. To solve this reception problem without replacing hardware with a more costly one they opted to use a technique that are used in HAM radios called IF shift.

One filter for the IF frequency are 10MHz wide, narrower ones are much better but also more expensive, and the received signal are at most 0.025MHz wide. That wide filter are no issue for "normal" scanners but the SDS receiver are so poor that it becomes a big issue if you have interferencies.

Those filter settings are always using the same 10Mhz filter and in its Off setting the received signal are in the middle of that 10MHz window, receiving all kinds of other radio signals within a 10MHz spectrum around the received frequency. When you select different filters it only change the oscillators in the receiver so that the 0.025MHz received signal moves from the center of the filter and more to the edges of it.

The theory are that if you receive 850MHz in the middle of the filter then another transmitter at 855MHz will get thru the filter and create interference in the receiver as the filter are +/-5MHz wide, but if your received signal are changed so it will be at the edge of the filter, 1MHz from the high frequency edge and 9MHz from its lower edge, then that 855MHz at +5MHz will be outside of the filters range and will not slip thru it. The problem then are that you might have interfering signals 9Mhz lower in frequency that then instead will go thru the filter and create havoc in the receiver.

It all depends of your unique local RF situation. Some people say that SDS scanner are bad analog scanners but it is the exact same hardware used in digital, but in digital you don't notice the problem as much as you either hear the digital conversation or you don't and you are not really listening to interferences as you are doing in analog mode where you are hearing the "raw" signal and not a decoded data signal.

The recommendation from Mr. Opitz to choose another scanner model came from his knowledge of the flawed received used that would not perform as well as "normal" scanners but are the only choice if you want to receive simulcast systems.

SDS scanners has the same functions and features as the 436/536 but with the added simulcast capacity, so if you don't need that then a 436/536 scanner would be more suitable. Uniden left out all technical specs in their user manual for SDS scanners, as that might be used against them in US where people sue companies but in the EU the manual have all specifications of the receiver.

/Ubbe

Thanks Ubbe. I just simply found it crazy to think another model scanner would be better, whe. Many claimed the filter off position was the same as using another uniden scanner, as these things are not cheap and should work much better for the consumer at the prices.

I appreciate you and your help and clarification on all of this. You made it very more understanding. I was just busting your balls a bit.

I think my only real question to everyone including you, after that well put together information is if I were to again get an antenna, a discone type like the tram 1400 and put it up in my attic as many have suggested to me previously on another thread, could that also help with this issue of constantly flipping filters by getting a higher antenna, as outside just isnt going to work? Or would that not be connected in any way somehow?

 

[chad_96]

Pardon my intruding on a situation where people are trying to help you…1st, none of us are ‘experts’..we just try to provide help or guidance where possible, but you asked for help and it was provided but you did not like it or found the persons providing the help to be unacceptable according to someone else’s saying. By the way, Ubbe has always tried to help and whether you agree or not has pointed out extremely helpful things to me and others and it makes no difference what country he is in. Yes, you will get conflicting opinions…IT’S A HOBBY! Please do not take things so seriously or personally. Relax and enjoy.

As far as your question, when you apply the various filters does it actual improve hearing the voice? If the filters do not seem to stick, atmospheric conditions on a day to day basis can affect this. I have that problem here all the time. I found that wide invert is usually best but some days normal is but I now leave the filters alone since I always receive ok voice. Not a perfect world. If you are actually receiving what you want to receive relatively consistently, then there is no problem and you can just experiment for fun.

Yeah I apologize, I found the statement odd and was busting his balls a bit. I don't give a crap who likes who. I get you..

So one common thing about the filters is, and not all days, but it seems over the last 4 days I spend more time on the invert a d wide invert filters, back and forth. Once I get one to stick for how ever much time I get I would say 95% of transmissions without error. That is until it starts to have issues with that filter and then it more and more garbled.

I'm just left to wonder as a last effort before I take this thing outside and fill it full on tanerite and make it a explosive target, I was suggest to try a discone antenna in my attic, like the tram 1410. I'm just curious if that would help out the reception/signal enough to not have to flip the filters so much or if it wouldn't help the situation at all.. I'm not sure and on my last nerve with the thing

 

[tvengr]

I've had a lot of good results using the wide invert filter.

 

[chad_96]

I've had a lot of good results using the wide invert filter.

Yeah it seems I tend to use the invert and wide invert a lot more than others. Again, having to switch back and forth. And sometimes neither of the two.

 

[a727469]

Yeah I apologize, I found the statement odd and was busting his balls a bit. I don't give a crap who likes who. I get you..

So one common thing about the filters is, and not all days, but it seems over the last 4 days I spend more time on the invert a d wide invert filters, back and forth. Once I get one to stick for how ever much time I get I would say 95% of transmissions without error. That is until it starts to have issues with that filter and then it more and more garbled.

I'm just left to wonder as a last effort before I take this thing outside and fill it full on tanerite and make it a explosive target, I was suggest to try a discone antenna in my attic, like the tram 1410. I'm just curious if that would help out the reception/signal enough to not have to flip the filters so much or if it wouldn't help the situation at all.. I'm not sure and on my last nerve with the thing

Please send it to me before you explode it😢. Anyway most times an outside, high antenna will do wonders. Mine is only in my garage roof inside and it makes all the difference. My antenna is actually cut for vhf high since that is the majority of my p25 and analog listening but a discone is ok, but a compromise. The attic should be ok as long as no large metal objects in the way. I am not familiar with your system, but if 800mhz then one for that range would be best with some type of preamp if possible. Best antenna is always one cut specifically for the frequency being monitored or transmitted and especially if weak signals. Also, you must be able to move the antenna around in the attic to test since a few feet/inches can make a difference. Whether this would help with the filter consistency, I do not know, but in theory, it should.

 

[chad_96]

Please send it to me before you explode it😢. Anyway most times an outside, high antenna will do wonders. Mine is only in my garage roof inside and it makes all the difference. My antenna is actually cut for vhf high since that is the majority of my p25 and analog listening but a discone is ok, but a compromise. The attic should be ok as long as no large metal objects in the way. I am not familiar with your system, but if 800mhz then one for that range would be best with some type of preamp if possible. Best antenna is always one cut specifically for the frequency being monitored or transmitted and especially if weak signals. Also, you must be able to move the antenna around in the attic to test since a few feet/inches can make a difference. Whether this would help with the filter consistency, I do not know, but in theory, it should.

Thanks for the advice. I am going to see what all options are out there as far as antennas, and hopefully, I will be able to remedy this by that, even if it's still not completely resolved, something has to be able to help in somewhat of a way. I don't think the issue is a defective radio, but
I believe this is a more uncommon issue that needs an approach, experimenting, and an approach to help. I've seen others with this exact same issue, but don't know what environment they are in/around.

Attic area for a discone was suggested to me previously. I hate to throw money at something that isn't a proven improvement, but without logical responses from anyone who's actually dealt with this exact situation and an actual remedy, what's a person left to do. Unfortunately, looking up there, they left the old furnace unit in thr attic. So setting it up on top of that would be the only way. Not sure if that's logical or not setting it up on the old furnace.

It would be much nicer to not have a rental house that I could just do an outside antenna on a mast. Unfortunately, not an option. I've tried a mag mount with the cable ran out the window onto my metal roof. Unfortunately, the cable length restricted how far I could go and was at a lower point. So, that didn't do anything different for the most part, and wasn't in the best area to test, but only place to actually try it out.

Anyways, will do some more researching through the web and see what all I come up with and try on the topic and issue. And I will try not to make a target out of it. But I sure would like to sometimes.

 

[chad_96]

I assume that you are getting better RSSI/D-Errors on the LaJunta (distant) site than on the Fort Lyons (local) site.

The LaJunta tower is higher and has more power than the Fort Lyon tower. This will contribute to better reception from LaJunta even though it is further away.

The Fort Lyon tower is only 30’ high and has ERP of 177W.
The LaJunta antenna is 122’ high and has ERP of 212W. In addition, the LaJunta site is 100’ higher than Fort Lyon - so the antenna is about 190’ higher at LaJunta with 35 W more power (if you believe the license info).

Yes, I get the la junta site much better than the local site.

I also have a very large mesa that runs behind my area that, honestly probably shouldn't allow much of a signal at all from the la junta site since it's quite a distance behind it. But, yes I do get great signal from the La Junta site vs. The local for lyon site.

 

[Ubbe]

Yeah it seems I tend to use the invert and wide invert a lot more than others. Again, having to switch back and forth. And sometimes neither of the two.

Program the system twice, or even several more times, and have different filter settings for each and use their quick keys to easily go from one system to the next that then has a different filter setting. Maybe it will help to detect any pattern in your issues.

Paying $20 for the Waterfall feature could show on the display what actually happens in your radio spectrum. As others have mentioned you could have some other type of issue, maybe the scanner are faulty and needs to be repaired. That's difficult to know but the first amplifier in the scanner are sensitive to static discharge like in a lightning strike, but then it would be a permanently bad reception.

I have mostly -80dBm to -90dBm signals from systems in my scanner but have two frequencies that are blocked from other frequencies and trying different filters and IFX only gets it blocked from some other frequency. So no point for me to use a SDS100 to receive those two frequencies. If those where digital systems it would have been difficult to know what was going on. The waterfall would probably show those kind of issues when an image of another frequency happens to land on the frequency that you want to receive. It's very frustrating using these SDS scanners as they are no better than a $20 SDR dongle in RF performance.

/Ubbe

 

[chad_96]

Program the system twice, or even several more times, and have different filter settings for each and use their quick keys to easily go from one system to the next that then has a different filter setting. Maybe it will help to detect any pattern in your issues.

Paying $20 for the Waterfall feature could show on the display what actually happens in your radio spectrum. As others have mentioned you could have some other type of issue, maybe the scanner are faulty and needs to be repaired. That's difficult to know but the first amplifier in the scanner are sensitive to static discharge like in a lightning strike, but then it would be a permanently bad reception.

I have mostly -80dBm to -90dBm signals from systems in my scanner but have two frequencies that are blocked from other frequencies and trying different filters and IFX only gets it blocked from some other frequency. So no point for me to use a SDS100 to receive those two frequencies. If those where digital systems it would have been difficult to know what was going on. The waterfall would probably show those kind of issues when an image of another frequency happens to land on the frequency that you want to receive. It's very frustrating using these SDS scanners as they are no better than a $20 SDR dongle in RF performance.

/Ubbe

Thanks ubbe, that sounds like a great way to test and move forward. I will give that a try. And thats very understandable. I apologize, I was just trying to give you a hard time. But, I do appreciate all your help.i don't know crap about most of this scanner stuff and frequency and so on. Just been learning as I go. Have got a lot of things handled and learned a lot. Just the filter issue remains a mystery.

Anyways, thanks again ubbe!

 

[sonm10]

I'll throw out my .02¢

You may be too far away. You have told us nothing of your antenna setup. Filters will do nothing if the antenna can't "hear" it. You might try an outdoor antenna. You might also try an low noise amplifier (LNA) to boost the signal.

Also, what is your feed line and are you splitting between multiple receivers?
You won't receive anything if you're use lossy coax or splitting passively.

Put the RSSI field on the screen and see what the signal strength is. If you are below -100 you will need to boost the signal somehow.

 

[trentbob]

OP.. you've got the number of good suggestions here and attention. I looked at the history of your posts and it would seem this is a reoccurring theme, just header is different.

I just wanted to reiterate my opinion and observations, as things have gotten somewhat unnecessarily contentious here I have kind of backed off.

First of all I'm going to repeat again, I don't think you have a filter problem, I don't think the filters are faulty, I have recommended that you put both sites on wide invert, as has been said that is a popular filter for systems. Depending on atmospheric conditions and propagation I occasionally have to switch over to wide normal when I noticed fluctuations in reception due to conditions.

There have been some suggestions made that it seems that you are resistant to or say you have already tried. There is a chance that you're having issues with possibly being out of range, too far away, conditions change throughout the day which might be responsible for the fluctuations that you're seeing in reception that the filters aren't really going to help that much.

Changing the location of the radio in your house, taking it outside, moving the antenna around are also factors that may help.

I understand that you can't have an antenna on your roof but have you thought of getting a floor lamp at Walmart along with a broom handle and mounting an outdoor antenna on the floor lamp with about 10 ft of low loss coax with enough room to move the floor lamp and antenna around near a window, rotating it and changing position to help with reception in case you are close to being out of range?

Just some suggestions.

 

[trentbob]

I'll throw out my .02¢

You may be too far away. You have told us nothing of your antenna setup. Filters will do nothing if the antenna can't "hear" it. You might try an outdoor antenna. You might also try an low noise amplifier (LNA) to boost the signal.

Also, what is your feed line and are you splitting between multiple receivers?
You won't receive anything if you're use lossy coax or splitting passively.

Put the RSSI field on the screen and see what the signal strength is. If you are below -100 you will need to boost the signal somehow.

I did not see your post until after I did mine but I think we're thinking the same.

 

[a727469]

OP.. you've got the number of good suggestions here and attention. I looked at the history of your posts and it would seem this is a reoccurring theme, just header is different.

I just wanted to reiterate my opinion and observations, as things have gotten somewhat unnecessarily contentious here I have kind of backed off.

First of all I'm going to repeat again, I don't think you have a filter problem, I don't think the filters are faulty, I have recommended that you put both sites on wide invert, as has been said that is a popular filter for systems. Depending on atmospheric conditions and propagation I occasionally have to switch over to wide normal when I noticed fluctuations in reception due to conditions.

There have been some suggestions made that it seems that you are resistant to or say you have already tried. There is a chance that you're having issues with possibly being out of range, too far away, conditions change throughout the day which might be responsible for the fluctuations that you're seeing in reception that the filters aren't really going to help that much.

Changing the location of the radio in your house, taking it outside, moving the antenna around are also factors that may help.

I understand that you can't have an antenna on your roof but have you thought of getting a floor lamp at Walmart along with a broom handle and mounting an outdoor antenna on the floor lamp with about 10 ft of low loss coax with enough room to move the floor lamp and antenna around near a window, rotating it and changing position to help with reception in case you are close to being out of range?

Just some suggestions.

I support trentbob’s suggestions especially concerning not being a filter problem. As stated, try working on some antenna options and if not possible, please, please, please take this as a suggestion not a criticism….. Accept your reception issues and take your mind off this because I think this has been very frustrating to you and it is not worth it. Life is too short!😉.

 

[chad_96]

OP.. you've got the number of good suggestions here and attention. I looked at the history of your posts and it would seem this is a reoccurring theme, just header is different.

I just wanted to reiterate my opinion and observations, as things have gotten somewhat unnecessarily contentious here I have kind of backed off.

First of all I'm going to repeat again, I don't think you have a filter problem, I don't think the filters are faulty, I have recommended that you put both sites on wide invert, as has been said that is a popular filter for systems. Depending on atmospheric conditions and propagation I occasionally have to switch over to wide normal when I noticed fluctuations in reception due to conditions.

There have been some suggestions made that it seems that you are resistant to or say you have already tried. There is a chance that you're having issues with possibly being out of range, too far away, conditions change throughout the day which might be responsible for the fluctuations that you're seeing in reception that the filters aren't really going to help that much.

Changing the location of the radio in your house, taking it outside, moving the antenna around are also factors that may help.

I understand that you can't have an antenna on your roof but have you thought of getting a floor lamp at Walmart along with a broom handle and mounting an outdoor antenna on the floor lamp with about 10 ft of low loss coax with enough room to move the floor lamp and antenna around near a window, rotating it and changing position to help with reception in case you are close to being out of range?

Just some suggestions.

A reoccurring theme? You've lost me. I have 2 posts regarding filters not working as they have worked for others. This thread, as well as the same in the colorado group, that seems pretty unused and silent.

I've noted the advice, and can only logically try what I can logically try. Nothing more.

I've gotten great advice. Alot of it. I've also received some very off topic comments

Anyways, thanks

I support trentbob’s suggestions especially concerning not being a filter problem. As stated, try working on some antenna options and if not possible, please, please, please take this as a suggestion not a criticism….. Accept your reception issues and take your mind off this because I think this has been very frustrating to you and it is not worth it. Life is too short!😉.

Most sensible post ive seen yet! Thanks. I actually had someone reach out with a fix for this, and so far so good. Time will tell though.

Thanks!