SDS100: What is the difference with all the filters in the sds100 scanner?

KEVINTAAFFE

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hi everybody, first post in this support group. can anybody tell me the difference with all the different filters ,and what each one does so i know what to use and not to use. i live in volusia county florida, port orange to be exact,and need to know if i need to use any filters ,or if there are other scanner people in my county that can help me pull in a lot of systems. Thank You. KEVINTAAFFE:)
 

nessnet

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There is so much info on this here.
May I suggest you do a bit of browsing/searching on this (here).

Not to be rude, but this question literally comes up weekly - ever since the filter firmware was first introduced.
So, there are MANY posts to read for you.

But, basically the bottom line is this. Filters are LOCATION based - it all depends on YOUR specific RF environment. What works for someone in one place, may be completely different at another. You need to just experiment. The best procedure to do this has been posted here.
 

fxdscon

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As mentioned, there are many posts on that subject, and the actual effects of the filters are extremely location/situation dependent.

General setting parameters are listed here:

 

trentbob

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If I could suggest that you look at a recent thread called b c d 436 versus sds100 missed Transmissions from last week in the Uniden Tech forum. I put in a detailed tutorial on how to adjust the filters. It helped the poster... Enjoy.
 

ka3jjz

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We also have this from our FAQ - I'll see if I can find trentbob's thread and add it



It's really deplorable that Uniden can't - or won't - develop detailed explanations on things like this, so we're left to figure these things out ourselves.

Mike
 

MStep

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We also have this from our FAQ - I'll see if I can find trentbob's thread and add it



It's really deplorable that Uniden can't - or won't - develop detailed explanations on things like this, so we're left to figure these things out ourselves.

Mike
A few folks on here posted some fairly good explanations of their experiences with the different filters under various conditions. I don't believe that anyone at Uniden actually understands the true nature or intent of each filter. The architect of the SDS series, as most of you know, is deceased.

So I will do them a favor and write the paragraph for them that should have been in the instruction manual:

First, the English version:

"We have developed a set of filters to help assist with reception of various systems under a number of different conditions. Please feel free to experiment with each filter to see what is most effective under your own operating conditions."

Now, the "Engrish" version that we are accustomed to in many manuals that accompany Asian products:. Google it if you don't know that word:

"Filter set available for use by consumer help improve reception of signal under adverse condition. Different filter effect performance depend on consumer location and system for be monitored."

No offense to our Asian friends. Too irresistible.
 

trentbob

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It was quite a long while ago but somewhere I remember Paul saying, regarding the filters, he wasn't going to give away what is in the sausage. LOL.
 

MStep

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hi everybody, first post in this support group. can anybody tell me the difference with all the different filters ,and what each one does so i know what to use and not to use. i live in volusia county florida, port orange to be exact,and need to know if i need to use any filters ,or if there are other scanner people in my county that can help me pull in a lot of systems. Thank You. KEVINTAAFFE:)
You're definitely going to read A LOT of information in these threads about the "filters" and their various uses. If you are a new to the SDS series, there are some many other great things to learn about the radio that filters would be at the bottom of my list UNLESS you are having trouble with specific system at a specific location.

Here in the New York City area, even with bombardment of thousands of competing signals across the entire radio spectrum covered by the SDS receivers, I have found that for the most part, the time exerted on finding the "right filter" for the "right system" is usually more trouble than it's worth in terms of the actual improvements observed on any particular system.

Many of my friends also have SDS radios, and have asked about the use of particular filters. My advice to them is to save filter experimentation more as a "rainy day" project than something you need to do right away to get enjoyment out of your radio. The way that it is currently set up is not conducive to quickly hopping between filters to observe results.
 
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MStep

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It's really deplorable that Uniden can't - or won't - develop detailed explanations on things like this, so we're left to figure these things out ourselves.

Mike
I agree in theory, but not in practice. The instruction manuals included with the SDS series are woefully inadequate for those seeking highly technical details about many of the features and nuances of the operation of the receiver. You are mostly given a cursory overview to get you started. Can you imagine what life is like for purchasers of the SDS radios who do not have access to these forums?

A more complete "technical" manual of the SDS series would probably end up being a 400 or 500 page document. For those here old enough to go back to the early days of the personal computer (I'm thinking specifically about my Radio Shack Model II), where the hardware manual was 300+ pages in an 8 1/2 x 11 loose-leaf binder and each piece of software came with 300 pages of it's own operating instructions. Of course, I am talking pre-Internet days.

My best guess is that Uniden has neither the time or manpower to dedicate to "publishing"---- they're having their hands full with producing and repairing. If this were "military grade" equipment, you can be sure it would include thousands of pages of manuals, only to be read as a last resort to track down a problem.

I know you were addressing the issues involving the filters--- see trentbob's message just above this one-- he did a really good write-up. Radio Reference is the best place to get the kind of information that Uniden apparently does not have the resources to provide.
 
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n1chu

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We also have this from our FAQ - I'll see if I can find trentbob's thread and add it



It's really deplorable that Uniden can't - or won't - develop detailed explanations on things like this, so we're left to figure these things out ourselves.

Mike
It is my understanding the filter settings were initially bench test tools, available only within the company. But Uniden made them available to all after there were concerns over such complaints as “lost signals” or “scanner hears only one side of the conversation”. Maybe they help, maybe they don’t. Personally, they don’t do anything for me. But that may just be my location. My impression is there are not many who do see improvement when using filter settings… but I could be wrong on that point, I stopped following the hype over the filtering after the complaints slowed. I guess I figured the filters were making a difference but I know of no one around me in Ct. who first has suspected there was a reception problem and second, used filters to correct it. There was probably a touch of paranoia going around when we learned Uniden had agreed with some of the complaints and released the test bench settings as “Filter Settings” in an effort to “fix” the problem and we all started checking for something that was most likely nothing. In my final analysis, I’ve come to believe I’ve got to stop trying to fix things that aren’t broken!
 

Ubbe

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The filter settings are doing IF shift. In most amateur radio receivers you have IF shift that can be adjusted continously from zero to max. Sometimes you have two IF shift on two different IF frequencies like in the Icom R75. Uniden uses 4 fixed settings, Normal / Invert / Wide Normal / Wide Invert and no IF shift in Off. They have two 10MHz wide filters that you can switch between with IFX that will alter the IF frequency between something like 250MHz and 350MHz.

If you are not a radio amateur then you can get a pretty good explanation if you google IF shift.

/Ubbe
 

trentbob

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Filters are definitely for troubleshooting. It is not necessary to apply filters to every object.

Some believe that the sds100 was introduced a little bit early secondary to a vendor releasing information on its existence and Whistler making the announcement that they were making a simulcast capable radio which of course we know they never did.

There were problems when the radio first came out. Uniden got out in front of the short battery life right away. They offered a free larger battery to every existing owner that had a small battery. They produced the larger battery door creating the big butt version.

Another issue was clipped, missed transmissions or skipped transmissions on Phase ll simulcast systems. My hometown system had that issue, I stopped using the SDS 100 and put it in a drawer and went back to my Mot gear hoping that a solution would be found as Paul was putting out new firmware regularly. The radio was a work in progress.

The first set of filters offered in a firmware update where normal which is default, invert and Auto. It was quickly discovered that Auto slowed scanning way down as it sampled each filter. There was an uproar for about 3 or 4 days that an option should be added to have no filter at all and it was. The second set of filters came out which were wide normal, wide invert and Wide Auto.

Global filters are used just to sample what filter is best and it's adjusted on the radio for real time observation of results. When Improvement is found Global is put back on default or normal as Global affects every object in the radio and you don't want to compromise reception on most objects normal works fine on. You then drill down to site options and apply the best filter from your sampling to each site, hopefully you only use one or two sites. I have seen cases where invert was better on one site of a system and wide invert was better on another. I was amazed that invert fixed the problem with my system, no more clipped transmissions or missed or skipped transmissions. When wide invert came out it got even better and reception was improved.

Applying filters to Conventional objects is trickier because you have to wait for a transmission to assess RSSI and noise levels, of course error rates do not apply as an indicator. Some claim that RSSI should not be used and just noise level, I use both. Also you cannot apply a filter to a single Channel. Once you sample filters on Global and find an improvement on a conventional object and you return Global to normal, you have to go to Department options that the frequency is under and change the filter there which will affect all of the frequencies in that department, not usually a problem the way conventional frequencies can be grouped.

It does take effort and time but you really can improve the performance of the radio especially with VHF, UHF and Aviation that we hear complaints about.

If you do it right and take the time it will improve overall performance of the radio. It's a good idea to add the filter indicator to your display. Don't forget, after you make changes on the radio itself using real-time results you must go to Sentinel and first thing you do is transfer the data from your card to your profile so as to permanently keep any changes you made on the radio. My explanation in the thread above is more detailed and step by step.

As far as the technicalities and how filters work, I personally believe in the kiss principal.

Also don't forget to try function 7, IFX makes a difference in some cases... What is IFX? Let's let the man himself tell you, RIP Paul.

PSX_20210629_121948.jpg
 

werinshades

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Start off with Filters Off...if you notice signal degradation, first try adjusting it by site/department. If that seems to resolve the issue, then read it back to Sentinel from the scanner. If you notice most of your systems are sounding the same, adjust the Global Filter to whatever works best.

Remember...whatever you do you won't damage the scanner. It's a trial and error and requires some time to be dedicated to the process.
 

Ubbe

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There's no doubt that the SDS100 where rushed as the big battery where an afterthought and the filters also where an afterthought that where available first after firmware upgrades. The beta testers where not experienced enough or not knowledgable enough to catch the problem with using a sat dish receiver chip that are used in some $10 SDR dongle receivers. Uniden probably didn't inform about the receiver chips performance that the RF AGC reacts to signals 7MHz away from the monitored frequency and the interferencies can occure from signals 5MHz away and 10 MHz when Normal or Invert filter settings are used.

The filters settings are ment to block interfering signals, that will be received and increase the RSSI level. So aim for lowest RSSI level, most negative, and lowest Noise level in analog mode and lowest bit error in digital mode.

It's too bad that there isn't an easier method to test the filters to find the correct one and of course it should be available to individual frequencies and not only a whole department or site. But UPMan where taken away from us much to early and there was no time left to finish the project.

/Ubbe
 

werinshades

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The beta testers where not experienced enough or not knowledgable enough to catch the problem with using a sat dish receiver chip that are used in some $10 SDR dongle receivers.
/Ubbe
Your basing this information on what exactly? Do you know any beta testers? The ones I'm aware of had plenty of experience across the board and are regular "knowledgeable" contributors throughout these forums. I'm not a beta tester either.
 

MStep

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(Clipped for brevity.....)

It's too bad that there isn't an easier method to test the filters to find the correct one and of course it should be available to individual frequencies and not only a whole department or site. But UPMan where taken away from us much to early and there was no time left to finish the project.

/Ubbe
I made the suggestion several months ago that there should be an easy way to just flip through each filter individually while monitoring a system rather then going through the menu system. My recollection is that he said that he would add it to "the list".
 
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