SDS100/200 filter settings

n1chu

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What would be the best choice between “Global”, “Normal”, or “Off” if I don’t care to use any filter setting? I am guessing “Global” seems to be the default setting as all my trunked systems are set to it. I’d like to confirm I have no need for filters and then explore any advantages I may gain.
 

trentbob

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What would be the best choice between “Global”, “Normal”, or “Off” if I don’t care to use any filter setting? I am guessing “Global” seems to be the default setting as all my trunked systems are set to it. I’d like to confirm I have no need for filters and then explore any advantages I may gain.
Okay here is your answer. If you choose not to have any filter on any object on your radio and you have never gone in to a site of a system and adjusted the filter there or you have never gone to Department options and changed the filter on a conventional object then every single object by default on your radio is normal filter now because Global filter is set to normal. If you go to settings and set Global filter to off you will turn off every filter on every object on the radio. If you have going into different sites of different systems or Department options of conventional frequencies you will need to set them back to Global and they will also be off after you set Global filter to off.

If you want to experiment with filters that's what Global filters are for and only for. It allows you to listen to a system or conventional frequency real-time on the radio observing noise level and RSSI and Sample different filters. You already know what normal does so you try wide normal, then you try invert, then you try wide invert. Stay away from the auto filters as they sample every object with every filter and slow scanning way down. After you find the best RSSI and noise level you then return Global to normal and then go into the site or sites of the system you found Improvement on and apply the filter to the site or sites that was the best results on your Global sampling. For conventional objects you need to go to the department options that that conventional frequency is on and apply the best filter that gave you the best results. It will affect every object in that department which often works out because the same filter will help all of the conventional frequencies in that grouping. It's important that you return Global back to normal because you might compromise performance on other objects who do well on default or normal.

Make sure that you put the filter indicator on your display it will help and use a pen and pencil and write down RSSI and noise level results when sampling different Global filters on a particular system or conventional frequency. This is the best way to do it. When you hook up to the computer again make sure to transfer the card to your profile first thing so all the changes you made real time on the radio are recorded. Hope that helps let me know if you have any questions... Bob.
 

n1chu

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Thanks Bob. I’ll try experimenting with the SDS200 in the house. I’ve hesitated trying filters in my truck however... I figure if I did identify a need for and incorporated a particular filter, it would probably apply to the spot I happen to occupy while trying different filters, and change as I drove down the road? Your take on this?
 

trentbob

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That is an excellent question and knowing what I know from what I have learned about filters theoretically RF conditions could change while mobile.

What I learned was what works for me doesn't necessarily mean it works for you. Everybody's environment is different. There are those who get best results with no filter at all. My Aviation reception is nil unless I put ifx on the every Aviation frequency. That may not be the case for everyone.

So to answer your question specifically what I have learned speaking with others in my County with regards to our tdma Phase 2 system is that it isn't just your RF environment it's also the system that reacts to different filters. To clarify, no matter where you are in my County mobile or otherwise wide invert is the best filter for the system. Theoretically it doesn't make sense because it should be in accordance to where you sit but apparently there is some latitude and it's area based rather than the 10 square feet that the radio is in if that makes any sense.

I take my SDS 100 mobile and it seems that all of my filter settings remain optimal as I travel around my area. I know it doesn't make a lot of sense but it seems to prove true for me.

Filters for me have always been something that doesn't need to be applied other than the default normal filter that a system would be on. If there's clipped transmissions or missed transmissions then there's a problem and I need to troubleshoot and experiment and it does solve the problem. I definitely have gotten inprovement on marine frequencies with wide normal and that is consistent area-wide.

What I've learned and the reason I use my system is you have to have some kind of consistency and control over the method you use to apply filters. How many times have we heard oh you just try whatever works willy-nilly. I like to make it more of a scientific definitive way of optimizing performance of the radio. So I would say use the same settings that you use in your shack, in your truck.
ps... that's subject to change of course if you find problems with reception in the truck LOL
 
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trentbob

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Oh and I forgot, when sampling different filters on a system not only do you use real-time results of RSSI and noise level but people also use error rate.
 

MAguln8839

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Is there any way to change to different filters without going through the menu system? Any way to do it on the fly with 1 or 2 key presses?
 

trentbob

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Is there any way to change to different filters without going through the menu system? Any way to do it on the fly with 1 or 2 key presses?
Nope... using Global filters first as a sampler then returning Global to normal which is the default and then drilling down to the site or Department options and applying the filter is the quickest way.
 

trentbob

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Ok.Thanks again. Yours is the first post that made any real sense!
Thank you, I'm glad you like it. The filters were introduced through firmware updates to improve glitches and performance after the radio was introduced. I remember the morning that Paul introduced the first set of filters and I read very carefully his description of their use with the firmware release. It made all the difference in the world on my Phase 2 system which was experiencing clipped transmissions and missed transmissions so I'm a believer and mastered them from that moment on.
 

werinshades

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When I was experimenting with the filter settings, I tweaked them by site/department first before changing the Global settings as it changes everything. After some time and tweaking, I then discovered most systems/departments used a common setting and updated the Global setting. The others had no effect so it made no difference.

Another little trick i've posted across different SDS 100/200 forums is to change the Modulation setting on troublesome analog systems, in addition to above mentioned filter settings. My SDS scanners went from "ho-hum" on analog systems, to working as well as (and in some cases better) than the x36hp scanners that used to occupy the same place and antenna. One additional suggestion is changing the Volume Offset to +2 or +3 as by doing this, the audio has a slight drop out. Others have reported success, some haven't.

I understand many come here looking for a definitive answer on certain features, but the filter settings are one of those that you must be patient and try the different options. As many have said "your results may vary". By trying the suggestions, you will not damage the scanner in any way. You can always return to your profile and put the scanner to it's previous programming. Any successful changes you make manually, be sure to read it back to the scanner and save in Sentinel/ProScan etc.
 

Ubbe

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Oh and I forgot, when sampling different filters on a system not only do you use real-time results of RSSI and noise level but people also use error rate.
Try to avoid using RSSI as a guide as that can be misleading. It senses signal strenght over a huge frequency span and not only from the exact frequency you are monitoring. An interfering signal from another frequency will make the RSSI increase, even 7MHz away. So if anything, you should aim to get the lowest RSSI value, the lowest signal strenght where the interference will be at its minimum, and at the same time keep an eye on the NOISE level that should be the lowest possible when trying filters.

The only indicators you can trust would be the NOISE level for analog and bit ERROR for digital, trying to make them as low as possible. The NOISE level will fluctuate when someone modulates on the carrier so it's a bit difficult to use but try to read the value whenever there's a pause in the conversation. But if a filter change will make a difference then you will probably see that the NOISE level will swing between something like 50-500 for the correct filter and 1000-5000 from the incorrect one when an analog channel are active.

There's an auto setting that lets the scanner select between Normal and Invert and a Wide auto setting that will choose between Wide Normal and Wide Invert. It will toggle between the two filters and tries to see which one that will give the best performance and as that takes some time it will slow down the scan rate.

/Ubbe
 

trentbob

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Try to avoid using RSSI as a guide as that can be misleading. It senses signal strenght over a huge frequency span and not only from the exact frequency you are monitoring. An interfering signal from another frequency will make the RSSI increase, even 7MHz away. So if anything, you should aim to get the lowest RSSI value, the lowest signal strenght where the interference will be at its minimum, and at the same time keep an eye on the NOISE level that should be the lowest possible when trying filters.

The only indicators you can trust would be the NOISE level for analog and bit ERROR for digital, trying to make them as low as possible. The NOISE level will fluctuate when someone modulates on the carrier so it's a bit difficult to use but try to read the value whenever there's a pause in the conversation. But if a filter change will make a difference then you will probably see that the NOISE level will swing between something like 50-500 for the correct filter and 1000-5000 from the incorrect one when an analog channel are active.

There's an auto setting that lets the scanner select between Normal and Invert and a Wide auto setting that will choose between Wide Normal and Wide Invert. It will toggle between the two filters and tries to see which one that will give the best performance and as that takes some time it will slow down the scan rate.

/Ubbe
Well Ubbi, not only do I recommend RSSI, noise and error rate but I recommend your... ear. I have found filters that offer a lower RSSI but don't sound as well as another filter with a higher RSSI which you have already pointed out. As far as Auto filters go... do not use them as a sample in global filters as they do not indicate which filter did the trick. What's the point? I've never tried it but I guess if you're listening to one system or maybe one talk group and you are in a mobile application over a vast area even though there will be a remarkable reduction in scan rate or should I say... Receive rate it would probably find the best filter... Something you could do on your own in a matter of minutes. Just saying:)
 

trentbob

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The auto setting are probably just for mobile use where you cannot focus on complicated scanner settings, or if you plainly do not have the technical skill needed to fiddle with settings and evaluating results.

/Ubbe
I agree with that, the user still has to pick either the pair of normal filters or the pair of invert filters. Also because it samples filters on every object it really does slow scanning down on a radio that already scans slowly.

I just wanted to point out that when you are doing your global filter sampling using real-time results on the radio don't waste your time sampling auto filters as you never know what filter did the trick anyway.

I guess it would be pretty nice if it did record the best filter during a sampling, it would make the process a lot easier. We can add that to the long wish list of improvements we would like to see that will probably never happen lol.
 

Ubbe

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I just wanted to point out that when you are doing your global filter sampling using real-time results on the radio don't waste your time sampling auto filters as you never know what filter did the trick anyway.
Initially the SDS100 did so porly that Uniden (UPMan) needed do something and adding a software function in firmware to add IF shift where the best that could be done without redesigning the hardware. It started with the Normal - Invert setting as a test for those that had problems and later became permanent and then the Wide where added. But the user GUI where a compromise to quickly deliver a solution and if UPMan would have stayed with us would surely have refined it to a more user friendly function, in the similar way that Fn+7 toggles the IFX to directly apply to a frequency. One would think that it would had been easy to display what the auto function where actually using. But Unidens scanner division where more or less paralyzed when UPMan where absent from work and he probably where totally focused on documenting his knowledge to make it possible to forward his legacy to someone else. Someone that still has to pick up the bat and step up to the plate.

SDS scanners are selling like hot cakes so Uniden doesn't need to do any enhacements in the nearest future to keep up their sales. So probably no major updates within the nearest year.

/Ubbe
 

trentbob

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Yes as I had said in Post 9 about Paul introducing the first set of filters and how it made all the difference for my P2 system that had missed and skipped transmissions. Now it is encrypted.

No firmware update since April 15, 2019. Everybody has their own opinion but I personally don't see any improvements coming out or any bugs being attended to in the foreseeable future but that's off topic here and there's plenty of threads out there that address this. Who knows what Uniden plans or what their business model is as encryption spreads faster than the virus. Again, a topic for another thread. (y)
 

garys

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I looked, but couldn't find the document you're referencing. Can you point me in the right direction. I'd like to read what Paul had to say since I don't recall ever seeing it before.

Thank you, I'm glad you like it. The filters were introduced through firmware updates to improve glitches and performance after the radio was introduced. I remember the morning that Paul introduced the first set of filters and I read very carefully his description of their use with the firmware release. It made all the difference in the world on my Phase 2 system which was experiencing clipped transmissions and missed transmissions so I'm a believer and mastered them from that moment on.
 

trentbob

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I looked, but couldn't find the document you're referencing. Can you point me in the right direction. I'd like to read what Paul had to say since I don't recall ever seeing it before.
The first set of filters was normal, invert and Auto and was the beta version but there was no turning the filters off completely, I had to learn it somewhere because nobody else knew anything about the filters except Paul and I had figured it out by that afternoon.PSX_20201109_172111.jpg
Okay it's in Wiki and unfortunately I could not actually put the link to it on my phone but you'll figure it out. But this is firmware notes you're looking for, the actual firmware updates were 1.07.00,.02 and.04... Paul actually explains about the auto filter slow scan problem, he describes how to go into site options and apply a filter for systems and he describes going into Department options to apply a filter to a conventional object so this is where I learned it. The last filter update 1.07.4 is where he added filter off... finally, LOL.
 

fxdscon

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Thanks. I should be able to find it.
Filter settings are available in both Sentinel (in the favorites list editor),

and in the scanner's menu system:

MENU --> SETTINGS --> GLOBAL AUTO FILTER
⦁ Normal (always use High Pass Filter)
⦁ Invert (always use inverted HPF)
⦁ Auto (try HPF then if no signal detected to open squelch, try inverted HPF)
Note: If Auto is selected, conventional scan and search speed will be greatly slowed, as every frequency on which a signal is not detected on first pass will be rescanned using the inverted HPF setting.

MENU --> MANAGE FAVORITES --> REVIEW/EDIT SYSTEM --> EDIT SITE --> SET FILTER (Setting menu for trunked systems)
⦁ Global (use the setting from GLOBAL AUTO FILTER)
⦁ Normal
⦁ Invert
⦁ Auto

MENU --> MANAGE FAVORITES --> REVIEW/EDIT SYSTEM --> EDIT DEPARTMENT --> SET FILTER (Setting menu for conventional systems)
⦁ Global (use the setting from GLOBAL AUTO FILTER)
⦁ Normal
⦁ Invert
⦁ Auto

MENU --> SRCH/CLOCALL OPT --> SET FILTER (Setting menu for Close Call and Search)
⦁ Global (use the setting from GLOBAL AUTO FILTER)
⦁ Normal
⦁ Invert
⦁ Auto
 
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