SDS100/SDS200: What is the difference with all the filters in the sds100 scanner?

[fxdscon]

Ok. Probably best for me to print it out. Write some notes. Seems crazy to me (not you or anybodys fault) that a radio that is so costly doesn’t come in better basic working order and with better instructions included.

Thank you kindly for responding. I’ll comb over this Carefully.

One last question. If I’m back to doing this from the radio, where should I set those filters I changed in Sentinel?

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Download the PDF filter settings sheet in this post:

SDS100/SDS200: - can i add or adjust individual filters for my sds100?

anyone know if theres is a way to adjust individual filters instead of just using global for all? example if im monitoring say tucson pd tucon fire and tucson medical each can have there own custom filter instead of what my global filter is set to?

forums.radioreference.com

 

[trentbob]

Thank you also for your kind response! Illlook at this again later this afternoon!

Trying to keep this in a nutshell, the global filters affect every object in the radio. You use them to sample filters on a particular system or conventional object, on the radio itself, so as to sample real time reception indicators.

When you find a more optimal filter then you return global to its default setting of normal so as not to compromise reception on objects that work well on normal. Refer to other post in this thread and the many other threads on filters for what filters to try and what the real time reception indicators are.

Assuming you might be on the go when you're making your sampling because of a new location or RF environment, you use the menu and the keyboard to drill down to site options on a system or department options on a conventional object and change the filter there.

As soon as possible you hook up to Sentinel and transfer the data from your card into your profile first thing so as to keep any changes you made directly on the radio ti your profile.

It's all here in this thread and many others. You want a consistent, uniform, predictable system to use and not just sample willy-nilly.

 

[trentbob]

Oh and as far as your question of why it is not in the manual? When the SDS radios first came there were problems with reception on conventional objects and there was broken, missing and clipped transmissions on some systems.

The Uniden product manager at that time introduced the filters in two steps in firmware updates in an attempt to correct these problem and it worked, unfortunately that gentleman was very ill and passed and was never able to modify the manual to indicate the proper use of filters, he put information in the firmware update notes.

 

[GROL]

If NORMAL is a High Pass filter, what exactly is an inverted HPF. I have never encountered that terminology with RF or IF filters before.

 

[trentbob]

I've never gotten into exactly how the filters work and UPMan, the old Uniden product manager always said that he would not reveal how the sausage was made.

There is a member Ubbi who does understand these filters very well so look for his posts in the various filter threads. I just use the ones that work the best but don't know why exactly they do LOL.

 

[GROL]

I've never gotten into exactly how the filters work and UPMan, the old Uniden product manager always said that he would not reveal how the sausage was made.

There is a member Ubbi who does understand these filters very well so look for his posts in the various filter threads. I just use the ones that work the best but don't know why exactly they do LOL.

I was hoping to understand what they actually do, but that is apparently not an option. I did look around and search some, but haven't yet come across anything Ubbe may have posted about it.

I was working on improving a local simulcast system, which was already working pretty well with NORMAL. Just some occasional blips in decoding that didn't much affect readability of the audio. Error rates usually not above 10 and often zero. Using Wide Inverted, it improved the error rates to 0-1 most of the time. I was watching Noise readings, but they are all over the place (low hundreds to low thousands) on this simulcast system, which leads me to believe it is due to it being simulcast with 4 repeaters sites all in range. Filters and IFX made no detectable improvement in the noise level, although Wide Inverted improved error rate. Sitting on a non-simulcast site in another system close by, the error rates are zero and noise in the low hundreds.

 

[freqseeker]

I converted Ubbes description to a PDF. Thanks Ubbe for the explanation.

 

[GROL]

Ubbe explains in Post #5 from below thread.. Names of filters are definitely misleading.

SDS100/SDS200: - The Art of Filtering

Based on what I've read in the so-called "Easier to Read" guide and owner's manual, the descriptive part of using filters on this model are rather sketchy. I read where the filters were added to a firmware update; however, the application of such is rather vague to say the least. If anyone...

forums.radioreference.com

 

[GROL]

I converted Ubbes description to a PDF. Thanks Ubbe for the explanation.

Also helpful. A bit better explanation I hadn't yet found. Making a lot more sense now, but filter names are really bad.

 

[GROL]

I converted Ubbes description to a PDF. Thanks Ubbe for the explanation.

If I understand Ubbe's description, then these images represent the filters

 

[jgorman21]

I wanted to take a minute to thank everyone on this thread for responding to my questions about the SDS 100 and filters. I did actually print several of the posts, pictures etc. I spent some time going over them and made a bunch of the suggested “tweaks” and voila! The radio is no longer deaf! I also noted what I changed so I can continue to do more adjustments, but what a difference. Especially in air band and on conventional VHF and UHF! I had one question to “Wereinshades” - well a comment and a question. Your tip about modulation from auto to FM was brilliant. But arent most of these now NFM? Not that I’m complaining by any means - it works! Just a question!

Thank you all again! Your patience and assistance is greatly appreciated.

 

[werinshades]

I wanted to take a minute to thank everyone on this thread for responding to my questions about the SDS 100 and filters. I did actually print several of the posts, pictures etc. I spent some time going over them and made a bunch of the suggested “tweaks” and voila! The radio is no longer deaf! I also noted what I changed so I can continue to do more adjustments, but what a difference. Especially in air band and on conventional VHF and UHF! I had one question to “Wereinshades” - well a comment and a question. Your tip about modulation from auto to FM was brilliant. But arent most of these now NFM? Not that I’m complaining by any means - it works! Just a question!

Thank you all again! Your patience and assistance is greatly appreciated.

That's good to hear, but yes I believe the FCC mandated everyone has to be narrow banded some years ago. While I can't explain the technical side of it, the scanner has always worked best this way on analog transmissions.

 

[jgorman21]

That's good to hear, but yes I believe the FCC mandated everyone has to be narrow banded some years ago. While I can't explain the technical side of it, the scanner has always worked best this way on analog transmissions.

Without question it works! Thanks again. And to Ubbe, Trentbob, Grol, freqseeker, and others!

 

[Omega-TI]

I converted Ubbes description to a PDF. Thanks Ubbe for the explanation.

The PDF was a great idea!

If I understand Ubbe's description, then these images represent the filters

I took your graphics @GROL and combined them with the @freqseeker PDF. At my age having a paper to refer too makes a lot of difference.

 

[GROL]

The PDF was a great idea!

I took your graphics @GROL and combined them with the @freqseeker PDF. At my age having a paper to refer too makes a lot of difference.

Thanks. Nice to have everything in one place for reference. Ubbe's description was a big help. I thought it would be easier to understand with a visual of it.

 

[Omega-TI]

Thanks. Nice to have everything in one place for reference. Ubbe's description was a big help. I thought it would be easier to understand with a visual of it.

It is, especially for newbies. Being home with COVID I have some time to play with my radio now, but feel like something that just crawled out from under a rock, so I'm taking it in a little at a time.

 

[Omega-TI]

I got to thinking (I know bad idea), it would be kind of nice to have some user generated instruction sheets (PDF's) for some things that the manual is not quite clear on, or things that have been big hurdles for people to grasp. I'm going to be home for the next few days and would gladly take assorted graphics and text and combine them all into individual instruction sheets/tutorials.

 

[Ubbe]

That's good to hear, but yes I believe the FCC mandated everyone has to be narrow banded some years ago. While I can't explain the technical side of it, the scanner has always worked best this way on analog transmissions.

It's related to how the squelch works in SDS scanners. In a "normal" scanner you can monitor a signal and can tune the scanner 3.125Khz to the side of the frequency, perhaps even 5Khz, and the squelch doesn't close. But on a SDS it closes as soon as you go off frequency by 2KHz. You will notice this much easier using a signal generator. Changing from NFM to FM will widen the frequency range before the squelch closes.

There's lots of internal interferencies in SDS scanners that will be masked off when the squelch are much more sensitive and "narrow" but it will also have more difficulties to open and will appear sluggish. The NFM mode in SDS are very narrow and close the squelch if you modulate wide as in FM mode, nothing that happens with a "normal" scanner.

The squelch are probably designed this way as it otherwise would constantly open up on a lot of interferencies and "birdies".

/Ubbe

 

[jgorman21]

I got to thinking (I know bad idea), it would be kind of nice to have some user generated instruction sheets (PDF's) for some things that the manual is not quite clear on, or things that have been big hurdles for people to grasp. I'm going to be home for the next few days and would gladly take assorted graphics and text and combine them all into individual instruction sheets/tutorials.

That’s a great idea. In the beginning for me the “Mark’s Scanners” pages I was pointed to from threads on RR were better than the original manual. Omega’s idea could take all of the “best of” explanations from users here and put them in an “SDS For Dummies” type of thing?

To summarize (for me), as I begin to understand things (somewhat) better ultimately the sharing of knowledge aka “Elmering” is what it’s all about!

 

[werinshades]

It's related to how the squelch works in SDS scanners. In a "normal" scanner you can monitor a signal and can tune the scanner 3.125Khz to the side of the frequency, perhaps even 5Khz, and the squelch doesn't close. But on a SDS it closes as soon as you go off frequency by 2KHz. You will notice this much easier using a signal generator. Changing from NFM to FM will widen the frequency range before the squelch closes.

There's lots of internal interferencies in SDS scanners that will be masked off when the squelch are much more sensitive and "narrow" but it will also have more difficulties to open and will appear sluggish. The NFM mode in SDS are very narrow and close the squelch if you modulate wide as in FM mode, nothing that happens with a "normal" scanner.

The squelch are probably designed this way as it otherwise would constantly open up on a lot of interferencies and "birdies".

/Ubbe

Based on this information, it should be suggested for those experiencing issues with analog to change the Modulation to FM, utilize the filters and adjust the Volume Offset to +2 or +3 to compensate for the audio drop you'll experience by modifying the Modulation

What say you @JoeBearcat ?