SDS100/SDS200: SDS100 Airband Performance?

[FoeHammer]

Im trying to understand those that have problems with poor reception on airband , or even other bands ,,If I am understanding right , the chip has an auto gain function ,..which sound like to me that it automatically adjusts the gain or noise floor signal strength in relation to squelch level ? or does it adjust squelch level too ? Anyway the point is maybe performance reports should include weather the location is rural in a low rf environment or in a city ,..So if I live in the middle of a city with tonnes of signals & broadcast stations around ,..it may not work so good , but if im out where not much is going on it will perform better ? Is that why we see such different reports ? Im just trying to understand how it works ,what is causing the issue & if it's firmware fixable or not , the reports from its great to its terrible , are confusing as to why ...

 

[woodpecker]

Im trying to understand those that have problems with poor reception on airband , or even other bands ,,If I am understanding right , the chip has an auto gain function ,..which sound like to me that it automatically adjusts the gain or noise floor signal strength in relation to squelch level ? or does it adjust squelch level too ? Anyway the point is maybe performance reports should include weather the location is rural in a low rf environment or in a city ,..So if I live in the middle of a city with tonnes of signals & broadcast stations around ,..it may not work so good , but if im out where not much is going on it will perform better ? Is that why we see such different reports ? Im just trying to understand how it works ,what is causing the issue & if it's firmware fixable or not , the reports from its great to its terrible , are confusing as to why ...

The 836 tuner has a built in AGC which controls the LNA and I/Q gain stages, you can adjust the IF gain via the VAGC pin which adjusts the VGA gain, these are cheap TV tuner chips which give mediocre RF performance, the performance will be similar to a $10 dongle.

Rafael Micro are known to have poor yields on these cheap tuner chips, this could be one of the reasons for the variation, RF environment will be another, these chips are easily overloaded.

For analog, firmware adjustment will be mostly gain tweaking, too much and it will overload, too little and it will appear deaf, ideally you would have the option of manual gain like a dongle.

I get the impression that most who report it as "great" are bamboozled by the color display and find it works ok listening to LSM, those who know how to test a radio and have something to compare it against notice its weak RF performance.

Uniden publish no RF spec for it, for me that says it all.

 

[KevinC]

Im trying to understand those that have problems with poor reception on airband , or even other bands ,,If I am understanding right , the chip has an auto gain function ,..which sound like to me that it automatically adjusts the gain or noise floor signal strength in relation to squelch level ? or does it adjust squelch level too ? Anyway the point is maybe performance reports should include weather the location is rural in a low rf environment or in a city ,..So if I live in the middle of a city with tonnes of signals & broadcast stations around ,..it may not work so good , but if im out where not much is going on it will perform better ? Is that why we see such different reports ? Im just trying to understand how it works ,what is causing the issue & if it's firmware fixable or not , the reports from its great to its terrible , are confusing as to why ...

Along these lines I equate it to the GRE-based scanners...if you have no FM broadcast near you VHF-Hi works great. If you do have FM broadcast near you it absolutely sucks.

 

[mule1075]

I get the impression that most who report it as "great" are bamboozled by the color display and find it works ok listening to LSM, those who know how to test a radio and have something to compare it against notice its weak RF performance.

Works great for me and I am hardly bamboozled. It does have a minor issue with some adjacent channel interference but I believe it will be worked out. And I do know how to test a radio so no worries about that. Do you own one though I don't remember if you do. If you don't how are you comparing it's supposedly weak RF performance?

 

[werinshades]

I get the impression that most who report it as "great" are bamboozled by the color display and find it works ok listening to LSM, those who know how to test a radio and have something to compare it against notice its weak RF performance.

Not true at all. Having owned a 396T, 396XT, 436hp running the latest firmware which tweaked the analog but was not reported in the release notes, the SDS100 is similar and in some cases better analog reception then all three of my previous handhelds. Living in a high RF/intermod environment called Chicago, I have been all over the area including the suburban areas and hear everything very well. Not some amateur here that's star struck over the bells and whistles. Of course the simulcast issue being resolved is a welcome relief.

 

[nanZor]

For better airband performance, don't overlook the commercial Icom FA-B02AR airband duck. Designed for airband *transceivers* , not only is it resonant, BUT it is also VERY, very narrowband.

I've used them for years on scanners, and even without any detectable desense, the noise floor is lower.

Unlike typical scanner antennas, or those that claim to be airband-resonant, many are still wide-banded more or less.

Not so with the Icom FA-B02AR. FM broadcast reception sucks, And that's a good thing if you can't improve the front-end of the receiver.

You won't find this at your normal scanner / radio outlet. You get them from pilot-shops, or perhaps your nearby FBO shop might have them as replacements since they are popular.

Just know that due to being so narrowbanded, they are easily detuned by being placed close to metallic surfaces, or worn next to your body.

HIGHLY recommended, mostly due to the very narrow tuning. They are bnc connectorized, but the sma-bnc adapter Uniden supplies makes it very easy to get going.