SDS100/SDS200: Is the SDS100 deaf on the air band?

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beaterbox

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I know the SDS100 covers the air band, but when I put it side by side with my BC125AT, using the same antennas (Diamond RH789) on both, the SDS100 only picks up about 1 out of 10 transmissions that the BC125AT receives. Both radios have the same single airport frequencies programmed. Is this typical with the SDS100 or possibly an issue with the SDS100?

Thanks
 

chmsant

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More likely an antenna problem than a scanner problem. Maybe worth getting a dedicated aircraft band antenna and re-doing your test there. These super broadband antennas aren't necessarily the greatest.
 

Whiskey3JMC

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Lacking in sensitivity? Yes. Deaf? No. I don't listen to a whole lot of analog with my SDS, I have other receivers for that. Out of them all I'd say my Icom IC-R20 is the best on air band. I have yet to compare it with a 125AT though being about 30 miles from an international airport (Too far out to hear tower)
 

trentbob

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My STS radios in my particular area were poor on aircraft band, filters didn't make a difference but function 7 IXF made all the difference, I listen to several Hilo unicorn frequencies everyday and the SDS beats all my other radios. Just shows to go you LOL, it's definitely RF environment.
 

Markb

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Keep in mind that the SDS series was primarily designed to overcome LSM issues and was marketed as such. The end result seems to be that it performs better on these systems than previous models and reception on other bands and modes were more of an afterthought. Hopefully Uniden will start to work on firmware updates that can help with some of these issues.
 

Ubbe

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Hopefully Uniden will start to work on firmware updates that can help with some of these issues.
It's a hardware problem. It would take a better quality receiver chip and several more bandpass filters than what currently are in the scanner to make it perform better. In most cases the receiver are adequate when fiddling with filters and IFX but in demanding RF enviroments it can be hopeless.

But users that own a 125AT often says it has the edge on most other scanners when it comes to airband monitoring, so it will probably always be better in the airband.

/Ubbe
 

trentbob

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I just realized I wrote IXF when I meant IFX. Anyway function 7 made a night and day difference on the air bands. If it means anything it also improved the weather bands.

In my particular location, I am starting to see a pattern with the filters, most of the time VHF- high is greatly improved when wide normal is added to Department options of various VHF groups, especially the Marine band... UHF repeaters do best on the default normal, and all of my tdma Phase ll simulcast systems definitely work better on wide invert applied to the one or two sites I use. No missed or clipped transmissions. Global of course stays at normal for everything else.

That's in my environment, I've noticed that when the filters are sampled in real time using all the right indicators reception is remarkably good on both SDS radios. I guess I'm just in a good spot.
 

beaterbox

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Good information everyone, thank you! I don't believe it's my environment as the scanners are in the same room (even close to each other), using the same antenna. I've even switched the antennas between the two. The BC125AT has the better receiver on the air band hands down. I'll see about playing around with the IFX setting. I simply think the conventional scanner beats out the whiz band digital scanner when it comes to that band.
 

mass-man

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My STS radios in my particular area were poor on aircraft band, filters didn't make a difference but function 7 IXF made all the difference, I listen to several Hilo unicorn frequencies everyday and the SDS beats all my other radios. Just shows to go you LOL, it's definitely RF environment.
Do you get signal reports of rainbows, shooting stars and glitter on the unicorn frequency?😜
GAWD I hate auto fill.....
 

trentbob

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Yep I try to proofread to see what the spell check has in mind for me but I was in a hurry lol. Oh well. :p
 

kc5igh

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Would someone please tell me what "function 7 IXF" is all about?

Thanks!

-Johnnie (KC5IGH)

Ooops! I think "function 7 IXF" is the command that changes the internal frequency setting.

Sorry for the false alarm . . .

-Johnnie (KC5IGH)
 

R0am3r

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In my experience, the SDS radios work quite well on the airband and are hardly deaf. I have a BCT15X and SDS200 and find the SDS is as good (or better) as the analog BCT15X while monitoring the airband. I have tested these radios on the airband using same antenna (MP 08-ANT-0860), LMR400 coaxial cable, and the Electroline distribution amp, and have found examples where my SDS will sometimes pick up signals while the BCT15X remained silent. This isn't a scanning issue, because I tested using a single frequencies from Boston Center and found no case where the BCT15X outperformed the SDS. I will gladly throw my SDS100 on-line using the same antenna if folks believe there is a big difference between the SDS models. Personally, I believe my SDS radios perform exactly the same.
 

Ubbe

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I will gladly throw my SDS100 on-line using the same antenna if folks believe there is a big difference between the SDS models.
Not between models, it's a difference depending of users local RF situation. You can probably be sure of that a BCT15x behaves the same in most any enviroment but a SDS scanner are heavily dependent of how the RF spectrum looks like in each users unique situation.

/Ubbe
 

N8LHG

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Good information everyone, thank you! I don't believe it's my environment as the scanners are in the same room (even close to each other), using the same antenna. I've even switched the antennas between the two. The BC125AT has the better receiver on the air band hands down. I'll see about playing around with the IFX setting. I simply think the conventional scanner beats out the whiz band digital scanner when it comes to that band.
I'm going to toss my two cents in here. In my situation, same antenna, my sds200 is slightly more deaf than my Radio Shack pro 2004 on/in the aircraft band (120MHz AM). I base that on the apparent perceived signal strength, or ability to hear the "tower" signal between the two rigs. I hear the tower transmissions "louder" on the legacy radio shack rig than I do on my sds200. This is one of the reasons I wanted to find the sds200 sensitivity/selectivity specs. Seems my ancient radio shack receiver hears better on that band/mode.
 

richard4537312

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Take a look at some of the many posts in the tech support forum about the infamous "cold solder joint" problem. Loss of aircraft band reception, along with all other VHF reception, was the leading symptom of the problem with my SDS100. Never fear, Uniden fixed it, and now my aircraft band reception is better than any of my other scanners.
 
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