SDS100/SDS200: Military/Civil airband performance?
- Thread starter EAFrizzle
- Start date
Generally speaking, there isn’t enough difference to be concerned about…
With that said, the SDS200 does cover those aviation bands and you are correct when you ask about a receiver that is tuned specifically for the air bands receiving better. But it’s not all that much improvement. The SDS200 is designed to favor the 700/800 MHz bands more than the VHF High and UHF Bands where the aviation frequencies reside. But aircraft have line-of-sight with control towers and other aircraft, which means you also have line-of-sight with the aircraft, so any slight degradation in reception with the SDS200 is minimal. It all depends upon if you are looking to monitor other bands and agencies or just civil and military aviation. Once that question is answered you can start your search for the receiver that best fits your needs.
With that said, the SDS200 does cover those aviation bands and you are correct when you ask about a receiver that is tuned specifically for the air bands receiving better. But it’s not all that much improvement. The SDS200 is designed to favor the 700/800 MHz bands more than the VHF High and UHF Bands where the aviation frequencies reside. But aircraft have line-of-sight with control towers and other aircraft, which means you also have line-of-sight with the aircraft, so any slight degradation in reception with the SDS200 is minimal. It all depends upon if you are looking to monitor other bands and agencies or just civil and military aviation. Once that question is answered you can start your search for the receiver that best fits your needs.
Ubbe
Member
SDS scanners are very sensitive to what kind of RF environment you have at your listening location, much more than any other scanner.
If you have less of local transmitters that doesn't get any stronger than -60dBm then it will help a lot.
SDS scanners have lots of internal spurious signals that interfere and increase in numbers the lower you go in frequency. If you take off the antenna and do a search in different frequency bands you'll see that in the 800MHz band it will stop a few times and hesitate its search but at lower frequencies like VHF it will stop a lot and even open squelch sometimes from those false signals in the receiver chip.
If you do a search in the VHF airband you will find a lot more active frequencies than with any other scanner and that comes from the internal spurious signals that acts as oscillator mixers and lets you hear a transmission at one frequency to also be heard at other frequencies.
The SDS100 and SDS200 use the same receiver solution and design and I tested my SDS100 by injecting a signal in the 800MHz band and tuned the scanner to that frequency and then let the signal generator tune around in the band to see where the scanner would pick up any other frequency, that it shouldn't do if it had a good working receiver. I did this in the 800MHz band as people will usually say that it works good in that band, but it gets even worse in the lower frequency bands.
The filter settings in the scanner, that you can set to Normal and Invert and a few more, will make the frequencies where these interferences appear to change to other frequencies but they will still be there. So you will have to try and use filters, and the IFX feature as well, to try and get the interference to happen on frequencies that you are not monitoring.
drive.google.com
/Ubbe
If you have less of local transmitters that doesn't get any stronger than -60dBm then it will help a lot.
SDS scanners have lots of internal spurious signals that interfere and increase in numbers the lower you go in frequency. If you take off the antenna and do a search in different frequency bands you'll see that in the 800MHz band it will stop a few times and hesitate its search but at lower frequencies like VHF it will stop a lot and even open squelch sometimes from those false signals in the receiver chip.
If you do a search in the VHF airband you will find a lot more active frequencies than with any other scanner and that comes from the internal spurious signals that acts as oscillator mixers and lets you hear a transmission at one frequency to also be heard at other frequencies.
The SDS100 and SDS200 use the same receiver solution and design and I tested my SDS100 by injecting a signal in the 800MHz band and tuned the scanner to that frequency and then let the signal generator tune around in the band to see where the scanner would pick up any other frequency, that it shouldn't do if it had a good working receiver. I did this in the 800MHz band as people will usually say that it works good in that band, but it gets even worse in the lower frequency bands.
The filter settings in the scanner, that you can set to Normal and Invert and a few more, will make the frequencies where these interferences appear to change to other frequencies but they will still be there. So you will have to try and use filters, and the IFX feature as well, to try and get the interference to happen on frequencies that you are not monitoring.
SDS100.mp4
drive.google.com
/Ubbe
Check to see if you have any FM stations near by. I had to get a FM trap filter but now no issues getting civilian aircraft. The antenna you’re using will play a big part too. Are you planning on using an indoor or outdoor antenna?
Thanks for the help, but I won't need it. If i have to do a soft/firm ware update just to get it to recieve NOAA weather, then I just don't have the desire or patience to deal with it. Back to Amazon in the morning along with a db25d that's worthless.
NOAA Weather Radio is a function from Day One with the SDS units. It's a menu function. Above all else.... Before you throw out that scanner, check out what it CAN do! The SDS scanners have a lot to offer, including WX (weather), Air, MilAir, and so on and so forth!
I may feel differently in the morning, I'm not interested in what it can do than what it actually is doing. Which is nothing. Just ordered 2 laptops and SDRs for the new shack for less than the price of the 200. I can do what I want with those easier and quicker than figuring out the 200.
IMHO, you are going to find those SDRs require much more effort to get working than an SDS scanner. But they are likely going to be cheaper.
If you want excellent VHF air, get the Icom IC-R15 and be done....I own one, also from what I have read on this forum, UHF mil is also very good, however, I don't listen to UHF mil.
I'm already using SDRs for trunking. Just going to have some new laptops completely for SDR use. The 10 yo ThinkPad they're replacing will become a full time HF waterfall display until it croaks.
I wanted the 200 to have something that would easily go mobile (MUCH easier than an SDR). I guess I just got a brick, because there's no menu, no 2nd function, and the squelch won't close. It's really nice looking though.
I wanted the 200 to have something that would easily go mobile (MUCH easier than an SDR). I guess I just got a brick, because there's no menu, no 2nd function, and the squelch won't close. It's really nice looking though.
/Ubbe,SDS scanners are very sensitive to what kind of RF environment you have at your listening location, much more than any other scanner.
If you have less of local transmitters that doesn't get any stronger than -60dBm then it will help a lot.
SDS scanners have lots of internal spurious signals that interfere and increase in numbers the lower you go in frequency. If you take off the antenna and do a search in different frequency bands you'll see that in the 800MHz band it will stop a few times and hesitate its search but at lower frequencies like VHF it will stop a lot and even open squelch sometimes from those false signals in the receiver chip.
If you do a search in the VHF airband you will find a lot more active frequencies than with any other scanner and that comes from the internal spurious signals that acts as oscillator mixers and lets you hear a transmission at one frequency to also be heard at other frequencies.
The SDS100 and SDS200 use the same receiver solution and design and I tested my SDS100 by injecting a signal in the 800MHz band and tuned the scanner to that frequency and then let the signal generator tune around in the band to see where the scanner would pick up any other frequency, that it shouldn't do if it had a good working receiver. I did this in the 800MHz band as people will usually say that it works good in that band, but it gets even worse in the lower frequency bands.
The filter settings in the scanner, that you can set to Normal and Invert and a few more, will make the frequencies where these interferences appear to change to other frequencies but they will still be there. So you will have to try and use filters, and the IFX feature as well, to try and get the interference to happen on frequencies that you are not monitoring.
SDS100.mp4
/Ubbe
Kudos on your post! I admire your ability to express fluently the “behind the scenes” goings-on of the SDS series of Uniden scanners (and scanners in general). I never have a problem understanding your meaning when you explain their inner workings. I find myself wishing I could also not only understand the subject matter, (which I have a pretty good grasp of), but put into words that understanding as perfectly as you do. On many occasions I want to further explain the “how and why” of what I’m trying to convey but as hard as I try I find myself “baiting” those people such as yourself into their take on the matter at hand and leaving the explanations, some bordering on the technical, to them. This forum would be at a loss without you and others of the same caliber. Thanks to you and those as informed as yourself for your inputs. Don’t stop anytime soon!
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