SDS200 On Aircraft Bands

[WX9RLT]

I have saw many saying the SDS200 is not good on the Aircraft Band. I want to tell you about my experience. I will explain my setup real quick.

• SDS200 with stock antenna (Sitting on the table inside the house)
• Uniden 536 with a special built j-pole that is tuned specifically to the aircraft band. (Antenna is approx 20 feet up)
• Airport is KRFD approx. 20 miles away, thru a big city.
• Both scanners on volume 10 with a squelch of 8.

So I have put both scanners on the tower freq of the local airport.
So they can listen to the same thing at the same time and no scanning.
This way I can get an accurate experience.

The SDS200 on a stock antenna was picking up about 83% more traffic than the Uniden 536 with an antenna that was made for aircraft! (J-pole tuned to air band)
I do not see why people are saying the SDS200 is bad on the aircraft bands. I have saw many people complaining about it. I just wanted to chime in with my experiment and experience.

My SDS200 was picking up 83% more audio traffic on the stock antenna inside, than the Uniden 536.

Now, I am going to flip the antennas around tonight. Switch them around on the scanners. And see how that works.

But I wanted to chime in and let everyone know, I am not experiencing the audio issues on the air bands with my SDS200 and stock antenna.

My audio on the SDS200 with stock antenna is picking up the audio better than the Uniden 536.

How is your audio on your SDS200 on the air bands?
What is your setup?

 

[jonwienke]

It's like the "great on digital but poor on analog" thing. Often repeated, but not founded in fact. I've done head-to-head tests between the SDS100 and the 436 connected to a common antenna so they are getting the same signal, and there was little or no difference scanning the same airband channels.

 

[WX9RLT]

Yeah, same concept.

Weird, because I saw a HUGE difference in mine!

 

[N9PVW]

I'm picking up Monroe, LA airport around 50 miles, Shreveport, LA Airport 70 miles, and 3 small town airports between 6 miles and 29 miles all very good. I do have a D130NJ Diamond Super Discone Antenna up 30 feet.

 

[WX9RLT]

It's like the "great on digital but poor on analog" thing. Often repeated, but not founded in fact. I've done head-to-head tests between the SDS100 and the 436 connected to a common antenna so they are getting the same signal, and there was little or no difference scanning the same airband channels.

What is your setup?

 

[WX9RLT]

Also you did yours via the same antenna.
Did you use a multicoupler? or was it 2 different scan sessions?

I did mine via 2 scanners, listening at the SAME time.
So I knew for a fact that I would or would not hear something.

If I just tossed on the same antenna, to both scanners but did not listen to the same thing simultaneously. I would think nothing was wrong.
(Because the 536 was picking up some, but not all)
But since I did it simultaneously, I was able to hear what I was missing.

If you were listening to yours at the SAME time, to compare if you actually heard it or did not hear it. I am definitely interested in hearing your setup. Because something different is happening.

I am hearing ALOT of stuff with my Uniden SDS200 stock antenna sitting on the desk inside.
Better than my Uniden 536 jpole antenna 20 feet up tuned to air band.

 

[jonwienke]

What is your setup?

For that particular test, I had the 436 and SDS100 connected to the same antenna through a splitter, both scanning the same set of airband channels (ZNY air route IIRC). I had them both recording, and compared the total traffic recorded by each after an hour. The total recorded traffic times were within 1% of each other.

I've since done less formal comparisons of the 436, 536, SDS100, and SDS200 all connected to the same discone through a 4-port Stridsberg, and the results have been similar.

YMMV, there may be individual radios with issues on one band or another, or adjacent-channel signals may affect results in some locations. But as a blanket general statement, saying the SDS radios are bad on airband simply isn't true.

 

[Ubbe]

Both scanners on volume 10 with a squelch of 8.

Is there some specific reason to why you are using such a high squelch setting? Have you tried using a squelch setting of 2?

SDS scanners have a pre-amp and a very narrow AM demodulator filter setting better matched to airtraffic communications and the BCD436/536 use a too wide filter. So the SDS should generally be better at monitoring aircrafts, if there's no interferencies that throws a wrench in the gears.

/Ubbe

 

[WX9RLT]

I wasnt talking bad about the SDS200. I was actually complimenting it on how well it does on the airband

I was thinking about getting that multicoupler and testing it that way.

 

[WX9RLT]

Is there some specific reason to why you are using such a high squelch setting? Have you tried using a squelch setting of 2?

SDS scanners have a pre-amp and a very narrow AM demodulator filter setting better matched to airtraffic communications and the BCD436/536 use a too wide filter. So the SDS should generally be better at monitoring aircrafts, if there's no interferencies that throws a wrench in the gears.

/Ubbe

Nah, I just keep it there because when I scan that is my default SQ level, lol. You are right though, I should knock it down some. But I hear a lot of stuff as is on level 8. So that is why I did it on level 8 for the test. I should knock the 536 down some, see if that makes a difference

 

[N4DJC]

My SDS 200 does pretty well on civilian aircraft bands with the stock antenna. I’m on a direct ATL to CLT path, so hear a fair amount of traffic (ZTL). Flights are down by what? 90%?

 

[majoco]

You can't just set the squelch at a number and expect to hear everything - turn the squelch down until you hear the background noise and it stops scanning, then turn it up again until it starts to scan again - now you'll have maximum sensitivity.

 

[Ubbe]

Uniden uses a table over the frequency ranges and an offset value for the squelch to calibrate it to always have a setting of 2 where the squelch should close and a setting of 1 to open, if there's no big RF interferencies received. Whistler seems to not use that kind of compensation, that also most commercial 2-way radios use, and suffers from inbalance in the SQ levels between VHF and UHF. The 536 in AM mode might have a bit too much noise in a signal at SQ level 2 so maybe one click higher would be prefered.

/Ubbe

 

[pb_lonny]

I use SQ4, anything less and it false triggers.

 

[toad99]

I posted a message a while back about TV channel 13 interfering with airband communications. It affected my SDS200, 536, and 996XT. Did not affect a 996T as much or a 780XLT at all. If you have a local TV station on channel 13, and use an antenna with any gain, a 213 mHz filter will work wonders. I just use a tee with a 1/4 wavelength coax stub to attenuate 213 mHz. The stub will knock down the TV signal about 30 dB. I guess it's possible that other TV signals could cause problems, but where I am, it's only TV channel 13.

 

[Ubbe]

I posted a message a while back about TV channel 13 interfering with airband communications. It affected my SDS200, 536, and 996XT. Did not affect a 996T as much or a 780XLT at all.

The 780 uses narrow band filters the other do not. The ch13 signal are overloading the receiver that have filters that pass that frequency.

The stub will knock down the TV signal about 30 dB.

I only manage 20dB attenuation at a lower frequency and I get 10dB notches at frequency multiples and the bandwidth of the stubfilter are +/-15% at the -3dB points. It could hamper your reception at higher frequencies.

/Ubbe

 

[toad99]

Well, my coax stub reduces 213 mHz by 28 db. The bandwidth of the stub is an advantage in this case, with TV channels in the US at 6 mHz wide. Also, the harmonics of the stub at 213 mHz won't fall on anything of interest in the US, being at 639 mHz, 1065 mHz, etc.

 

[jonwienke]

The diameter of the coax used for the stub affects the sharpness of the filtering effect. Smaller coax makes narrower filters.

 

[qcatisvis10]

My understanding of the SDS200 is that it has the same internals as my SDS100. To my disappointment, Aviation reception is dramatically inferior even with a longer antenna than my old Icom A23 transceiver. I'm unable to hear any ATC transmissions from the airport I fly out of with Uniden that appear without trouble using the rubber ducky antenna of the A23. Otherwise I'm happy with it.

 

[AB5ID]

My understanding of the SDS200 is that it has the same internals as my SDS100. To my disappointment, Aviation reception is dramatically inferior even with a longer antenna than my old Icom A23 transceiver. I'm unable to hear any ATC transmissions from the airport I fly out of with Uniden that appear without trouble using the rubber ducky antenna of the A23. Otherwise I'm happy with it.

Maybe a FM broadcast band filter would help?