Airspy R2 for aviation monitoring

[KSM0Scanner]

I recently dipped my toe into SDR, starting with an Airspy R2. My interest is mostly in aviation monitoring and SDR seems the way to be going, but I admit there has been a bit of a learning curve for me. So far, I have gotten it working well with SDRSharp and Frequency Scanner Plugin on the civil side of things and getting good reception down in the 118-136, but it seems absolutely deaf on 225-400. If I plug the antenna into a BC9000xlt next to the R2 I'll hear tons coming through on 225-400 very clear, but the R2 is missing 100% of it. I am using the same bandwidth of 12,000 and step size of 25,000 for both ranges along with the same gain settings. I have tried the setup at both my home in metro KC and at another remote location with low RF noise with the exact same results. Any ideas of what I might be doing wrong?
thanks,
Gregg in KC

 

[Reconrider]

Try SDR++ and never go back to bloatware we call SDRSharp

SDR++

SDR++ The bloat-free SDR receiver

www.sdrpp.org

 

[mtindor]

Try SDR++ and never go back to bloatware we call SDRSharp

SDR++

SDR++ The bloat-free SDR receiver

www.sdrpp.org

You may be right (I have never used SDR++), but what does this have to do with the OP's current issue? Using SDR++ (over SDRSharp, authored by the same person who actually developed the Airspy line) isn't going to magically make Airband signals pop out of thin air.

As far as the OP's question, I have no idea what is going on but in general there is no appreciable difference in performance between VHF and UHF Airband assuming the antenna is good for UHF airband.

 

[dlwtrunked]

I recently dipped my toe into SDR, starting with an Airspy R2. My interest is mostly in aviation monitoring and SDR seems the way to be going, but I admit there has been a bit of a learning curve for me. So far, I have gotten it working well with SDRSharp and Frequency Scanner Plugin on the civil side of things and getting good reception down in the 118-136, but it seems absolutely deaf on 225-400. If I plug the antenna into a BC9000xlt next to the R2 I'll hear tons coming through on 225-400 very clear, but the R2 is missing 100% of it. I am using the same bandwidth of 12,000 and step size of 25,000 for both ranges along with the same gain settings. I have tried the setup at both my home in metro KC and at another remote location with low RF noise with the exact same results. Any ideas of what I might be doing wrong?
thanks,
Gregg in KC

What antenna?

 

[KSM0Scanner]

I tried various that all perform well for me on my BC9000xlts and BC780s, but I started with the DPD OmniX first. Same results no matter what antenna I use. If I simply move the antenna from the scanner to the R2 I hear nothing in UHF. When I put the antenna back on the 9000, it's party time.
Thanks,
Gregg in KC

 

[mtindor]

I never listen to 225-400 mhz military, but since the first Airspy came out i've been using Airspys on 400-475 mhz and they've been stellar. Nothing in the Airspy documentation suggests any sort of blockage of 224-400 Mhz. So it should be performing equally as well across the bands.

So maybe there is an issue with your particular Airspy and some filter that is in place in the Airspy that is not working properly. I don't know. You should test the 400-470 Mhz band (although depending on where you are there may be nothing to hear below 450 or above 465).

Mike

 

[dlwtrunked]

I have use an Airspy R2 on UHF aero for years and it worked fine. (When you say "tons" of activity on 225-400 MHz, that throw me a little as most do not hear all that much. I live near DC and would not call what I hear as "tons".) Something is odd in your experience. I would try different gain setting for VHF and UHF and see if that makes a difference.

 

[RichardKramer]

Are you sure you're not hearing harmonics or images of the civil air band on your 9000xlt?. As dlwtrunked said, military comms in the UHF band usually don't have "tons" of comms like the civil airband. I have my airspy R2 for 2yrs now and it works fine on milair uhf; but I can listen for hours and not hear anything while on the civil air band it's like what you call "party time". If your 9000xlt is busy with milair stuff, are you close enough to an air base that has an Atis freq on UHF? You could get close by and try the R2 on the UHF Atis freq and see what happens. Other than that, as others have said you may have a bad unit.

 

[KSM0Scanner]

I monitor from KC. Activity here runs daily M-F from early morning into the night. Additionally, I have property under the Salem MOA that I monitor from quite often. I am quite familiar with VHF, UHF and scanners and I am not monitoring any harmonics or images. I am not familiar with SDR at all though and it is the only thing in my arsenal that is not working. I can monitor everything perfectly with my scanners, I am only using the new SDR for the fast search feature I have been reading up on. Once I got the gain set to hear the VHF stuff, I figured I would be golden on UHF unless there was a ton of RFI, which there does not seem to be which is what prompted the question. I do figure its operator error.

I say party time because often there are just too many players in the area to keep up with. I consistently hear aircraft at altitude out past Salina and with all the AR tracks and the MOAs around KS and MO some days can be pretty exciting.

Gregg in KC

 

[BM82557]

I also use SDRSharp and the Frequency Scanner Plugin on UHF milair, this is my configuration that works file --

 

[Reconrider]

You may be right (I have never used SDR++), but what does this have to do with the OP's current issue? Using SDR++ (over SDRSharp, authored by the same person who actually developed the Airspy line) isn't going to magically make Airband signals pop out of thin air.

As far as the OP's question, I have no idea what is going on but in general there is no appreciable difference in performance between VHF and UHF Airband assuming the antenna is good for UHF airband.

I have never been to sure of it honestly. I used to do a lot of LBAND stuff for airplanes up in the 6ghz range and sdrsharp would never see the signals. Grabbed sdr++ and it's worked 500x's better than sdr# ever wished it could. I wish it had more features but what it lacks, it makes up in how great of a decoder it really is. I've used the same antennas between both programs and get better results on sdr++. I've used paperclips as a test for both programs and ++ still worked better at signal strength than sdr#.

And yes, I've checked the gain levels to be the same when testing.

 

[mtindor]

I have never been to sure of it honestly. I used to do a lot of LBAND stuff for airplanes up in the 6ghz range and sdrsharp would never see the signals. Grabbed sdr++ and it's worked 500x's better than sdr# ever wished it could. I wish it had more features but what it lacks, it makes up in how great of a decoder it really is. I've used the same antennas between both programs and get better results on sdr++. I've used paperclips as a test for both programs and ++ still worked better at signal strength than sdr#.

And yes, I've checked the gain levels to be the same when testing.

Sorry, but I just don't buy that. SDR++ is not going to do Airspy better than SDR# does Airspy. SDR++ is not going to make signals appear that don't appear in SDR#. If anything it would be the other way around. If you were talking about any other SDR stuff (RTL dongles, hackrfs, RSPs, etc), I wouldn't doubt you because I simply don't use SDR++. But there is no way Youssef is going to develop an SDR device, develop the SDR# software, and then make it so that third party SDR Software (SDR++) works better at pulling in signals from Airspys than SDR# does natively. Does that sound logical at all? And Youssef is a pretty logical guy.

 

[slicerwizard]

I tried various that all perform well for me on my BC9000xlts and BC780s, but I started with the DPD OmniX first. Same results no matter what antenna I use. If I simply move the antenna from the scanner to the R2 I hear nothing in UHF. When I put the antenna back on the 9000, it's party time.
Thanks,
Gregg in KC

It's been my experience that some Uniden scanners have very hot front ends, to the point where they may overload badly on some bands, especially those where you find cellular carriers. SDRs have tamer front ends, so what you report sounds rather normal to me.

 

[ormetkruper]

Too bad there is no web sdr on the spyserver network in your town you could have compare your airspy with. I suppose you are in Kansas City?
Nearest seems to be east in Saint Louis and west of Wichita in Kansas some 200 miles away.

 

[dlwtrunked]

Sorry, but I just don't buy that. SDR++ is not going to do Airspy better than SDR# does Airspy. SDR++ is not going to make signals appear that don't appear in SDR#. If anything it would be the other way around. If you were talking about any other SDR stuff (RTL dongles, hackrfs, RSPs, etc), I wouldn't doubt you because I simply don't use SDR++. But there is no way Youssef is going to develop an SDR device, develop the SDR# software, and then make it so that third party SDR Software (SDR++) works better at pulling in signals from Airspys than SDR# does natively. Does that sound logical at all? And Youssef is a pretty logical guy.

Yep, if someone thinks SDR++ is doing better than SDR#, he is doing something wrong. I have both pieces of software and a dozen Airspys.

 

[BenScan]

I recently dipped my toe into SDR, starting with an Airspy R2. My interest is mostly in aviation monitoring and SDR seems the way to be going, but I admit there has been a bit of a learning curve for me. So far, I have gotten it working well with SDRSharp and Frequency Scanner Plugin on the civil side of things and getting good reception down in the 118-136, but it seems absolutely deaf on 225-400. If I plug the antenna into a BC9000xlt next to the R2 I'll hear tons coming through on 225-400 very clear, but the R2 is missing 100% of it. I am using the same bandwidth of 12,000 and step size of 25,000 for both ranges along with the same gain settings. I have tried the setup at both my home in metro KC and at another remote location with low RF noise with the exact same results. Any ideas of what I might be doing wrong?
thanks,
Gregg in KC

I haven't really done much with conventional scanning with my Airspy R2. I mainly use SDRTrunk for monitoring P25 trunking systems. That program allows you to "play" bunches of channels at one time. However, even though you have say a VHF and a UHF channel playing at the same time, with only one Airspy R2, you're not going to be able to hear both at the same time, since it only covers about 9 MHz at a time. It lets you know this and will give a message like "tuner unavailable" for one of the bands.

I'm not familiar with the software you are using, but if you're trying to listen to both 118-136 and 225-400 at the same time with the only 1 Airspy R2, it won't work, unless the software is truly scanning between the two bands. If you're able trying turning off the 118-136, and only listen to a 9 Mhz range in the 225-400 band where you commonly hear traffic with your other radio(s).

Happy Scanning,
Ben

 

[KE5MC]

Much said about gain, but as I read thru the posts I didn't see anything about squelch setting. I don't know that flavor of SDR software, but sometimes settings are not universal and may be frequency, mode or band specific and change moving around. Squelch set to high and it will seem like a dead radio/band.

Something to check...

Mike

 

[Reconrider]

Sorry, but I just don't buy that. SDR++ is not going to do Airspy better than SDR# does Airspy. SDR++ is not going to make signals appear that don't appear in SDR#. If anything it would be the other way around. If you were talking about any other SDR stuff (RTL dongles, hackrfs, RSPs, etc), I wouldn't doubt you because I simply don't use SDR++. But there is no way Youssef is going to develop an SDR device, develop the SDR# software, and then make it so that third party SDR Software (SDR++) works better at pulling in signals from Airspys than SDR# does natively. Does that sound logical at all? And Youssef is a pretty logical guy.

As said, in my testing it did. Maybe it's my area, maybe I didn't verify the squelch were the same but sdr++ was better. Feel free to download and test yourself.

 

[kb5udf]

For my location getting good performance for MIlAIR with airspy r2 requires filtering. I use an Fm broadcast filter, followed by a mil-air specific filter. With just one of these filters inline, I still get fm broadcast images. Such issues are obviously location specific as I have a few radio stations not far away.

 

[dlwtrunked]

For my location getting good performance for MIlAIR with airspy r2 requires filtering. I use an Fm broadcast filter, followed by a mil-air specific filter. With just one of these filters inline, I still get fm broadcast images. Such issues are obviously location specific as I have a few radio stations not far away.

I live only 0.8 miles form an FM broadcaster with no big problem though I do use an FM broadcast filter. Gain set too high?