RTL-SDR great on civ air, not on mil air

[RichM]

Just a quick follow up. I’ve got it working quite well now by making a few adjustments. First was turning down the gain. My SNR is close to perfect now and that has really helped. Also I lowered the sample rate a bit to help out my old laptop. Doing this enabled me to lower my detect rate giving me 10 second band search times which is what I expected to get from this dongle. Also I learned that the SDR has about half the range of my hardware scanners even using the same antenna. This explains much of what I thought it was missing.

SDR fast scanning during a recent air to air combat training session yielded 3 new freqs! I’m quite pleased with this new tool for my monitoring arsenal.

Thanks again everyone for all the help, especially the wraith for writing the excellent fast scanner plug-in.

 

[billythec]

Consider checking your antenna across the frequency ranges using a NanoVNA, you might have some unseen attenuation, SWR, or cable /preamp issues that are frequency sensitive?

 

[RichM]

Consider checking your antenna across the frequency ranges using a NanoVNA, you might have some unseen attenuation, SWR, or cable /preamp issues that are frequency sensitive?

I do well in the MilAir band with my hardware scanners using the same antenna/coax/splitter so I knew that wasn’t the issue, but thanks for the suggestion. The RTL-SDR works fine for basic reception tasks but searching the MilAir band is just too demanding for a $30 TV tuner.

I eventually switched to an Airspy Mini and it solved everything. I now get 2-3 second band search times and it catches everything every time. The RTL-SDR had trouble pulling weak signals out of the noise floor and would sometimes skip over strong active signals. The Airspy‘s range and sensitivity are almost identical to my Pro106 except it searches nearly 35 times faster! You do get what you pay for.

 

[MELERIX]

I forgot to mention that I use an old version of SDR# 1642 as I haven't seen any improvement for my applications using later versions.

/Ubbe

if you like older versions of SDR# try at least update to 1716: https://airspy.com/downloads/sdrsharp-x86-noskin.zip

 

[Ubbe]

I have three versions on my computer, 1642, the latest noskin that probably are 1716 and the latest skinned one and there where something about 1716 that didn't work for me, perhaps a plugin I wanted to use. I will select the appropriate version of SDR# depending of what application I want to use.

/Ubbe

 

[MELERIX]

I have three versions on my computer, 1642, the latest noskin that probably are 1716 and the latest skinned one and there where something about 1716 that didn't work for me, perhaps a plugin I wanted to use. I will select the appropriate version of SDR# depending of what application I want to use.

/Ubbe

1716 is compatible with mostly all the plugins, while versions above that can have issues with some older plugins, but version 1642 is not recommended due have some bugs and compatibility issues.

 

[RichM]

I have three versions on my computer, 1642, the latest noskin that probably are 1716 and the latest skinned one and there where something about 1716 that didn't work for me, perhaps a plugin I wanted to use. I will select the appropriate version of SDR# depending of what application I want to use.

/Ubbe

I use SDR# the exact same way - v1910 for satellite decoding, AIS and ADSB tracking and v1700 for MilAir/CivAir band searching. I tried nearly a dozen different versions looking for ones that work well with my set up. These 2 have been rock solid and work very reliably for my needs, other versions didn’t. Every set up is unique and I think experimentation with different versions/plug-ins is required, there is no “one size fits all” version. YMMV.

 

[Trucker700]

MilAir scan range settings:

Frequency search range: 225.000.000 through 380,000,000 AM
Detector: 200 (it misses more with lower settings and still misses some at this setting)
Bandwidth: 10,000
Step size:25,000
*misses about half of what the hardware scanner hears

CivAir scan range settings:

Frequency search range: 118,000,000 through 136,000,000 AM
Detector: 120-150 (150 is usually more reliable but all day today it has run perfectly at 120)
Bandwidth: 10,000
Step size: 25,000
*catches everything, out performs the hardware scanner like night and day

I have just today got my RTL-SDR that I have had for several years ( gave up on it initially and put it away) and couldn't quite figure out how to get it to scan Airband. I borrowed your settings for Civil Air and I am simply amazed at how well it works. Scan speed just blows away my regular scanners.
I am glad I found your post.
James

 

[RichM]

Glad I could help! That is another great thing about these forums, searching/reading old threads of interest can sometimes provide a road map to success.