Airspy mini vs RTL-SDR

maus92

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Finally got some time w Airspy. First impressions vs SDR. Dx’d some tropo on FMB and P25 TRS. Compares driving a school bus vs sports car, two buck chuck vs a Napa Cab so on. Very fine device.

Trying to figure out what warp adjust did on UT had to go -5.5 to zero in on CC center.
Can’t imagine new device was off frequency.

Yes good times ahead.👏
-5.5 correction is awful large - are you sure you are tuning to the proper frequency? My crappiest Airspy only requires a -1.2 correction, the others are around -0.8 to -0.4
 

Ubbe

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My 5 year old RTL-SDR's both have -1,5ppm correction but I bought two new a year ago and both needs -4ppm correction. That's equal to a +2KHz error at 400MHz and twice that at 800MHz. I don't know why they can't calibrate them more accurate at the factory. Perhaps they have changed a component supplier in the oscillator and didn't care to check if it needed a different value to be used.

/Ubbe
 

rr60

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-5.5 correction is awful large - are you sure you are tuning to the proper frequency? My crappiest Airspy only requires a -1.2 correction, the others are around -0.8 to -0.4
Right? As I adjust warp more negative, it walks IQ right to center. The IQ symbol starts like an eye, as I adjust warp to -5.5, pops up into tightly clustered constellation. P25 LSM. Yes I have tuned on freq. -5.5 warp working for other systems too. New out of box.
 

cabbar

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I have been using both airspy mini and rtl-sdr v3 for about 3 years. In L band, airspy mini gives better results than rtl sdr. 6 mhz bandwidth puts airspy mini in a more advantageous position in the iridium spectrum.Airspy mini and spectrum spy are a perfect duo for finding active stations. I think it deserves every last penny I paid for it.
 

moonbounce

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Just to add my two cents for anyone else who is having the same issues.

I was using RTL-SDR V3 and different versions of SDRSharp to monitor the Mil Air band but I find that SDRSharp doesn't want to play nice. For example, stepping, if I set stepping to 50 khz it will scan in 100 khz steps only, ( SDRSharp 1357 ) if I change stepping to 25 khz it will scan half of the 225 to 380 Mhz in 100 khz and the other half in 25 khz? If I try SDRSharp 1716 in the mil air band the program to scan 225Mhz to 380Mhz it starts out okay but soon changes the stepping from 50 Khz to 12.5 Khz and not only that it will change the mode from AM to NFM, and locksup, even hitting scan won't start the scan. SDRSharp 1275 when stepping is set to 50 Khz it will scan in 10 Khz steps.

I would like to upgrade my RTL v3 to an Airspy Mini hence my presence in this thread, but until I solve SDRSharp problems I guess I will stick with my scanner to monitor Mil Air.

Also when scanning the 225 to 380 Mhz bad with my v3 it will scan right passed the active Mil Air frequency that my scanner is picking up. If I plug that frequency into SDRSharp I will hear the audio but at a much weaker volume than what my scanner is blasting out in the next room.

Anyways that is my gripe, hope it helps someone else, just be aware of strange actions.

Moonbounce
 
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PDXh0b0

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Just to add my two cents for anyone else who is having the same issues.

I was using RTL-SDR V3 and different versions of SDRSharp to monitor the Mil Air band but I find that SDRSharp doesn't want to play nice. For example, stepping, if I set stepping to 50 khz it will scan in 100 khz steps only, ( SDRSharp 1357 ) if I change stepping to 25 khz it will scan half of the 225 to 380 Mhz in 100 khz and the other half in 25 khz? If I try SDRSharp 1716 in the mil air band the program to scan 225Mhz to 380Mhz it starts out okay but soon changes the stepping from 50 Khz to 12.5 Khz and not only that it will change the mode from AM to NFM, and locksup, even hitting scan won't start the scan. SDRSharp 1275 when stepping is set to 50 Khz it will scan in 10 Khz steps.

I would like to upgrade my RTL v3 to an Airspy Mini hence my presence in this thread, but until I solve SDRSharp problems I guess I will stick with my scanner to monitor Mil Air.

Also when scanning the 225 to 380 Mhz bad with my v3 it will scan right passed the active Mil Air frequency that my scanner is picking up. If I plug that frequency into SDRSharp I will hear the audio but at a much weaker volume than what my scanner is blasting out in the next room.

Anyways that is my gripe, hope it helps someone else, just be aware of strange actions.

Moonbounce
In the menu, band plan, click it and uncheck the option to turn it off
 

Ubbe

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but soon changes the stepping from 50 Khz to 12.5 Khz and not only that it will change the mode from AM to NFM,
You will have a file called BandPlan.xml in the SDR# folder. You edit that to suit the bandplan you would like to use. It will look something like this:

<RangeEntry minFrequency="118000000" maxFrequency="137000000" color="900000FF" mode="AM" step="5000">Air Band Voice</RangeEntry>

You can add as much as you like to that file but best are to not do any overlaps of frequency ranges, but I guess it uses the first line that matches the frequency and then skips the rest. So if you add lines at the top it will probably be safe. You set a frequency range and a step size and modulation mode for that specific range, like you can do in some Uniden scanners. Frequencies are in Hz and in the above example it uses 5KHz steps.

/Ubbe
 

moonbounce

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In the menu, band plan, click it and uncheck the option to turn it off
That
In the menu, band plan, click it and uncheck the option to turn it off
I changed the band plan in SDR 1716 but the stepping is still off, instead of 50 Khz stepping I get 10 Khz Stepping, if I change to 25 Khz stepping I still end up with 10 Khz stepping.

I also use SDRSharp 1275 and 1357, with same results as above, can't seem to lock into chosen frequency, and from what I can tell they don't have a band plan like 1716.
 

thewraith2008

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What are you using to scan with in SDR#?
  • Plug-in name and version

To clarify, you need to un-check "Auto update radio settings" in the Band Plan plug-in.
This will then use what SDR# has set for each mode (AM, FM etc...)


Also when scanning the 225 to 380 Mhz bad with my v3 it will scan right passed the active Mil Air frequency that my scanner is picking up. If I plug that frequency into SDRSharp I will hear the audio but at a much weaker volume than what my scanner is blasting out in the next room.
Sounds like you need to enable SDR# AGC.
Also check to see if SDR# "Filter Audio" is enabled.
On AM, SDR# does not remove the offset to the audio without it and the sound is rubbish without it.

First half is without "Filter Audio" enabled:
qtlyK8y.png
 

moonbounce

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What are you using to scan with in SDR#?
  • Plug-in name and version

To clarify, you need to un-check "Auto update radio settings" in the Band Plan plug-in.
This will then use what SDR# has set for each mode (AM, FM etc...)



Sounds like you need to enable SDR# AGC.
Also check to see if SDR# "Filter Audio" is enabled.
On AM, SDR# does not remove the offset to the audio without it and the sound is rubbish without it.

First half is without "Filter Audio" enabled:
qtlyK8y.png
For SDR 1716 I don't use a plugin, auto update not checked, ( never was checked ). I spent all day yesterday making changes, tried with each setting on and off, no change. I have also slowed down as slow as I can get it so I can see it going through the channels and it never hits the spacing correctly.
Right now I am checking out the 138Mhz to 174 Mhz in 5khz stepping, I hit scan, it scans and it stopped on 142.662.5 I hit skip and off it goes but soon changes the stepping to 12.5 khz all by its self?
Right now I have been checking the other two SDR version that I use and they seem to be working okay in the 225 to 380 Mhz, as they scan very fast it is hard to tell, I have tried them scanning as slow as I can get it to scan and they seem to be okay, it is just version 1716 that has the problem.
One question I have is am I the only one who has this problem or are there others that have the problem but don't know it? It is pretty hard to catch if all one does is set it and forget it, maybe it is going unnoticed, just a thought.
 
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thewraith2008

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For SDR 1716 I don't use a plugin
You must be, SDR# doesn't have a built-in scanner.

One question I have is am I the only one who has this problem
Yes.
I know many MilScanners who are happily scanning away.

It kind of sounds like you have inherited someones SDR# installation which maybe:
  • Using an old version of the frequency scanner plug-in
  • Is badly configured
  • Maybe has way to many plug-ins installed which maybe conflicting with each other.
 

moonbounce

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You must be, SDR# doesn't have a built-in scanner.


Yes.
I know many MilScanners who are happily scanning away.

It kind of sounds like you have inherited someones SDR# installation which maybe:
  • Using an old version of the frequency scanner plug-in
  • Is badly configured
  • Maybe has way to many plug-ins installed which maybe conflicting with each other.
You could be right about that, I have downloaded archived copies of some SDR versions, that could be the problem, I really don't remember where I got it from but I will download a new one and see how it works. Thanks for getting back to me.
 

thewraith2008

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Just find an unaltered version of SDR# v1716 to use as a base install.
The Airspy site used to have it, but gone now.
There maybe a link on RR somewhere (or someone can post link again here)

Then use link below to download and then install the updated Frequency Scanner plug-in.

NOTE: Don't go installing every plug-in under the sun. This will lead to disappointment, guaranteed.



Various updated SDR# plug-ins can be found here: MEGA - Download
These plug-ins have documentation for installation and usage, please read.
 

moonbounce

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Just find an unaltered version of SDR# v1716 to use as a base install.
The Airspy site used to have it, but gone now.
There maybe a link on RR somewhere (or someone can post link again here)

Then use link below to download and then install the updated Frequency Scanner plug-in.

NOTE: Don't go installing every plug-in under the sun. This will lead to disappointment, guaranteed.



Various updated SDR# plug-ins can be found here: MEGA - Download
These plug-ins have documentation for installation and usage, please read.
Thanks again, I will see if I can find SDR 1716.
 

wagros

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Just find an unaltered version of SDR# v1716 to use as a base install.
The Airspy site used to have it, but gone now.
There maybe a link on RR somewhere (or someone can post link again here)

Then use link below to download and then install the updated Frequency Scanner

NOTE: Don't go installing every plug-in under the sun. This will lead to disappointment, guaranteed.



Various updated SDR# plug-ins can be found here: MEGA - Download
These plug-ins have documentation for installation and usage, please read.

Allow me to ask a newbie question.
Why use this version #1716 instead of the latest one?
 

thewraith2008

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The plug-ins where updated around the stable versions of SDR# v1700-1716 and will work best with them.
I did do updates to make plug-ins work with later versions of SDR# but this can be hit and miss.

SDR# became unstable for awhile and removed some functionality (e.g. frontends) after v1716.
I didn't like these changes so I didn't use SDR# beyond v1716 therefore didn't spend time seeing if they still worked or not.
SDR# has made some major changes to the UI and other areas of the program (audio level) that have made the plug-ins not work 100% in some cases.
I just don't wish to play a cat and mouse game updating a bunch of plug-ins every time there is a change.

Now there are 64 bit builds of SDR# and the 32 bit plug-ins won't work or load.
 

wagros

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The plug-ins where updated around the stable versions of SDR# v1700-1716 and will work best with them.
I did do updates to make plug-ins work with later versions of SDR# but this can be hit and miss.

SDR# became unstable for awhile and removed some functionality (e.g. frontends) after v1716.
I didn't like these changes so I didn't use SDR# beyond v1716 therefore didn't spend time seeing if they still worked or not.
SDR# has made some major changes to the UI and other areas of the program (audio level) that have made the plug-ins not work 100% in some cases.
I just don't wish to play a cat and mouse game updating a bunch of plug-ins every time there is a change.

Now there are 64 bit builds of SDR# and the 32 bit plug-ins won't work or load.
Thanks a lot for taking the time to answer my question in such detail.
It’d be great if someone from the forum could share a "clean" version of release #1716.
We’ll wait and see what happens.
 
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