Airspy mini vs RTL-SDR

[maus92]

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]

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]

-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]

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]

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

 

[PDXh0b0]

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]

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

 

[Skip_Wilson]

Which Airspy did you purchase please? The website is not updated since 2015.

 

[moonbounce]

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]

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: