Airpsy Mini on an RPi


#1

I was continuing to investigate why I was having such poor result on my UHF station and noticed that my NooELEC SMArt was hot…very hot when it was plugged into my pc. After restarting it had a nice spike right in the centre of the frequency display so I have come to the conclusion its a bit knackered.

I was going to buy a replacement as they are pretty cheap and had thought about an Airspy mini but remembered some older conversations about the RPI not managing to to keep up with the sample rate. I did notice on their website that they support RPi .

Does anyone know if the issue has gone away?


#2

I want to say my RTL-SDRs (Even new rtlsdr blog branded.) run burn your finger hot after an hour or two. And they work fine. (They also stay pretty stable.)


#3

I’ve swapped it over with the one on my VHF setup too see if there is any difference. It was way off frequency as well after getting to egg boil mode. I think its ok for a muck about but genrally on its way out


#4

My RTL-SDR’s have never gotten “burn your finger” hot, even when i had them running 24/7 as aprs satgates. They do get very warm, though. I used to rubber band them to huge chunks of aluminum and that would drop the temperture even further, down to about 100F (as measured with a thermocouple sandwiched between the two).


#5

Mostly it’s my Adafruit compact one that gets burning fingers hot my other two (one rtlsdr blog and other one Neolect) get hot enough you wouldn’t want to be holding them for long. My one on my station still works well even at the high temps and has been for 2 years now. Plus or Minus the few days of down time in my station.


#6

Perhaps I should just get another cheapo one


#7

I have a RPi 3B+ and an older AirSpy Mini using GQRX. See http://gqrx.dk/download/gqrx-sdr-for-the-raspberry-pi Alex recommends setting sample rate to 3 Msps and input decimation ≥ 8. Seems to work well within those limitations. Yes, it does get warm.
(So does my RTL-SDRv3 on my Satnogs system and my FIAB FCD Pro+). Haven’t verified yet if I can toggle bias-T power on/off yet. I have not tried running it with the Satnogs client.


#8

is it worth the upgrade @ks1g ?


#9

Depends. I had an Airspy Mini I wasn’t using, so the cost to try it with a RPi3B+ was just my time to install a fresh Raspbian image and install GQRX and dependencies. I have not tried it with the Satnogs software, assuming the RPi version even supports it. I’d be more enthusiastic if the Pi could use all of the Airspy’s performance, or I had another small device I could dedicate that could keep up.

As RTL-SDRv3 “just works”, I’d stick with that for my SDR and use the money that would go towards an Airspy towards other improvements in my station. On the other hand, Airpsy has better specs than RTL-SDR, so it might be worthwhile.


#10

I’ll get one and see how I get on. Its the only way to find out really


#11

I too am very interested in if upgrading to an Airspy Mini would give my station a boost in performance.
Will be following this thread closely.


#12

I wonder if the original Airspy would also work. I still have one of those laying around unused…
will set up and try once I moved and also follow this thread closely


#13

I’ve got a mini on the way so we can see if that works


#14

It is here…it is plugged in and in testing on GS33, I’ll report back in a couple of days with testing results


#15

What changes did you make to the satnogs software config?


#16

First off is just a simple change in satnogs-setup, change the rx device to airspymini

I haven’t found the place where sample rates are. The git issue that i found suggested that the sample rates are set in one of the parameter files as they cant be set as an option. I haven’t found that. Gain can be set under the advanced section in satnogs-setup.

I’ve scheduled a few obs to see what they come out like but a non scientific test with gqrx showed it to be way better than the rtl dongle, but then again I would hope so at 5 times the price.


#17

You need to add it in gr-satnogs in hw_settings.py!
See:


#18

I couldn’t see for looking :slight_smile:
Thanks Patrick. I think i should update the wiki at some point


#19

Is there a parameter to set decimation in the hw_setting.py file? I see the python code sets the recommended sample rate. Where do you set the decimation value? Or is it ignored/unnecessary for satnogs?

In GQRX, the way to activate the bias t is to append “,bias=1” to the device string in the GUI settings window. For the satnogs client, I am guessing ‘dev_arg’: ‘airspy,bias-1’ would work.