Hardware issues with NooElec NESDR Nano 3, or software?

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Legomaniac
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Joined: Thu Jan 16, 2020 5:50 pm

Hardware issues with NooElec NESDR Nano 3, or software?

Post by Legomaniac » Fri Jan 17, 2020 9:25 pm

Hello everyone,

I recently purchased a NooElec NESDR Nano 3 from Amazon to use with the rtlamr project (https://github.com/bemasher/rtlamr) on my Intel NUC running Fedora 31 (up to date on all packages).

I previously had this set up and working for several months with a NooElec NESDR Nano 2+, (both on Fedora 30 and Fedora 31) however after running somewhat reliably for 3+ months, I started encountering issues where I would call rtlamr and it would never return a response. Looking through my rtl_tcp logs, I started receiving a message every time I started rtl_tcp that it couldn't find a tuner:

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Jan 09 20:09:56 diginuc systemd[1]: Starting RTL-SDR Server...
Jan 09 20:10:11 diginuc systemd[1]: Started RTL-SDR Server.
Jan 09 20:10:11 diginuc rtl_tcp[1294]: Found 1 device(s):
Jan 09 20:10:11 diginuc rtl_tcp[1294]:   0:  Realtek, RTL2838UHIDIR, SN: 00000001
Jan 09 20:10:11 diginuc rtl_tcp[1294]: Using device 0: Generic RTL2832U OEM
Jan 09 20:10:11 diginuc rtl_tcp[1294]: No supported tuner found
Jan 09 20:10:11 diginuc rtl_tcp[1294]: Enabled direct sampling mode, input 1
Jan 09 20:10:11 diginuc rtl_tcp[1294]: Tuned to 100000000 Hz.
Jan 09 23:20:51 diginuc rtl_tcp[1294]: Allocating 15 zero-copy buffers
I then compared this to a friend's NooElec NESDR Nano 2+ that he wasn't using, and found that when I plugged in his unit, I would receive Found Rafael Micro R820T tuner right off the bat. After reading elsewhere that it was likely a hardware issue, I decided to buy the Nano 3. It was only $29.99, so why not?

Yesterday, I received the Nano 3, and it started working. rtl_tcp recognized it, and I was able to get my meter readings from rtl_amr:

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Jan 15 13:32:09 diginuc systemd[1]: Starting RTL-SDR Server...
Jan 15 13:32:24 diginuc systemd[1]: Started RTL-SDR Server.
Jan 15 13:32:24 diginuc rtl_tcp[69409]: Found 1 device(s):
Jan 15 13:32:24 diginuc rtl_tcp[69409]:   0:  NooElec, NESDR Nano 3, SN: 2748882018
Jan 15 13:32:24 diginuc rtl_tcp[69409]: Using device 0: Generic RTL2832U OEM
Jan 15 13:32:24 diginuc rtl_tcp[69409]: Found Rafael Micro R820T tuner
Jan 15 13:32:25 diginuc rtl_tcp[69409]: Tuned to 100000000 Hz.
Jan 15 13:33:20 diginuc rtl_tcp[69409]: Allocating 15 zero-copy buffers
However, it only seemed to work for about 2 hours after I start the rtl_tcp service. I had some other things to take care of, so I didn't get back to troubleshooting until today. It looks like whenever I start rtl_tcp, things seem to work fine for a while (maybe 10 minutes, maybe more than an hour), but then I get quite a few messages of PLL not locked! in the logs, and when I call rtlamr, it just sits there with nothing until I give up:

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[[email protected] ~]# /usr/local/bin/rtl_tcp
Found 1 device(s):
  0:  NooElec, NESDR Nano 3, SN: 2748882018

Using device 0: Generic RTL2832U OEM
Found Rafael Micro R820T tuner
[R82XX] PLL not locked!
Tuned to 100000000 Hz.
listening...
Use the device argument 'rtl_tcp=127.0.0.1:1234' in OsmoSDR (gr-osmosdr) source
to receive samples in GRC and control rtl_tcp parameters (frequency, gain, ...).
client accepted!
Allocating 15 zero-copy buffers
set freq 915700000
[R82XX] PLL not locked!
set sample rate 2359296
[R82XX] PLL not locked!
set gain mode 0
comm recv bye
Signal caught, exiting!
I am wondering if anyone has any tips to help me determine if this is a software or a hardware issue. Because of the problem's transient nature, my current best guess is that the issue with hardware related, and maybe due to the immense amount of heat this thing pumps out.

I have tried with it plugged directly into the NUC, and using a USB extension cable to get it away from NUC's exhaust vents. I have tried in in the front USB ports of the NUC as well, but it always seems to only work for a bit, and then stops responding.

Thanks in advance for any assistance!

Legomaniac

rtlsdrblog
Site Admin
Posts: 2705
Joined: Mon Nov 19, 2012 11:54 pm

Re: Hardware issues with NooElec NESDR Nano 3, or software?

Post by rtlsdrblog » Tue Jan 21, 2020 6:01 am

The first Nooelec Nano dongle must have been faulty, since the error "No supported tuner found" usually means a failed R820T2 tuner chip.

The second unit, i'm not sure if it's a hardware issue. The Nano dongles do get very hot and they don't have enough metal to sink to, so try running a fan over it. Double check that your USB power supply is stable.

You can also try a slightly different branch of rtl_tcp that we have at https://github.com/rtlsdrblog/rtl-sdr-blog.

Legomaniac
Posts: 3
Joined: Thu Jan 16, 2020 5:50 pm

Re: Hardware issues with NooElec NESDR Nano 3, or software?

Post by Legomaniac » Wed Jan 22, 2020 4:04 pm

Hey, thanks for the reply.

Honestly, I don't know what is different from when I was experiencing issues, but I have been running with the Nano 3 for 4+ days now, and it has been fine.

Out of the two back USB ports on my NUC, one is a Z-wave stick on a USB extension cord for controlling my lights and appliances, and the other is the Nano 3. After fiddling around with various set ups of using a powered hub, using one of the front USB ports, running without the Z-wave stick, running with it... I finally got it stable, but I'm not quite sure what made it stable.

Perhaps it's the fact that I switched to a shorter USB extension cable on the Z-Wave stick? That's the only thing I can think of that's different from how things were set up when I was experiencing issues.

Right now, the Z-wave stick's USB extension cord is plugged into the bottom USB port, and the Nano 3 (with attached heatsink) is plugged into the top. rtl_tcp doesn't seem to be throwing any errors, and my Python daemon that calls rtlamr is calling it once every minute, and succeeding each time. It's still running quite warm, but honestly as long as it is stable, I really don't mind as it is in the corner of my living room.

Thanks again for the reply, hopefully it remains this way so I don't have to come back asking for help!

rtlsdrblog
Site Admin
Posts: 2705
Joined: Mon Nov 19, 2012 11:54 pm

Re: Hardware issues with NooElec NESDR Nano 3, or software?

Post by rtlsdrblog » Fri Jan 24, 2020 2:54 am

Maybe the Z-wave stick was causing power ripples on the USB power lines, causing the dongle to disconnect. Or maybe it was taking up too much bandwidth, and now you have them on separate internal hubs that don't share bandwidth.

Legomaniac
Posts: 3
Joined: Thu Jan 16, 2020 5:50 pm

Re: Hardware issues with NooElec NESDR Nano 3, or software?

Post by Legomaniac » Sun Jan 26, 2020 12:35 am

Hmm, the ports I'm using now are the same as the ports I was using when I was experiencing issues. I would think the internal hub would remain the same if the ports used are the same, unless it's something virtual that I am not quite understanding.

Both are the rear, USB-A ports on the NUC. Honestly, the only difference is that the USB extension cable I'm using with the z-wave stick is quite a bit shorter. Maybe the decreased resistance in the shorter cable is the only thing making it stable?

Regardless, thanks for the suggestions!

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