KSDR device is not working!

Discuss KerberosSDR - 4x Coherent RTL-SDR
Omikron
Posts: 4
Joined: Thu Apr 25, 2019 10:40 am

KSDR device is not working!

Post by Omikron » Thu Apr 25, 2019 11:05 am

Hi,

I received the brand new KSDR device that you sent me.
I followed the step by step instructions found in this video: https://www.youtube.com/watch?v=n5aWrz-42qc
but the device does not work.
I flashed the following image to a Raspberry PI3: https://drive.google.com/open?id=11OJb9 ... Ah_yKgunwe

I see that the program starts. I set the parameters (based on the video) after it started, but I never see the spectrum diagram. I can see no error messages.
I checked the hardware and i can see four blue leds are lit and one white led is also lit. I connected the KSDR (USB micro) to the PI3 with a USB cable.

The Raspberry PI3 has received a strong Power Supply Unit, so we can exclude that it is an energy problem.

We followed the instructions that we found on your website (https://www.rtl-sdr.com/ksdr/), many times over, but we received the same results every time.

Please provide me assistance, how I can use this device, because currently it is unusable.

Best regards,
Greg

rtlsdrblog
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Re: KSDR device is not working!

Post by rtlsdrblog » Fri Apr 26, 2019 4:10 am

Hi Greg, i've moved this into the KerberosSDR forum.

Can I please know:

1) When you click start, do you see an update rate in the software?
2) You did not mention anything about the KerberosSDR power supply. How are you powering the KerberosSDR?
3) Did you run the rtl_tests and confirm that you received no errors?

Omikron
Posts: 4
Joined: Thu Apr 25, 2019 10:40 am

Re: KSDR device is not working!

Post by Omikron » Fri Apr 26, 2019 1:16 pm

Hi!

I connected the external PSU to the USB-C port, and the device is working rigth now.
I wanted to use an 868MHz direction measurement with four measuring antennas.
I tuned the four measuring antennas, they are resonant on this frequency, so we can exclude that the antennas are faulty.
As a transmitter, I used an 868 MHz CW transmitter. I corrected the difference between the receiver and the transmitter frequency, and I set the Kerberos center frequency to 867.967 MHz.

Further settings:
The 4 receiver antennas were arranged in a rectangle shape
with: uCA mode, spacing 0.32, all checkboxes ticked exluding FB Average.
Sampling Freq: 1,024MHz
Filter BW: 30kHz
FIR Tap Size: 100
Decimation: 1

With these settings, when I was watching the compass, it oscillated randomly.
What kind of settings could you recommend, that would enable the configuration to work?

rtlsdrblog
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Re: KSDR device is not working!

Post by rtlsdrblog » Fri Apr 26, 2019 1:42 pm

Good to hear that it runs now. You will definitely need to power the KerberosSDR when using a Pi3. There is no way the Pi3 USB ports can provide enough power.

For DOA, did you perform the Sync calibration first? Is the unit in sync and phase calibrated?

bevets
Posts: 1
Joined: Sat Apr 27, 2019 6:05 pm

Re: KSDR device is not working!

Post by bevets » Sat Apr 27, 2019 6:22 pm

Help.

My KSDR seems to be dead on arrival. I am powering it with usb-C 5V/3A. I have tried both raspberry pi images, the 1.2 tinkerboard image (I have both computers), I have built a Docker Ubuntu 18.04 with the install instructions to run on my laptop. I have followed the youtube init instructions.

Both raspberry pi and tinkerboard systems boot up and create a hotspot. Connecting from firefox or chrome from my ubuntu laptop or the microsoft edge browser in a virtualbox all display the init page, but there is no update rate displayed and no graphical output. I can change frequencies etc and clicking save or whatever results in a quick message at the bottom about connecting. Direct usb connection to my docker setup on my laptop says no device found when I run the test scripts. running "lsusb" after plugging in the device shows nothing there.

I cannot login to either SBC system via ssh using the passwords provided (the username is missing in the instructions for the tinkerboard online). The raspberry pi does not produce HDMI display output ... even though the hotspot is alive.

I have switched the dip switched both ways.

What next? Can I get this replaced if I'm out of ideas?

Steve

rtlsdrblog
Site Admin
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Re: KSDR device is not working!

Post by rtlsdrblog » Sun Apr 28, 2019 3:01 am

bevets wrote:
Sat Apr 27, 2019 6:22 pm
Help.

My KSDR seems to be dead on arrival. I am powering it with usb-C 5V/3A. I have tried both raspberry pi images, the 1.2 tinkerboard image (I have both computers), I have built a Docker Ubuntu 18.04 with the install instructions to run on my laptop. I have followed the youtube init instructions.

Both raspberry pi and tinkerboard systems boot up and create a hotspot. Connecting from firefox or chrome from my ubuntu laptop or the microsoft edge browser in a virtualbox all display the init page, but there is no update rate displayed and no graphical output. I can change frequencies etc and clicking save or whatever results in a quick message at the bottom about connecting. Direct usb connection to my docker setup on my laptop says no device found when I run the test scripts. running "lsusb" after plugging in the device shows nothing there.

I cannot login to either SBC system via ssh using the passwords provided (the username is missing in the instructions for the tinkerboard online). The raspberry pi does not produce HDMI display output ... even though the hotspot is alive.

I have switched the dip switched both ways.

What next? Can I get this replaced if I'm out of ideas?

Steve
Sounds like a microUSB cable issue. Can you confirm that you are using a high quality cable? Did you try turning all off, except for one unit, and seeing if rtl_test runs? On the Pi 3, if you connect a keyboard you can also run rtl_test there.

There is no SSH, those login details are for VNC.

zanco
Posts: 8
Joined: Fri Apr 26, 2019 5:31 pm

Re: KSDR device is not working!

Post by zanco » Sun Apr 28, 2019 10:51 am

Not adding much to this topic, but I had two micro USB cables with 1m50 length ordered for my Adalm Pluto and HackRF but both cables only had the + and - connected and no data connection.

They where advertised as "micro USB charger cables" so when I connected my phone with it to the computer also only the phone was charged and no USB connection was made.

I have a lot of short pieces of cable now in the dustbin....


Kind regards,
Ben

rtlsdrblog
Site Admin
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Re: KSDR device is not working!

Post by rtlsdrblog » Sun Apr 28, 2019 11:29 pm

Yeah there are a lot of microUSB "charger only", and microUSB cables with very very thin data line wires out there. So finding a proper microUSB cable seems to be a challenge these days.

In the next batch we're probably going to go all USB-C, as the quality of USB-C cables should be much better.

Omikron
Posts: 4
Joined: Thu Apr 25, 2019 10:40 am

Re: KSDR device is not working!

Post by Omikron » Mon Apr 29, 2019 1:40 pm

Thank you for your ideas.

Today I performed measurements on open ground, to find out how precise the KerberosSDR was.
The transmitter was a PMR radio, distanced 13 meters from the receiver.
Both the receiver and the transmitter and the antennas of the Kerberos were 3 meters above ground.
The receiver had four tuned ¼ wavelenght antennas (SWR 1.2 max).
We had only trees in our environment, there was no metal or concrete around the 100 m distance of the RIG/Kerberos.
We performed Simple Sync and Calibrate IQ.
The antenna gain was set to 3.7 and then 28 on several trials.
The antennas did not receive metal counterpoise, as it is show on the pictures. We placed the antennas in 0.35 λ distance in a row.

During our measurement, we observed the compass to jump between 25-44 degrees.
In another measurement the compass showed values between 37 and 79 degrees.
My question is the following: is it possible to achieve precise direction detection using CW, where the direction of angle is less than 1 degree?
Is it possible to increase the speed of measurement to at least 2Hz? (2 measurements / second)
The way I see it, currently it is not suitable for precise direction measurement, provided that we did not do anything wrong.
I have attached the printscreens of the settings that were applied.

Videos:
https://youtu.be/9a9o2XevCOg
https://youtu.be/aeDLwyoaG3s
https://youtu.be/3rmOdaC4GD8
https://www.youtube.com/watch?v=hJIBpSWauS4
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Omikron
Posts: 4
Joined: Thu Apr 25, 2019 10:40 am

Re: KSDR device is not working!

Post by Omikron » Mon Apr 29, 2019 1:47 pm

More picture:
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