Official bladeRF forum

Hi. After having a power issue with my first BladeRF I ordered and received an exchange BladeRF. Currently I am taking my time to install and use the BladeRF but I do not think that what I receive is what I want.

All is tried on both SDR Console and on SDR Sharp software and the same issue appears on both software.

No matter what samplerate and no matter what gain settings I use, signals appear multiple times on the waterfall. For example the ship traffic in the 162 MHz band with the AIS transponders on 161.975 and 162.025 MHz appear all over the band. Also on the airband signals appear multiple times. I have seen NOAA satellite transmissions 4 times on my waterfall today for only one satellite pass.

I have the BladeRF connected to an USB3 port. Changing it to an USB2 port did not solve the problem.

I attach some images and I hope there is a logic explanation and solution for this problem. I allready re-installed the software and had the BladeRF updated with no improvement.

Thanks for your replies,

Ben

Hi Jon.
Thanks for your reply,

For all the posted images I did set the samplerate to 1 MS/s and the bandwidth to Auto.

This morning I tried for example the airband 124 MHz with 6 MSPS and auto and with 6 MSPS and 3,84 MHz bandwidth but the only difference is that I receive more signals in that range, all with their unwanted mirror signals.
See the attached file: my BladeRF info:
bladeRF> info

Serial #: c7a6dce3cfffc7bfa8a296644f679837
VCTCXO DAC calibration: 0x90c0
FPGA size: 40 KLE
FPGA loaded: yes
USB bus: 0
USB address: 2
USB speed: SuperSpeed
Backend: Cypress driver
Instance: 0

Edit: Tried the same setup with the WinUSB driver , no change. Then I removed the Transverter board and also that makes no difference (except that reception starts @ 300 MHz)


Regards,

Ben

Hi Jon,
thanks again for your reply.

I did make a record with SDRSharp of s DMR repeater on 438.375 MHz. On the screenshot below you see the signals disappearing after the repeater (at 12 miles distance) switches off. I expect only to see the main carrier but I notice 5 "strange" signals around. https://dl.dropboxusercontent.com/u/110 ... 0Hz_IQ.wav
It does not make a difference which antenna I use. I have it connected to a Logper 100 - 1300 MHz vertical, after an FM trap followed by a -3dB splitter. I also tried it with the Diamond V-2000 and with a mobile roof antenna, All stronger signals appear multiple times.

In the jpg image on 124 MHz with 6MSPS and 3.84 MHz bandwidth I expect to see carriers appearing and disappearing on the airband frequencies. However, just like in the 438375 example above, multiple carriers for each airplane appear and disappear. Setting vga to 3 dB (vga1 and 2) and LNA off does not solve this, the stronger signals still behave the same.

I have a HackRF but currently no Linux running. I did have a radiosonde with 100 mW transmitter at 405 MHz. I disconnected the antenna from the BladeRF and moved the radiosonde 10 meters away on the ground floor. 2 times concrete between the bladerf and the radiosonde. Still the main carrier shows up 5 to 7 times on the waterfall. Same transmitter on Airspy or SDR dongle only show up once.

As a try I did run the cli and used the calibrate command, I paste the before and after values, hope that's of any help.
Kind regards,

Ben

Thanks again Jon, you are taking support very seriously !

Kind regards,

Ben

I have the same problem with mine bladerf. I am tried to make auto calibration as written in wiki. But it doesn't help. I don't have Linux at my PC, so I cannot using GNU radio for making manual correction. To me is not clear reason, why I should seen mirror signals at 444 mhz instead real at 436 mhz. In few replies above somebody promised to help to solve this problem. But no answer since 2013.

I think you're looking at the wrong timestamp
2013 is the year jinik joined this forum. But this thread is pretty recent (initial post from Nov 04, 2015)

jynik wrote:Hi Ben,

Brian (bpadalino) has tracked this down to a ferrite bead on the board. Removing it and shorting its pins appears to work around the issue; a number of kind folks on our IRC channel have made this modification and reported that they too see that the spurs no longer occur.

As I don't know FB on the board needs to be removed off the top of my head, I've asked bpadalino to add this to a wiki page, which I will link from here for you.

Best regards,
Jon

Hi Jon,

any link available for me ?

Kind regards,

Ben

Jon,

I have had email contact with Brian who helped me out of my problems.

I replaced FB12 and Z6 and Z7 with a drop of SN40PB60

Now, I don't see the "spurious" anymore and I can see weaker signals near stronger repeaters instead of 4 times the strong repeater.

It bothered me a long time but now it's gone.


Thanks for the support !

Ben - PE2BZ

Does this issue affect all boards? And is the remedy the same if so?