RTL SDR DVB-T dongle - image rejection problems due to "phantom signal" presence

I am showing here a discovery that I recently made, since I was wondering whz the channel skew calibration in HDSDR was not working.

In fact it was working, but I was seeing a different spike on the 1Mhz wide FFT view.
Only zooming in brought clarity on this problem....

It's a pity, but given the ultra low cost of these dongles it is at least amazing what you can do and for weaker signals operation (as you could see on my other videos) this price is unbeatable...

• Category

  Science & Technology

[HiddenBallTrick]

These phantom signals are a big problem with all sorts of SDR software.  I've seen Flex SDRs throw this problem as well.

[MegaOscarVideos]

Hi, what you mean is image rejection - not phatom signals. It has nothing to do with the software, but with the hardware... :-)

The phantom signals seen and explained in this video are specific to this RTL SDR cheap DVB-T SDRs and do no happen with all other common SDRs around.

Best of all:

This problem has been fixed in the newest Linux and SDR# drivers (but still not in the original ExtioUSRP), since it was just a software issue (some skipped samples, where causing this signal shift)...

[huelbe]

Thank you! I was too a bit frustrated with these phantom signals :(