RTL-SDR with Frontend Bandpass Filter
Over on YouTube Adam Alicajic has posted a video showing how much a bandpass filter at the front end of an RTL-SDR can significantly improve reception. He points out that it is a myth that modern software receivers do not need preselector filters at the front end for best performance.
He tests the RTL-SDR with and without a front end 2m triple helical bandpass filter on a CW beacon at around 144 MHz. With the filter on there is almost a 10dB improvement in signal reception.
“He points out that it is a myth that modern software receivers do not need preselector filters at the front end for best performance.”
Yes, in the video he does say that! Gee, and with no source citation. Anyone knows such a statement from a Systems Engineering standpoint is nonsense. Filtering, properly done, is often your friend – if not unavoidable.