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RTL_SDR V3 with supplied whip antenna just receiving FM broadcast

Posted: Wed Apr 21, 2021 2:28 pm
by vinloren
I am trying rtl-sdr V3 using Sdrsharp or eirher HDSR SW in Win10 environment using supplied whip antenna but the only broadcasts I can receive (very well) are the local FM station and rarely (less well) some communication in 144Mhz and 433Mhz band. No air band at all nor any HF broadcast whatsoever: just noise. I configured "direct sampling Q branch" to receive HF bands but that didn't help. I suspect the dongle is saturated by the FM stations in my area since I receive images of FM broadcasts in 25Mhz band so I wonder now if a notch FM filter (such as Flamingo) would actually solve the issue but I'd like to have a confirmation on this by anyone who came across this experience before investing additional 25$ to the initial 28$ dongle cost.

Re: RTL_SDR V3 with supplied whip antenna just receiving FM broadcast

Posted: Thu Apr 22, 2021 3:45 am
by rtlsdrblog
The included antenna is not sized for HF, you'll need a much larger antenna for that. There is already a good FM filter on the direct sampling circuit, so you shouldn't need another unless you're very close to an FM tower.

For the AM band you can expand the long elements almost to the max for best performance. Of course the antenna must be outside for best performance too. An airband bandpass filter is best if you're interested in the airband specifically, but an FM filter can also help.