Page 1 of 1

HF Signals not being received

Posted: Sun Mar 15, 2020 6:03 pm
by LXT118
I am using an RTL-SDR V3, with the long dipole antenna kit.

When I go into the Direct Q Sampling mode, I see AM frequencies, but no CB/hams, etc. In fact, the AM frequencies are reflected to higher frequencies, as well as other signals I am not able to identify.

I'd just like to know if there's anything I can do to fix this. I do realize that I do not have the correct HF antenna for the job, but I'd also like to know if there's anything hardware-related that is causing this reflection issue.

Thanks!

Re: HF Signals not being received

Posted: Tue Mar 17, 2020 3:23 am
by rtlsdrblog
The reflections are just a known part of life with direct sampling mode on the RTL-SDR. To get rid of them you need to use a 14.4 MHz high pass filter.

For CB @ ~27 MHz, you should still be able to receive that in quadrature sampling mode, and that is not affected by reflections.

Ideally you would use a proper CB antnena. But to maximize the dipoles performance extend the long arms out to the max, and put it in a vertical position outdoors.

Re: HF Signals not being received

Posted: Wed Mar 18, 2020 8:55 pm
by LXT118
Thank you, I'll try it!

Update: When I tune into the CB frequencies, the WFM stations are reflected down into its frequencies, so I don't see anything other than FM. Is there any way to fix this?

Thanks

Re: HF Signals not being received

Posted: Mon Mar 30, 2020 3:33 pm
by Username
You can buy a FM Filter from ehre: https://www.rtl-sdr.com/buy-rtl-sdr-dvb-t-dongles/
Mine Work but beware if you want to receive a Frequency above or below the FM Band the will not work. :lol:

I recommend to use a Airspy for CB and HF for me the work the best.

Re: HF Signals not being received

Posted: Thu Apr 02, 2020 3:06 pm
by LXT118
Thank you