External LPF / Attenuation

Useful information regarding antennas for SDR products.
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n8me
Posts: 6
Joined: Thu Dec 17, 2015 9:58 pm

External LPF / Attenuation

Post by n8me » Mon May 28, 2018 11:38 am

The white paper on improving LF performance on the RSP1A suggests using an external LPF and attenuation on the Hi-Z input of the RSP2. Is there any information about building or buying such filter?

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g1hbe
Posts: 494
Joined: Sat Jan 17, 2015 3:28 pm
Location: Cheshire, UK

Re: External LPF / Attenuation

Post by g1hbe » Tue May 29, 2018 7:25 am

I've never had to put attenuation on the Hi-z port as I find the range of the RF gain slider is plenty enough. A set of filters is a good idea. I use a LPF to roll off everything above 500KHz when I'm looking for NDB's (200 to 500 KHz) and another LPF which rolls off at 100 KHz when I'm looking for VLF signals. They help a lot in keeping images out and they also reduce the noise level.
If you are handy with a soldering iron you can make these filters quite easily. If you would rather buy, ask on the SDRPlay Facebook page and I'm sure you'll get lots of advice.

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Andy

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