• Effective immediately we will be deleting, without notice, any negative threads or posts that deal with the use of encryption and streaming of scanner audio.

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Need some SWL info.

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Jan 18, 2010
Hey guys,
I've been thinking about getting into SWL,and just wanted to know if there is a real world of difference in
getting a receiver that only has PLL,or one that has PLL and DSP?
Any info is appreciated!!


Wiki Admin Emeritus
Jul 22, 2002
Bowie, Md.
This is a tough question to answer, since DSP can be used in many different ways.

DSP can be used for audio processing (the R75 uses this for noise reduction and notches). There are software defined radios that are DSP driven. It's really a preference that a person has to make for themselves - if it's used like in the R75, it takes a fairly good ear, and lots of patience, because it can make the signal sound worse if not adjusted properly (I've played around a little with it, but not much...). Once adjusted properly it can really be helpful

I'll let the R75 folks argue the merits of the DSP unit - it's pre-installed by Icom - and I'd throw a question or two on our Software Define Radio forum (we have a separate forum for both) if you're interested in either. At least to me, audio recovery is the real key here - does it make a weak signal sound better (not stronger - that's not the same thing)? Does a fairly solid signal sound natural, or metallic? How is the DSP implemented? These are fairly important questions to answer.

It's a toss up, frankly.

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