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EMI filtering:




Switching power supplies, inverters, and solar charge controllers are just a few of the things that can cause
EMI (line noise) on both your AC and DC power, getting into your radio's receive and making it difficult to
hear people, loading up your waterfall with strong, regularly-spaced birdies.

You can buy filter boards or parts and build your own solution, or find pre-made filters for installing internally
or externally. Many filters work for either AC or DC, but you should always check before buying.

I use Pinfox plastic enclosures for filter construction. They're very well-constructed, strong, and have a
gasket that keeps them fairly waterproof. The downside is the plastic is just slightly thicker than my cheap
nibbler can cut. Metal enclosures aren't very helpful because if you're trying to reduce radiated EMI, you
should be installing the filter inside the box that's making the noise anyway. Plastic boxes are just fine for
blocking transmission of power line noise, as long as you place the filter box close to the source of the noise.

If anyone can find a reasonably-priced hand punch for making 8.5x16.5mm rectangular holes in pastic and thin
metal (for powerpoles) I'd love to know about it.



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EMI can filter:



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last updated 03/28/2025 at 16:20:08 by make_www_index.command version 2025.03.04.A