I tried to collect some meaningful information on making DIY shielding boxes for basic RF experimental circuits and I can't find any definitive guides on how to make them. Every book on amateur RF circuits mentions them as an absolute must but none goes into any details on what metal to use, what wall thickness etc.
Anyways, please give me some guidance on how to make decent DIY RF shielding enclosures for a wide range of the unwanted interference frequencies when designing basic RF circuits.
As
@biastee stated, in most cases it's the seams / seals that you need to pay special attention to. At higher frequencies, even very small gaps can act as slot antennas (i.e. if wavelength is shorter than the size of the aperture), so it's important to know what frequencies you are looking at.
Also, unless your device is completely self-contained / battery-powered and requires no interaction with the "non-shielded" world (control lines, etc.), any penetrations made in your enclosure for passing wires, etc. through will also compromise shielding effectiveness to some degree.
It's also not clear (to me, at least - sorry
) from your post if you are trying to stop signals from entering or keep signals from leaving the enclosure: depending on your use case, the required attenuation might be considerably different. With regard to seams, conductive tape is often very cost-effective if your shielding requirements are modest.