Faraday bag against a raspberry

[epigramx]

I noticed that a raspberry (and a powerbank) inflict serious interference to a gnss module/antenna above it and using a regular antistatic bag under that antenna/gnss module improves the gnss signal quality significantly.

I wonder on the best practices to shield the receiver. If I wrap the raspberry in a regular antistatic bag, will the small holes for the connections leak a lot? Is it enough to just lay the bag under the antenna?

[Whales]

It's worth noting that 'near field' and 'far field' interference interact differently. 

If it's near-field magnetic then a layer of metal (eg ESD bag) between the two might improve things, even if there are gaps around the sides.

Also be wary that your faraday bag is becoming part of your antenna.  Check what type of mounting your antenna is designed for -- onto metal ground surfaces or is it designed for use far away from anything metallic?  Balanced or unbalanced antenna?

[ogden]

Aluminium foil is way better quick & dirty, low cost shielding solution. Make sure you get as thick as you can find.

[radiolistener]

If I wrap the raspberry in a regular antistatic bag, will the small holes for the connections leak a lot? Is it enough to just lay the bag under the antenna?

it's better to use copper foil. Something like that: https://www.aliexpress.com/item/99-9-High-Purity-Copper-Sheet-Cu-Metal-Flat-Foil-0-2mm-Thickness-Pure-Copper-Plate/32882328573.html

You're also should note, that interference can go through wires (power or signal).

Small holes will not affect significantly.

[epigramx]

layer of metal

Aluminium foil is way better

it's better to use copper foil.

I did use a copper-clad board before I tried the antistatic bag and it improved almost nothing. I suspect the EMI/RFI from the raspberry or/and powerbank affects the "new ground plane" formed by the copper board while an antistatic bag because of its irregularity keeps it not part of the antenna somehow.

faraday bag is becoming part of your antenna.

I have doubts on that because a copper-clad board (which I tried) has completely different behavior (it seems to not be an improvement against EMI/RFI). Bags appear to not be antennas [maybe their shielding is too irregular to act like that or there's another factor].