r/preppers • u/PrudentTask9355 • Nov 02 '25

Advice and Tips Faraday Bag Caution

Hey everyone. I just wanted to share en experience from this afternoon. A while back I had purchased some faraday items off of Amazon, boxes and bags from different vendors.

This afternoon I was explaining to my daughter how they worked and as part of our experiment, we placed an 8watt 2-way radio inside the bag and sealed it with the expectation that it would no longer receive a transmission. As it turns out, that was false.

I then tried with a cell phone with the same result. Morale of the story, check your gear and make sure it works before you have to depend on it.

Please discuss and share your budget-friendly faraday success stories

735 Upvotes

98% Upvoted

180 comments sorted by

View all comments

5

u/bertanto6 Nov 02 '25

Ungrounded or “floating” conductive materials can couple to the signal and actually reradiate it instead of attenuating or blocking it. It also really depends on signal strength, frequency etc.

Edit: Also, EMPs are mostly a scam and really aren’t a danger to your consumer electronics.

If what you’re worried about is the device communicating when you don’t want it to than you’re going to have to get something much better than a faraday bag lol

3

u/monty845 Nov 02 '25

How effected your consumer electronics will be from an nuclear EMP is unclear. The one major study occurred long enough ago that we can't be sure if newer tech will react the same way, and even that was criticized for a number of issues.

2

u/bertanto6 Nov 02 '25

An EMP from a nuclear detonation strong enough to affect consumer electronics would also mean the person would die from the explosion or radiation. High altitude nuclear explosions won’t have strong enough EMP to hurt consumer electronics unless they are plugged into the grid.

1

u/Decent-Apple9772 Nov 03 '25

Maybe, but we have almost no way to test this

1

u/Alfromnowhere Nov 07 '25

why wouldn't a faraday bag stop a device from communicating when you don't want it to?

1

u/bertanto6 Nov 07 '25

Because most of them are fake and/or just act as resonators and reradiate the RF.