How are the Baltimore riots going?/Any way we can help?

Razer Rayzer at
Sun May 3 10:48:12 PDT 2015

Keep in mind that your phone, smart or not, will be transmitting on a
regular basis trying to poll for cellsites. Encasing your phone in a
tinfoil wrapper or other tightly fitting metal case will SERIOUSLY
affect the Standing Wave Ratio (SWR) of the radiating 'antenna' (now
days, because everyone thought antennas were ugly, or inconvenient
despite the fact they dramatically improve phone performance that's
about every metal part in the phone's chassis), and may shorten it's
life. The communications frequency equivalent of putting a metal object
in a microwave oven.

On 05/02/2015 05:21 PM, Mirimir wrote:
> I don't use smartphones, and so don't know what works best. Searching on
> "detect IMSI catcher" yields hits for Android, but I see no apps for
> iOS. AIMSICD looks like a good app. Maybe someone who knows this stuff
> well can recommend one.
> For the Faraday bag, see
> <>. It's easy to
> test. Just put the phone in the bag, and call it. If it rings, there are
> leaks.
> The hardest aspect is getting good electrical contact on all seams,
> including the access flap. The maximum dimension of any hole in the bag
> must be small, less than an inch. A gap at the seam that's an inch long,
> even if it's very narrow, will leak a lot.
> The other thing to keep in mind is that aluminum foil gets brittle with
> bending, and will crack. So you need multiple layers, and the layers
> must be in electrical contact. Narrow strips of double-stick tape
> between layers are OK to provide structural stability. But it's a trade-off.

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