Today I saw someone talking on a cell phone in a car with the windows rolled up and the doors closed. It was not a public hazard, because the caller was parked and not moving.
Today I saw someone talking on a cell phone in a car with the windows rolled up and the doors closed. It was not a public hazard, because the caller was parked and not moving.
I came to the conclusion that what I was seeing was impossible. Those little microwaves from a small battery device cannot possibly escape the Faraday Cage imposed by the car’s metal body, and there is no way the signal that does escape could possibly pass through the trees and buildings standing in the way of the cell tower 2-blocks away.
People who think they are speaking to someone from inside a car are having a fever delusion caused by the micro-wave-oven frequency impressed on the side of their head.
If it did work, of course, it could be amazingly convenient.
Cell Phones
Hi Carl!
I don’t like cell phones. However, after years
of not having one, I got stranded somewhere
and really had a problem.
So I got one. I use it as little as possible.
When I tell people that the operating
frequency is not that different from a
microwave oven, they simply do not
understand. They also do not understand
that the cell phone is generating RF
even when you are not making a call.
I don’t know how the cell signals get out of
cars, either. There is a term, that I sort of
remember – it’s something like “RF
apachure.” (SP?) It means that the RF energy can
get out of small spaces if it’s wavelength is
small. And as we know, we are dealing with
very small wavelengths here.
Sometimes, in the ham radio world, a 440 MHz
handitalkie will work better than a 2 meter (144 MHz)
handitalkie.. I have heard stories where a ham is
in a building trying to hit a repeater system. 440 MHz
gets out of the windows better than 2 meters.
Well, that’s it for me.
Best Wishes,
Bruce, DOGGRADIO STUDIO 2
Cellphones in cars
Car bodies are not exactly Faraday cages. The windows are large apertures, RF passes through glass, and the edges of the doors form narrow slot antennas. I’m repeating some things in the previous post.
Escape!!
Yeah, we’re talking about tiny wave lengths, which can escape through almost anything, even metal structures. A hole from a missing rivet or a gap in the weather strip between panels or a door would be plenty big enough.
Years ago I recall an ELT signal (121.5 mHz) set off by a bouncy landing in an aircraft. We (Civil Air Patrol, Lake Tahoe Sqdn) had a heckuvva time locating it even with a couple of ramp drive-arounds (Reno-Tahoe Airport). We heard signal on the East side of Verdi Peak (minerals in the mountain were reflecting the signal) during electronic air search (I happen to have flown that part of the mission).
Turned out it was from an aircraft inside a metal hangar where the door had a slight gap at the bottom. It was escaping under there, well enough to bounce off a mountain twelve miles away!
Now, those units are gradually being replaced by 406 mHz ones. Easier to pinpoint the source, etc.
In large cities where the towers are high up, it’s known that cellular signals spill, rather like a cascade, down the sides of buildings and onto the streets.
Nothing about RF signals surprises me anymore.
What a World
Based on the descriptions of micro-waves that means we are standing and walking in a pool of phone conversations with incessant yakking and jabber 24-hours a day and yet all I actually hear is a plane that’s been cruising the sky for about 5-hours, perhaps a drone-school test plane.
Now I Know How To Spell Aperture – AND
It is interesting that cellphone
signals “spill” down from the towers
and down into the streets.
I had never thought of it that way.
But it makes sense. It’s microwaves –
so it’s really radar – and radar
bounces off of objects. And if the
power is high enough, the energy
keeps reflecting back and forth,
I guess.
Sort of like LIGHT.
Best Wishes,
Bruce, DOGGRADIO STUDIO 2