Faraday Cage (need more sleep)

[malfist]

I had this brilliant idea in that state of sleep where you're still awake and sitting at the computer terminal and clicking the SumbleUpon button 'just one more time' before you go to bed and I got to thinking.

I have this alarm clock that syncs with a satellite to get the time. Sense I moved into the dorm it's had difficulty receiving a signal from the satellite. Where I lived before was a mountainous sparely populated county of about 7,000 (county seat of a little over 2,000) and I had great signal there, where you would least expect it. I go to a public university in a decent sized city, and I believe I could be getting some EM interference from something on campus, in dorm, or from the city (or the chemical agents stored in the nearby army depot, but that's not likely). I've already moved it around in the room (away from microwave, speakers (no CRT)) and put it near the window (which worked once).

I was wondering if it would be possible to build a faraday cage around 5 sides of the alarm clock and leave the top open and that do enough to block out noise but allow signal from the sky. Would that be possible?

Malfist

Please excuse my lack of coherence, I haven't went to bed yet.

[malfist]

It obviously wouldn't be a full faraday. would it still work?

[handy]

Try it & you tell us? :-)

[curuxz]

it would be an alarm clock with a wire mesh around most of it...nothing more lol

The cage principal is based on a full cage, its like saying would my earth wire work if I did not plug it in to the ground...no

Least AFAIK.

[slimdog360]

You could extend the antenna on it. Just a thought.

[Stex]

You could just set the time yourself :lolflag:

Why not put it on a plinth in a metallic bowl so it's at the focal point? Much like a satellite dish.

You could build walls around it to stop horizontal interference. It would pick up signals better, but you wouldn't be able to see it.

[ssam]

try replacing the battery.

i have a radio controlled clock, which was keeping time, but did not adjust to daylight saving hours. when i check the AA battery it was down to about 1.2 volt. with a new battery it picked up the signal fine.

for you actual question, i think a parabolic dish would work best. put the clock at the focus, and point the dish at the time signal source.

[mridkash]

Radio signals of low frequency (below Ghz range, I guess) doesnt make sharp shadows.
Consider light for a moment, its an em wave of very high frequency (order of 10^15 hz) and it forms sharp shadows when subjected to obstacle in path, so in a room full of light you can build a cage with open top to just allow the light from top because light from all other sides will cast a shadow inside.
Now, em waves of low frequency (radio) are not good shadow casters, so a cage will fail to protect radio waves entering through sides.

A better and preferred way is to make an antenna, its primary job is to catch required signal and attenuate others. you can make a full, half or quarter wave antenna to amplify the required signal. you just need to know the frequency of the satellite signal.