[time-nuts] Attenuation of typical roof? (at GPS frequencies)
didier at cox.net
Tue Apr 1 20:59:15 EDT 2008
Some Wi-Fi hardware manuals (haha) have installation instructions and they
give rough indication of the attenuation through common obstacles such as
walls, floors and whatnot. I remember seing one of those not long ago
actually but I have no idea where it is :-(
The frequencies are close enough that it should be a useful indication of
what to expect.
An Internet search on the same subject might yield something.
Of course, every case is different, and before you do a "permanent"
installation, you may want to experiment with a long cable and do some
comparisons using the signal level indications from the GPS data, or let it
run for a dat and find out how much dropouts you got.
> -----Original Message-----
> From: time-nuts-bounces at febo.com
> [mailto:time-nuts-bounces at febo.com] On Behalf Of Hal Murray
> Sent: Tuesday, April 01, 2008 6:11 PM
> To: time-nuts at febo.com
> Subject: [time-nuts] Attenuation of typical roof? (at GPS frequencies)
> Does anybody have any numbers?
> Suppose I have an antenna that is high in my attic. How much
> do I gain by drilling a hole in the roof and moving it up a foot?
> If I knew the answer (even a rough one), I could compare
> various ways to get a few more dB of signal and sort them by
> cost or effort or ...
> Is the attenuation significantly higher when the roof is
> damp? I'm assuming
> a sloped roof so the water won't be very thick. (as compared
> to a flat roof
> that might have puddles)
> How does a wet roof compare to the water in the air when it's
> raining? (or
> fog, snow...)
> Is there a good web site that covers this?
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