[time-nuts] Attenuation of typical roof? (at GPS frequencies)

Didier Juges 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.

Didier KO4BB

> -----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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