Date: Wed, 07 Jan 1998 17:08:58 +1030 From: Mike Smith <mike@smith.net.au> To: Michael Hancock <michaelh@cet.co.jp> Cc: Nate Williams <nate@mt.sri.com>, FreeBSD Hackers <Hackers@FreeBSD.ORG> Subject: Re: GPS for xntpd Stratum 1 servers Message-ID: <199801070638.RAA00910@word.smith.net.au> In-Reply-To: Your message of "Wed, 07 Jan 1998 14:24:28 %2B0900." <Pine.SV4.3.95.980107141635.23146A-100000@parkplace.cet.co.jp>
next in thread | previous in thread | raw e-mail | index | archive | help
> In what situations would you need an external antenna? Would I need one > if the Garmin was put into a room on the 15th floor of a 30 floor building > in the middle of the floor farthest away from all windows? As a general rule, you want your antenna to have an unobstructed view of most of the sky. Anything more substantial than paper counts as "obstructed". In your case, I would be putting the entire GPS unit on the roof, and using an RS232-fibre-RS232 arrangement to bring the NMEA data back down to your system. If fibre isn't available, you can do it with a single telco pair as long as you put suitable isolation and lightning suppression on it; even a nearby strike will induce a godawful spike in a 15-storey cable. -- \\ Sometimes you're ahead, \\ Mike Smith \\ sometimes you're behind. \\ mike@smith.net.au \\ The race is long, and in the \\ msmith@freebsd.org \\ end it's only with yourself. \\
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199801070638.RAA00910>