[TenTec] GPS Antenna feedline

[Eric F. Richards]

At 06:58 AM 6/24/2003 -0400, you wrote:
>At 12:49 PM 6/23/2003 -0400, you wrote:
> >I received my HP Z3801 last week. To keep things on topic, the intent is to
> >use it as an external reference for my RX340.
>It's RF related and that's close enought for me!!!
>
>As one of those 'radio guys' at the tower sites, I see these GPS antennas
>frequently. Paging services use them for syncronization of their
>transmitters. Cell carriers use them for E911 calls and many broadcast
>stations use them for their frequency standard.

CDMA sites also use them for frequency standard -- for coordinating handover
and the frequency hopping?  Dunno.  But that's where these come from.  To
those who haven't already set up your GPS, before you reset it, ask for a
status to get the coordinates of where it was last installed.


>  30' feedlines are common
>and 50' runs are not uncommon. For shorter (<25') runs 1/4" hard line is
>the norm and out to 50' 3/8" is often used. As with any tower/cell site
>installation, a Polyphaser lightning protection device is in line at the
>shack entrance.

Remember to get a Polyphaser that passes DC so that the preamp gets power
from the GPS.  The more common (to ham users) Polyphasers block DC.  There
are specific narrow-band ones for GPS, though, IIRC.

Eric


-- 
Eric F. Richards
efricha at dimensional.com
"The weird part is that I can feel productive even when I'm doomed."