What are you using for a distribution amplifier ? On Sat, Sep 2, 2017 at 11:57 AM, Clay Autery <[email protected]> wrote:
> Having decision-making problems for the materials for my GPS main > feedline. Going to use a TM LMR stock, just can't decide how big to go > with it... > > 26 dB 5vdc antenna on top of a 38 foot mast. Feed will come down the > inside/center of mast and exit near the bottom, thence routed through a > window and to the GPS distro amp. Antenna will feed GPSDO, NTP Server, > Blitzortung System Blue station, and one other device TBD. > > Just cannot decide how big to go with the antenna to distro amp feed... > Assuming 50 feet total (38' mast + 12 feet to amp in shack) @ 1800 MHz > (closest to 1725 MHz), here are the losses from just this piece > (ignoring the amp to device jumpers): > > -240 = 5.45 dB XXX - too much loss? > -400 = 2.85 dB > -500 = 2.30 dB XXX - too hard to find > -600 = 1.85 dB > -900 = 1.25 dB > > Money not necessarily a consideration as this is a short run for a > permanent installation. Don't anticipate ever moving the GPS antenna to > the tower. > For 900 and likely 600, likely would not be able to do it in one piece > as routing it out of the mast and into the shack would get complicated. > Would likely bring it out of the mast at the bottom with a right angle > connector, and then use a smaller diameter jumper for the last 12 feet. > 500 is pretty uncommon stock wise and it and connectors are harder to find. > > I already have the tooling for both 240 and 400... but I definitely > don't want to challenge ANY of the devices for signal gain. > > So it mostly boils down to easy vs. more effort ($$ aside).... Is it > worth the additional trouble to move from -400 to -600 or -900? To NOT > lose the 1-1.6 dB additional? > > I'd appreciate your recommendation and reasoning. Thanks in advance! > > 73, > > -- > ______________________ > Clay Autery, KY5G > MONTAC Enterprises > (318) 518-1389 > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/ > mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
