Hi There is no need to feed the 58516 or the antenna with any sort of super power supply. It’s just a simple RF amplifier in there. It’s designed to be feed off of the bias supply coming out of a GPS module. If a module has a dedicated 78L05 style regulator on it, it’s one of the better ones ….
Bob > On Sep 3, 2017, at 2:55 AM, Clemgill <clemg...@club-internet.fr> wrote: > > Hi Clay, > Intersting subject. > What design for ultra stable/clean power supply are you using please ? > Thx, > Gilles. > >> On Sep 2, 2017, at 22:47, Clay Autery <caut...@montac.com> wrote: >> >> PCTEL GPS-TMG-HR-26NCM Antenna. >> http://www.neobits.com/pctel_maxrad_gps_tmg_hr_26ncm_high_rejection_gps_p2769137.htm >> >> Can't say what the gain tolerances are, but it appears to be a pretty >> decent quality part. >> >> The distribution amp is an HP 58516A GPS L1 Distribution Amp with the >> external power supply tap which will be fed with an ultras stable/clean >> adjustable linear power supply. As I understand it, this is a unity >> gain amp, so there should be little to no insertion loss or distro losses. >> >> The distribution amp will be mounted near the devices such that amp to >> device jumpers will all be < 1 meter/3.28 feet. Likely a lot less. ALL >> Times N-connectors until reaching a connector TM doesn't make. >> >> ______________________ >> Clay Autery, KY5G >> >>> On 9/2/2017 3:26 PM, Bob kb8tq wrote: >>> Hi >>> >>> A lot depends on what comes after the feed cable. The “disto amp” will >>> determine >>> a lot. You likely need 10 db of net gain in front of it to keep things >>> running ok. For an >>> antenna that is *really* 26 db (as opposed to 26 db +/- 6 db), that would >>> come out to >>> 16 db of feed line loss. This isn’t a terribly surprising outcome. The >>> antennas are designed >>> for installations that run 150’ or more of coax …. >>> >>> Bob >>> >>>> On Sep 2, 2017, at 2:57 PM, Clay Autery <caut...@montac.com> 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 -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.