I'm toying with the idea of trying to share a single PCTEL GPS antenna three-ways.
I would prefer to NOT have to put up three different GPS antennas, have three different feed lines coming into the shack, et al. Need to feed: 1) GPSDO (currently a re-purposed Nortel unit) 5VDC spec antenna 2) NTP Stratum 1 server (Raspberry Pi-based) Pretty sure a 3.3VDC antenna 3) Blitzortung System BLUE lightning detection/reporting station. 3.3VDC antenna PCTEL GPS-TMG-HR-26N antenna is a 5VDC nominal (40mA @ 5VDC) HOWEVER the spec sheet shows it functions from 3.3VDC to 12 VDC using a regulated supply, and a "survival voltage" of 24 VDC. Now, I have heard of folks running antennas that function on 12VDC on a straight splitter with no DC blocking, but that doesn't "sit right" with the OCD over-engineer part of me. Here are the 3 options: 1) 3-way split, no DC blocking 2) 3-way split with DC blocking on 3.3VDC devices. 3) 3-way split with DC blocking on all three devices AND DC injection after the split with a chosen regulated DC voltage based on best gain vs. minimized noise. Leaning toward Option #3 because I don't intend to use the old NORTEL unit forever... and it's replacement may well NOT be a 5VDC device... And I suspect that efficiency drops rapidly below 5VDC. That way, nothing changes from splitter to antenna regardless of what device I put in place for GPSDO, NTP server, et al... Cable run will be approximately 53 feet from devices to top of 38 foot mast right outside the shack (top of pole used at one corner of 80m loop; loop is suspended 10 foot laterally away from mast). I know splitting the signal is likely NOT "time Nuts approved" approach, but I'd like to try it anyway... and putting the antenna up high in an all but unobstructed 360 degree view, and using a low-loss feed-line should allow sufficient signal for all devices. (I hope) Any suggestions for a 3 port DC blocked splitter, or other part(s) and some part to use for DC injection? I can handle the linear regulated supply. <wink> Thanks! -- ______________________ Clay Autery, KY5G (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.
