On Mon, 02 Apr 2012 15:28:40 -0700, Bob Martin wrote: > Bill-- > > The Thunderbolt wants a higher gain antenna than most standard GPS > receivers. I tried standard Garmin active antennas, and while they > worked (I have a good view of the sky), signal levels could be better. > > Best match probably is something like the HP/Symmetricom 58532A antenna, > which has gain > 30dB -- most "active" GPS antennas are in the 24 - 26 > dB range. > > They're not cheap, but they'll do the job. > > If you have much distance to cover, feed line is of course important as > well -- 9913, LMR 400, good quality RG6, something with low loss at 1.5 > GHz. > > I'm using a 58532A feeding a Symmetricom 58535A active GPS splitter to > run a Thunderbolt and a Datum Tymserve 2100. Feedline is 9913 to the > splitter, and short LMR 195 SMA cables from there. (Yes you can find F > to SMA adapters, on eBay, even though many will shudder at the > concept...) > > 73 Bob K6RTM > > > > On Apr 2, 2012, at 15:01, time-nuts-requ...@febo.com > wrote: > >> ------------------------------ >> >> Message: 4 >> Date: Mon, 2 Apr 2012 17:39:40 -0400 >> From: "Bill Riches" >> <bill.ric...@verizon.net> To: "'Discussion >> of precise time and frequency measurement'" >> <time-nuts@febo.com> >> Subject: [time-nuts] Antenna for t-bolt Message-ID: >> <01ac01cd1119$1c699af0$553cd0d0$@riches-H +0wwilmms3r7s880jo...@public.gmane.org> >> Content-Type: text/plain; charset="US-ASCII" >> >> Hi guys, >> >> I have asked this question several times over the past few weeks and >> get no answer. Have I been ostracized??!! >> >> Question is that I am looking for suggestions for GPS antenna for >> t-bolt. The antenna that I am using now is a no name and I not know >> where it came from! Wonder if a Garman GA-30 will work? >>
I think "any" 5v antenna with a 25+ dB gain would work. But the Tbolt likes a high gain antenna. I'm using Maxrad GPS-TMG-40 (40dB) with N-Conn , in Copenhagen. It works reasonably fine with 25m quality 75ohm cable. It's on the balcony , with an ok view to the south. But absolutely no view north , so a bit of the time only 2 sats active. LH says adev 1.2x e-12 on PPS adev 5.3x e-13 on OSC In my summerhouse i use the "mushroom like" antenna that came with the kit from fluke.l , but i have an extra Maxrad waiting to be mounted. This might be a good choice "eby item : 320881667391". Just key in the # in search This is the symetricom as item : 300571554900 cfo _______________________________________________ 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.
