Hi I think it's safe to say that gain and directivity are pretty closely tied in this case.
An ideal GPS antenna would not have a lot of gain straight overhead. You have less atmospheric loss in that direction. What you would want is an antenna that has some gain at 30 to 60 degrees. That was the issue with the helix antennas. They have gain straight up (and thus less at other angles). Bob On Oct 10, 2013, at 7:29 PM, Bob Stewart <b...@evoria.net> wrote: > Hi Bob, > > Thanks Bob. It's hard to say whether or not it attenuates at the lower > elevations, but it does add gain to the higher ones. Well, at least I have > some idea what I'm shooting for. > > Bob > > > > > >> ________________________________ >> From: Bob Camp <li...@rtty.us> >> To: Discussion of precise time and frequency measurement >> <time-nuts@febo.com> >> Sent: Thursday, October 10, 2013 4:41 PM >> Subject: Re: [time-nuts] Choke Ring Antenna - Patch Placement? >> >> >> Hi >> >> You are looking for total rejection of any signal below the horizon, and >> near total rejection of any signal within 10 degrees of the horizon. >> Obviously total and near total could have db numbers associated with them, >> but the numbers you get are what ever you get…. >> >> Bob >> >> On Oct 10, 2013, at 2:15 PM, Bob Stewart <b...@evoria.net> wrote: >> >>> I bought a set of Wilton "tuned" pie pans yesterday to experiment with a >>> choke ring antenna. The "kit" consists of 4 pans of diameters 12", 10", >>> 8", and 6". The height of the sides is more or less 51mm. I've been >>> experimenting with placement of the patch in the pit, but I don't know what >>> I'm looking for, so a little help would be appreciated. Am I looking for >>> best overall signal level from horizon to azimuth, or something else? I'm >>> not sure I would know how to measure multi-path levels. There seems to be >>> a definite difference depending on whether the patch is at the bottom, >>> somewhere in the middle, level with the rim of the pans, or even perched on >>> a DVD disk which is level with the rim. I don't have any sort of metal >>> container to use as a support for the patch at this point. >>> >>> Bob - AE6RV >>> _______________________________________________ >>> 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. _______________________________________________ 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.
