The 1/4 wave of 1.5 GHz is about 5 centimeters. I would expose that much of the center conductor and then angle the shield wires (also 5 centimeters) down at 45 degrees into a cone which will be 135 degrees from the center conductor. Use a very short feedline and use it outdoors. It will not be pretty or high performance but it will be cheap in money and time and may restore sanity.
On Sat, 7 Jan 2012 11:25:19 -0600, "Don Lewis" <dlewis6...@austin.rr.com> wrote: >How long a wire? >-----Original Message----- >From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On >Behalf Of David >Sent: Saturday, January 07, 2012 11:17 AM >To: Discussion of precise time and frequency measurement >Subject: Re: [time-nuts] Getting my Rockwell D200 GPS to work > >I am not suggesting this as a replacement for a proper GPS antenna. I >am suggesting it as a inexpensive sanity check. The loss from >receiving a circularly polarized signal with a linearly polarized >antenna (or the reverse) is 3db. > >On Sat, 7 Jan 2012 17:29:54 +0100, Azelio Boriani ><azelio.bori...@screen.it> wrote: > >>Just take care that GPS signal is right-hand circularly polarized. For >>those interested in building GPS antennae I recommend the QFH-type antenna: >>quite complex but it is the same antenna actually used to transmit from the >>birds. >> >>On Sat, Jan 7, 2012 at 5:02 PM, David <davidwh...@gmail.com> wrote: >> >>> I have done the same thing with an amplified patch antenna facing out >>> the window. >>> >>> I wonder in this case if making a rough 1/4 wave antenna out of a very >>> short feedline would be enough for a cheap outdoor sanity check. >>> >>> On Sat, 7 Jan 2012 14:21:09 +0000, shali...@gmail.com wrote: >>> >>> >I test all my GPS receivers with a hockey puck type antenna attached to >>> the wall in my hamshack, which is upstairs, but under the ceiling and the >>> roof and I have never had one fail to lock within reasonable time. With >>> this setup, Thunderbolts occasionally go on holdover, but never for very >>> long. >>> > >>> >Of course, when I plug them in the external Symmetricom antenna, they >>> typically see more satellites and don't go into holdover. >>> > >>> >I am in Northwest Florida, so probably at a lower latitude than most of >>> you, so the same setup farther north may not work as well. _______________________________________________ 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.