Welcome to: Regulation Nation
-John ============== > Hi > > Flag poles are prohibited. > > Bob > > -----Original Message----- > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On > Behalf Of Randy D. Hunt > Sent: Thursday, September 27, 2012 10:24 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] BPSK Receiver & GPS Antenna siting > > On 9/27/2012 4:20 PM, Bob Camp wrote: >> Hi >> >> At least in my back yard, a 6' tall tripod would be very noticeable from >> a > number of directions. There are many others in similar situations. If I > were > to interpret the restrictions literally as written, an antenna that was > inside the house, but visible through an open window is also a violation. >> >> Bob >> >> >> On Sep 27, 2012, at 7:11 PM, johncr...@aol.com wrote: >> >>> Various comments - >>> >>> Hal mentioned SNR for the scheme I suggested. A PLL can be a coherent > demodulator of arbitrary >>> bandwidth. Thus the PLL at the output of the doubler can have a small > bandwidth since at that point >>> there is no PSK, it having been removed by the doubler. So given a >>> stable > VCXO you can probably get down >>> to 1 Hz and thereby achieve a good SNR. There is a lot of stuff out >>> there > on phase tracking receivers >>> that do exactly that. You know the frequency so the loop does not have >>> to > search far and the BW can be increased >>> for acquisition and closed up for tracking. >>> >>> On writing reams of code - my point was that it is not required to used > the admittedly more powerful software >>> techniques to do this job - I noted that one reason to write reams of > code is for the fun of it, this is after all >>> a hobby. >>> >>> GPS Antenna Siting - >>> >>> Lets not make this so hard. Mine is at 6 ft elevation and is blocked to > an elevation angle of 20 to 30 degrees by a house >>> within 15 ft and a forest of trees. I have room and no restrictions but >>> I > also have severe thunderstorms - so the house >>> plays lightning protect for the antenna. My T bolt tracks a Rb to >>> better > than 1e-12 over 24 hours with no serious 10 MHz phase bumps >>> as plotted on a strip chart recorder. >>> >>> Sooooo - >>> >>> Put your antenna at 6 ft in back yard. Start out on a photo tripod - >>> who > is gonna notice? >>> set up a t bolt at EL=5 AMU=0 Damping = 1.2 and Time Constant = 100 >>> sec. >>> get the t bolt manual >>> get Tbolt monitor >>> get Lady Heather and read all that stuff. >>> >>> Run Lady Heather antenna survey (command SAS) for at least two days - > you get a map of signal level in dBc vs elevation >>> Reset the Tbolt elevation mask to reject anything that is shown as > blocked using the signal >>> level map. Likewise experiment with the AMU setting to reject the weak >>> = > poor signals. Mine works good >>> with AMU all the way up to 10 as fewer good satellites are better than > lots of weak ones. >>> >>> The satellites are in high orbits so masking those below 25 degrees is >>> OK > and the AMU sets the acceptable signal >>> level - at AMU 10 my setup throws out those below about 40 dBc - the > strong guys go up to 50. This is a function >>> of you antenna performance so some experimentation is required. >>> >>> -73 john k6iql >>> >>> >>> >>> >>> _______________________________________________ >>> 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. >> > Put up a flagpole. > > Randy, KI6WAS > > _______________________________________________ > 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.