Hi Flag poles are prohibited.
Bob -----Original Message----- From: [email protected] [mailto:[email protected]] 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, [email protected] 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 -- [email protected] >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > > _______________________________________________ > time-nuts mailing list -- [email protected] > 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 -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
