I live in a depression pretty much surrounded by old oaks. I have SatStat set to ignore anything below 30 degrees. Receivers are HP Z3801A's with HP antennas 4 feet apart on one mast that takes them to the roof line. Both see the same sat's but with different levels in the hundreds. Lowest number is two, highest six.
I have two Racal 1992's operating. I use them in Phase A-B mode, with one receiver to A and the other to B. The drift rate is slow, but they do drift. I don't remember if there's a net drift, because I used them against cesium and rubidium standards where there was a net drift, a few years ago. I suspect that your problem has to do with the way you are driving the external standard input on the 1992. Try eliminating that problem by using the internal standard and setting the function to Phase A-B. You should see a number between 0 and 359 that has maybe 5 counts of noise, but changes over hours, on the average. Tell us what you see when you compare two receivers and pairs of receiver and standard. Be sure that the 50 ohm terminator light is lit on the 1992 for inputs A and B. If the numbers are unreasonable, tell us about the settings of your 1992 input options. Bill Hawkins -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jim Robbins Sent: Monday, June 09, 2008 6:30 PM To: [email protected] Subject: Re: [time-nuts] Measurement of Rubidiums Hi all, Well, I have good news and bad news. The good news is that I believe I now know why I was getting the strange readings on my Racal 1992 with the Thunderbolt GPS and/or the Starloc II and my Rubidiums. Neither GPS receiver was able to lock onto enough satellites (if any). The bad news is that that the failure to lock is due to the location of my home/antenna out in the woods with the HP GPS antenna up about 10 feet above the roof (i.e. 32 feet above ground). I am surrounded by trees in a sort of "race track" shaped clearing, with the short axis closest woods being about 57 feet from the antenna (both East and West sides) and having a height above the antenna height of 38 to 48 feet. The long axis woods is some 75 to 108 feet from the antenna and having a height above the antenna height of between 18 feet (South) and 48 feet (North)! The long and the short of it is that the angle of view of the satellites is seriously blocked and varies from 35 degrees to about 7 degrees in the South! Sorry that my contribution to the group is to reveal that you probably can't use GPS if you live in a hole in the woods! I've played with the geometry and I'd need a very tall tower to get the angles all down to 7 degrees or less. I am discourged, to say the least. Anyone got any other ideas besides going back to Loran? Jim Robbins _______________________________________________ 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.
