> Tom, > > John A and I had a short antenna email earlier today, mostly about the fact > that both of the GPS antennas we were using died. > > I asked a question about certain "commercial" antennas which included the > Timing 2000, HP 58532A and the Datum 2640NW/DE, as to wether there were any > opinions as to which is the better timing antenna. Neither of us has much > of an idea, do you have any thoughts? > > Had
I've heard that many modern telecom GPS timing antennas are heavily filtered since they are usually placed in high RFI locations. This may be good for them but I think it has negative side effects for the kind of precise timing we do, so I'm told. I'm going to ask Dr Clark to handle this one as he understands GPS antennas very well. TAC -- what I'd like to know is if patch is better than helix, if filtered is better than unfiltered, how much amplification is too much, vintage 1990's era antennas vs. 2005 antennas, real splitters vs. Radio Shack splitters, antenna or preamp tempco issues, cable loss and impedance issues, etc. At what ns level does a groundplane start to matter. I guess what we need is some kind of Time Nuts guide to surplus GPS antennas. If it's not possible to give a black and white answer to what kind of antenna is best for a Z3801A-style GPSDO, then at least, what are the factors that make one better than another. And is any of this simple to determine with experimentation? Maybe we can all chip in and test a dozen antenna types to find the answer or to confirm a prediction. /tvb _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
