Hi, On 05/24/2018 10:41 AM, Clay Autery wrote: > Putting in a hardware order... > > Question: Is it recommended to put terminators on all unused GPS Distro > amp ports? Output ports on GPSDO and NTP servers (10MHz and PPS). > > Thanks! >
All GPS splittes I have looked at so far uses the Wilkinson power-splitter. It provides some isolations between the output ports, or rather, the ideal scenario has perfect isolation, the real world not so much naturally. If you consider a two-port splitter where you leave one end open, and ignoring the fact that the splitter math actually wants a 50 ohm load to perform correctly, there will be some leakage over to the next port and full leakage back to the source. Usually we can assume that the source direction wave gets dampen in the amplifier sitting there to compensate gain or for a passive one dampens in the cable back and forth as well as not getting a perfect reflection in the antenna source impedance. The direct leakage to the next port is likely to dominate. Regardless, this will behave as multipath for the GPS signal and just contribute to the multipath environment that the antenna already have. It's only when you have a really crap splitter that you need to be careful. For carrier phase measurements, you need to be more careful about signals, but mostly for stability of signals. So, for most cases, I don't bother on my splitters. I would only care if I would really try to get stable and accurate measures, but not because it would have much of an impact, but just because I don't want a simple to fix thing do me any harm. Cheers, Magnus _______________________________________________ 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.