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03/14/2007 Entry: "GPS antenna system total delay"

Having done all the measurements shown in the previous entries, the total delay of the GPS antenna system should be:

LMR -400 antenna feedline to 2-port splitter: 56.06 ns
2 port splitter: 23 ns
LMR-400 jumper from 2-port splitter to 8 port splitter: 9.4 ns
8 port splitter: 15 ns
10 foot LMR-240 jumper from splitter to receiver: 12.55 nanoseconds.

Total: 116.01 ns.

This doesn't include any delay due to filtering in the antenna itself. The Motorola 2000 Timing antenna has a dual filter. It's only an assumption, but if the filter elements are similar to those in the GPS splitters, we can assume 15 to 25 nanoseconds of delay in each stage. Again, this is only a guess at this point, but I am adding ~30 nanoseconds to compensate for this, and forgetting about any precision past a few nanoseconds!

So, the "antenna delay" value I enter into the GPS receivers will be 145 nanoseconds.