[time-nuts] Choke Ring Design for L1

[Bob Camp]

Hi

That's one of the many things that makes this all a bit tough to work out. 

Even without a choke ring, a pie plate, or a ground sheet involved you can move a cheap GPS timing antenna 5 feet and see a very real change in plots. Up / down / left / right often the move does not make much sense. I suspect that if the antenna was 500 feet above all local obstructions that would not be true. In more typical "home user" settings it certainly can be. 

Plotting software has been around for a *long* time......

Bob


On Mar 14, 2010, at 5:59 AM, Peter Vince wrote:

> As I understand it, the GPS signals are circularly polarised, and so
> surely reflections will reverse the sense of that polarisation such
> that the antenna will be insensitive to them?  Maybe Warren's simple
> pie dish is working by shielding the antenna from the true MULTI-path
> reflections, and any direct SINGLE reflections it produces are ignored
> due to the polarisation reversal?
> 
>     Peter
> 
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