[time-nuts] GPS antenna??
Grant Hodgson
grant at ghengineering.co.uk
Tue Apr 9 08:27:38 UTC 2013
Alan
As has already been stated by others, if the purpose of the GPS signal
is for a GPSDO, then putting an active patch next to a SW facing
window should work fine. No need to re-radiate. You only need to
receive 1 satellite in order to get a timing signal - more satellites
will give better (lower) jitter/ADEV, but if you just want an accurate
frequency source for a counter or signal generator then the setup you
describe should be fine.
If that's the case, then it might be worth taking a Rubidium source as
a higher-performance back-up than the GPSDO in holdover, although some
GPSDOs are more equal than others in holdover performance.
regards
Grant
Quoting time-nuts-request at febo.com:
>
> Hi all an interesting problem you may have encountered, I want to use a GPS
> frequency standard inside a building with no opening windows (opening
> windows are known as air conditioning in the UK :-)) )
> This is part of a two day amateur microwave conference so we should have the
> expertise.
>
> I intend to try and pass the signal through a a double glazed glass window
> unit (hopefully not metalised) using a couple of patch antennas. The outer
> GPS antenna is active so will need a 5v supply via an inserter. Inner patch
> active, outer patch passive to avoid problems of feedback. Main antenna can
> be shielded from the "coupling" either physically or with a slab of
> absorber.
>
> Has anyone tried this?.... does it work?.....any gotchas?
>
> Thanks
> Alan
> G3NYK
>
>
>
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