[time-nuts] GPS antenna??

[Alan Melia]

Hi David yes its ferro-concrete which makes quite a good screen (a lot worse 
than domestic brick) but the windows are not coated I think. (BT Labs at 
Martlesham)

Thanks all for some thought stimulating ideas .....GPSDO outside might not 
be too easy....1U rack case mains powered....no power available outside but 
10MHz (or 5MHz in this case) coupling through wall or window is a lot easier 
if I had a battery powered unit.....I have a feeling there may be battery 
back-up terminals on it must get the book out.

The windows are SW I think but give a good view of a quadrant of the sky. It 
will be interesting to see how long it takes to lock up compared with an 
outside antenna.

Thanks and Best Wishes
Alan
G3NYK



----- Original Message ----- 
From: "David J Taylor" <david-taylor at blueyonder.co.uk>
To: "time-nuts measurement" <time-nuts at febo.com>
Sent: Monday, April 08, 2013 7:46 PM
Subject: Re: [time-nuts] GPS antenna??


> 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
> ===================================
>
> Alan,
>
> Here I am on the top floor of a standard house, and get an adequate signal 
> for today's GPS receivers with simple patch antennas.  One GPS I have is 
> in a walk-in cupboard adjacent to a north-facing outside wall.  Obviously, 
> there are no guarantees, but you may get away with just being adjacent to 
> an outside wall, or getting the puck near the non-opening window (but that 
> may be worse than the wall).
>
> If it /must/ be a GPS relay like you are suggesting, perhaps for multiple 
> receivers inside a room, I can't help.  Be sure to place the puck on an 
> appropriate ground plane - I find a clean, unused baking tray to be 
> perfect!
>
> 73,
> David GM8ARV
> -- 
> SatSignal Software - Quality software written to your requirements
> Web: http://www.satsignal.eu
> Email: david-taylor at blueyonder.co.uk
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