[time-nuts] Best location for a GPS antenna...?

[Tom Knox]

This is a great discussion. I have been trying to decide the best compromise between optimal reception and safety.  Here in Boulder afternoon thunder stormers are often a daily occurrence.
I cannot afford to learn from my mistakes on this one.
Thomas Knox



> Date: Wed, 11 Apr 2012 22:37:06 +0200
> From: attila at kinali.ch
> To: time-nuts at febo.com
> Subject: Re: [time-nuts] Best location for a GPS antenna...?
> 
> On Wed, 11 Apr 2012 22:06:06 +0200
> "Andrea Baldoni" <erm1eaae7 at ermione.com> wrote:
> 
> > On Wed, Apr 11, 2012 at 10:19:40AM -0400, Bob Bownes wrote:
> > 
> > > I do like the optical isolation suggestion. While less than optimal,
> > > perhaps the easiest solution is not to put the isolation between the t'bolt
> > > and the antenna, but to put the isolation between the t'bolt and the
> > > distribution amplifier.
> > 
> > By the way, would it be possible to retransmit the GPS signal to isolate it?
> > 
> > I mean, rx external antenna -> preamp -> tx directional internal antenna -> big
> > air gap -> rx directional internal antenna -> receiver.
> > The preamp would not be so power hungry as the full thunderbolt and maybe
> > it could be powered via a magnetic link (or a little solar panel with a
> > lamp illuminating it).
> 
> Yes it would be. What you basically would need is to have a LNA,
> a bandpass filter and something that converts the voltage into
> light with very little noise. I think it would be easiest to down
> mix it first to 100MHz or so, then modulate a laser diode. In the
> house you'd have to mix it up to 1.5GHz again, of course.
> 
> I have no clue whether that is feasible from the noise this whole
> circuitry will add or whether it would add so much noise that the
> receiver would have no chance...
> 
> 				Attila Kinali
> -- 
> Why does it take years to find the answers to
> the questions one should have asked long ago?
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.