[aprssig] Dayton meltdown.

Robert Bruninga bruninga at usna.edu
Mon May 23 18:53:35 EDT 2005

But remember that if it is passive, the maximum
signal is only what can be received by the one
yagi.   Compare this to ALL the energy hitting
the mountain ridge along several miles of ridge.
Even if the knife-edge refraction is only one
thousandth of what a yagi can do, you have
10,000 times more surface area doing it... Bob

>>> k5dtn at swbell.net 5/23/2005 6:07:27 PM >>>
Don't have any personal experience with these, but in
the early days of television, I remember reading
reports about this very technique for getting the TV
signals over a mountain ridge and into the valley
beyond. Just two yagis, one pointed at the TV
transmitter and one pointed down into the valley
needing the signals. Just ordinary feedline between
them - completely passive. 
Supposedly worked pretty well if there was a good
strong signal from the TV at the receiving yagi.

73, Claude Head - K5DTN
--- VE7GDH <ve7gdh at rac.ca> wrote:
> re the suggestion of a passive GPS repeater...
> > Wow.  I learned something new today.  Never heard
> of this before.
> > Interesting.
> I have never tried it, but there could be other
> applications for "passive
> repeaters" where there are (e.g.) a couple of Yagis
> on a mountain-top that
> are tied together with coax and nothing else in
> between... one pointed down
> each side of the mountain.
> I've always assumed that for best results, the
> transmitters down in the 
> valley should use a directional antenna pointed at
> the passive repeater, but 
> has anyone on the list actually tried a passive
> repeater? The re-radiated 
> signals must be pretty low level, but I wonder if
> there are any locations 
> where a couple of Yagis tied together on a hilltop
> would help out  APRS on 
> 144.390 MHz anywhere.
> 73 es cul - Keith VE7GDH
> --
> "I may be lost, but I know exactly where I am!"
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