Magnus Danielson skrev:
b...@lysator.liu.se skrev:
If you are in Scandinavia, the GPS birds will not spend much time (if
any?) to the north of you. Slide 12 of
http://web.ics.purdue.edu/~ecalais/teaching/geodesy/Satellite_orbits.pdf
suggests that the most northerly orbital point is at the latitude of
Denmark.
With a decent antenna siting you see plenty of SVs to the north. Magnus
problem is that there are lots of rather close by trees and stuff. These
trees are also much taller than the antenna position.
Indeed. The southbound sats goes almost over the head, but I also get
long tracking periods for sats way up to the north.
Since the house sits partly in a valey and the neighborhood is rich of
trees there is plenty of foilage. To the north is a building, two
stories high and ground level for it is just above the upper of mine,
which pick up the extreme north direction.
The location also requires an antenna mast forr the TV reception. With
modern digital transmission it is best to have a good margin for
reception, or there is no TV at all.
If I had a flat roof I might just put a ladder up to the antenna, but
unfortunately not so.
Sky-view of GPS antennas was not of concern when picking this house.
Maybe it should be for the next.
To follow up on this... I have now received my LNAs and I have installed
one. The LNA gives me a 16 dB boost, but lack of a bias tee force me to
use a passive splitter to act as the bias tee, and that sets me back 6
dB, so I effectively only gets 10 dB of boost, but the effect is
certainly there, the Z-12 tracks significantly better.
Just goes to show that LNA may come to assistance. Thought this may be
useful to some. A second LNA could boost me up even more, but using a
proper bias tee should give me about 6 dB.
Cheers,
Magnus
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