Ku-band experiments
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So i've got this old directtv dish, I don't even remember where I
got it from, but over the years I've been repurposing it for various
random radio projects. So I figured it was about time I use it for
it's intended purpose, and try and get some Ku-band reception out of
it.
I had picked up one of those Bullseye LNB's from rtl-sdr a while
ago. I've got another 'universal' LNB for regular tv stuff which is
quite similar, but this one has a slighty wider range.
Unfortunately I'm not within the footprint of QO-100, but I should
be able to receive... other stuff! So I did!
The trickiest thing was getting the thing into the focal point of
the dish. I had previously tried sticking little mirrors on the dish
and what not, to figure that out, but those have long fallen off,
and I didn't have any on hand, so i just kind of watched the signal
as I positioned the thing, and stuck it wherever the noise floor was
highest.
I pointed the thing out the window and started hunting for signals
at where I thought there ought to be satellites. I eventually ended
up mounting the thing on a (music) tripod so I could have more
accurate aiming. Turns out this is kinda needed, because if you're
off even a tiny bit, the signal goes away.
(IMG) The dish mounted on the tripod pointing out the window.
I also learned that glass completely blocks the signal for me :)
So I had to keep the window open whilst it was snowing outside,
but hey! Anything for some radio fun!
In the end I did get a (weak) signal, i'd probably have better
results moving the dish out into the yard a ways, to get it away
from other noise sources.
(IMG) The received signal
I also learned that pointig the thing at my computer shows a lot of
noise. That's usually to be expected with radio things, but I didn't
quite expect to see it in the GHz' ranges. But I suppose it makes
sense. I actually used that phenomenon as a signal source for getting
my lnb in the focal point better.
I also noticed while closing the window, at a certain angle,
the glass would actually reflect the noise from the computer. Neat!
:)