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. | |
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. | |
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! | |
:) | |
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