THE REASON OF AN IMPORTANT STRATEGICAL CHOICE
THE REASON OF AN
IMPORTANT STRATEGICAL CHOICE
While I am
fond for the excellence of the measuring systems , after long thinking,
I have recently decided to push on the use of some and cheap tools as an
alternative way to make our daily work .
What
changed my idea was mainly some things :
- Covid
limitation to bring big strange tools , like intruments on airplanes
- Starting
to give some intermediate tools to people that doesn’t have any professional
instruments
- Advantage
that they can start practically to play with something that we teach on our training at a very low
cost
Nevertheless
, I have to stress that this is only an intermediate step to professional
instruments that luckily in this year cost one tens of the same instruments of
let’s say 10 years ago and have same or better performances .
There are
NO MIRACLES : performances are always
related to costs .
But at the
end I have decided to put together small boxes that , with a PC that you own ,and
you always have to bring with you and you are allowed to bring on an airplane , could help in many cases .
The first
small box is a so called RTL USB KEY ( or DONGLE ) .
It is a
very small SDR ( Software Defined Radio ) , that connected to a PC trough an USB 2.0 ( or higher ) port
,and software can allow spectral analysis , demodulation and other measurements
from 25 to 1760 MHz .
In this
respect I have produced already some video showing how we can point for
instance our satellite dishes , or check on air the FM band or a signal from an
STL .
The
software HDSDR that I have choose for this purpose can be downloaded from here
:
The
ExtIO.dll file to use the RTL Dongle , by put it into del HDSDR folder can be
downloaded here :
http://hdsdr.de/download/ExtIO/ExtIO_RTL2832.dll
Here you
have the links :
|
Pointing a satellite dish with the use of an RTL USB key with the software HDSDR |
|
|
Using an RTL USB Key in the FM BAND with the software HDSDR |
|
|
RTL SDR USB KEY FOR SAT BEACON MEASUREMENTS with the
software HDSDR |
Of course
there are big limitations due to the Range of Visualization that an RTL KEY ( that works with 8 bit ) can
handle ( around 40dB) respect a professional
Spectrum Analyzer ( 100dB) and also the RTL KEY receive spurious signals
and images .
See for
instance signals displayed with a range
of 100dB and the range of 40 dB in evidence .
The reason
why 8 bit correspond to around 40dB can
be found here :
where this
picture was extracted :
Claudio Re
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