ARLA/CLUSTER: Você sabe que pode escutar as bandas de amador com um simples "dongle" ligado a uma porta USB do computador.?

[João Costa > CT1FBF]

Ham Radio and the RTL SDR Receiver

Did you know that you can listen to Ham Radio via a simple dongle
plugged into your computers USB drive?
The device is called a R.T.L.-S.D.R. receiver, it uses software which
allows you to listen to Ham Radio and many other radio transmissions
including Police, Fire and Ambulance transmissions. The receiver is
based on the R.T.L.2832-U chip-set and often called the D.V.B.-T TV
tuner

These cheap dongle receivers cost as little as 8 pounds and turn your
computer into a general coverage receiver. With appropriate software
you can store and scan frequencies just like scanners costing many
hundreds of pounds

Software defined dongle receivers on the market including the Air spy
and S.D.R.-PLAY costing around $199 and £149 respectively and there
are other higher priced units including the Hack-RF costing $300 and
the Blade-RF which currently sells for $650 these units actually
transmit as well as receive.

Software defined radio receivers replace traditional radio receivers,
which were constructed with radio components including modulators and
amplifiers, these hardware components are now replaced with software.
Modern computers using easy to download and install programs do the
work of all the processing needed to de-modulate signals and turn your
computer into a modern radio receiver.

S.D.R. radio offers the opportunity to de-modulate ham radio
transmissions across a wide part of the radio spectrum. High frequency
bands are covered and you have the benefit of listening to a full
range of transmission modes including single side-band, amplitude
modulation, and constant wave or C.W. many allow F.M. reception too.

S.D.R. radio allows hobbyists to monitor aircraft control
conversations on both short wave and V.H.F. band. You can also track
aircraft using ADS-B (Automatic Dependent Surveillance-Broadcast)
which plots the aircraft position on a local map. A.C.A.R.S. is also
catered for making S.D.R. receivers a very beneficial tool for the ham
radio hobbyist.

Programs are available which allow the reception of digital radio
mono-dial this form of broadcasting is used by international broadcast
stations, It provides superior audio quality compared to A.M. signals
by utilising digital audio encoding.

One of the most interesting applications to use with your S.D.R. radio
is receiving N.O.A.A. weather pictures, there are many multiple
satellites passes every day, N.O.A.A. weather satellites broadcast
Automatic Picture transmissions and these broadcasts contain live
weather images of your area.

You can de-modulate N.O.A.A. pictures with a good outside aerial and a
program called S.D.R.-Sharp and an additional decoding program, these
images can be seen several times a day.

There are many more programs to use with S.D.R. radio, D-star and
D.M.R. together with fusion transmissions can be de-modulated. A great
benefit you have using these simple radio receivers is that most of
the programs are completely free to download and use.

By
John Allsopp G4YDM
https://g4ydm.blogspot.co.uk/

Article Source:
http://EzineArticles.com/expert/John_Allsopp/1925417

Article Source:
http://EzineArticles.com/9621573