There is a growing world-wide interest with digital voice
communications on the HF bands. The D-Star equipped systems have been
testing as has an open source solution FreeDV which uses the Open Source CODEC-2 code.
Digital voice allows SSB quality communications in half the bandwidth and at lower power levels.
The technology is in its infancy but could be the way of
the future for HF communications, as always the amateur radio hobby
forms the best platform for innovation and improvement of new
technologies.
In order to allow more people to hear FreeDV in action
ARNSW (Amateur Radio New South Wales) has kindly allowed the relay of
it's VK2WI transmission, next Sunday, January 6th. (UTC 23:00 - 23:59
5th. January) to be relayed by Ed VK2JI from the
Central Coast using the proposed Digital Voice 40m calling frequency of
7.190MHz LSB. Ed will only be running about 25W into a 40m wire loop
antenna, so low signal strength tests can take place.
It may be that this will be a world first of a national
news bulletin being transmitted using a digital voice mode on the HF
bands.
To be able to receive the transmission you will need a PC
connected to your transceiver in exactly the same way as a connection to
run digital data modes (e.g. PSK31, FSK31, RTTY etc.) and on the PC
(either Windows or Linux), you need to install the FreeDV program (which
is free to download from http://freedv.org where you will also find installation instructions and general information).
If you successfully receive the test transmission or if you
have a general interest in Digital Voice on the HF bands, please post a
message to the digitalvoice (all one word) google group where all
matters FreeDV are discussed.
Tnx & 73
Ed VK2JI
Ed VK2JI
(Source : Southgate Aateur Radio News)
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