Tuesday, 6 November 2012

KBC: 9450 khz and special test of a digital text....

The Mighty KBC will test to the USA on Sunday 11 November 2012 00.00 -
02.00 UTC on 9450 kHz!

Please join the Mighty KBC for a test of a digital text sent via a
shortwave broadcast transmitter. This will take place during the next
transmission to North America, Sunday 0000-0200 UTC, at approximately
0130 and just before the end of the broadcast at 0200.

All you need is a basic shortwave receiver (no SSB mode is necessary),
and a basic personal computer. Using a patch cord, you will feed the
audio out of the earphone jack (or line out) of your radio into the
microphone jack of your PC. If you don't have a patch cord, you can
try placing the speaker of your radio close to the built-in microphone
of a laptop PC.

You will also need software. There are several freeware or shareware
programs used by the amateur radio community that decode digital text
modes. One is FLDIGI, available from http://www.w1hkj.com .

After installing FLDIGI, pull down the Configure menu, then click
Sound Card, and select the soundcard your PC is using.

You might also have to adjust your audio settings. In Windows 7, left
click twice on the speaker icon in the lower right of PC display, then
click Options, then click Properties, then click Recording, then click
the input that works. Other operating systems will have different
procedures. A good way to test your audio settings is to try to decode
the radio amateurs using the PSK31 mode on 14070 kHz.

For the test digital text transmissions on Sunday, The Mighty KBC will
be using the QPSK125 mode. On your software, your cursor should be
centered on 1500 Hertz, where you will see the "waterfall" of the
QPSK125 signal. You can decode the transmission while you receive it,
or record the transmission and decode from the recording. The latter
will give you more opportunities to perfect the technique.

The test to be transmitted will be a formatted html file. Copy it from
<html> to (and including) </html>, and paste it to a text editor (such
as Notepad in Windows). Save the file, using any file name, with the
suffix .htm or .html. Then open the file in any web browser. If all
goes well, this might be the first time you receive a shortwave radio
broadcast in color!

In the future, an app will be developed to make this process simpler!

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