The principle of forward error correction

Paul Nicholson wrote an excellent article explaining the fundamental principle behind forward error correction codes.
It does not discuss any particular coding scheme (Convolutional, Reed-Solomon, LDPC, and so on), rather, the intent is to home in on the underlying principle that all forward error correction schemes exploit. This is done so without using any mathematics at all, well perhaps just a little simple arithmetic.

Read the article.

Australia - Canada QSO on 630 meter

On September15th Roger, VK4YB, and Steve, VE7SL, successfully completed a two-way JT9 QSO after a few previous attempts. With a distance of 11802 km, this QSO is believed to be the longest two-way QSO ever completed under amateur service rules on 630 meter.

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IARU Regon I Interim Meeting 2016

At the IARU Region 1 Interim Meeting (Vienna, 16-17 April 2016) the Norwegian society NRRL introduced a proposal to introduce a beacon segment from 476 - 477 kHz.

This proposal was declined by a vast majority.

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Propagation page

Alan, G3NYK, did write a great article on medium wave propagation that I proudly added to the 472kHz.org website.

Have a look at it!