Saturday, April 14, 2012

HF Digital Modes: JT65

An article in the May 2012 QST (page 44) highlights JT65, an HF digital mode that is seeing strong growth. Its main appeal seems to be that it enables contacts at very low signal levels (using low transmit power and simple antennas). This is a result of its being developed for meteor scatter and EME communication. The digital protocol and software were developed by Nobel laureate Joe Taylor K1JT whose web site devoted to weak signal communication provides background.

A while back Jorge NN4QQ made us aware of WSJT software being used to test propagation paths (Weak Signal Propagation Reporter) and to populate a database and map - WSPRnet - that is available for viewing by anyone on the Web.

A special HF Digital page from ARRL provides links to information, software downloads and audio samples for JT65 and several other digital modes, including the ever popular PSK31.

A Windows version of the JT65 software was developed by Joe Large W6CQZ and is available at the HF Digital page. A brief web search shows that Mac users are also running JT65 via two options:
  • Compiling WSJT software to run on a Mac
  • Running the Windows version under WINE or Crossover
For details see this Google Groups posting or this Yahoo Groups posting. Many other applicable results can be found by searching with "JT65 Mac". Of course, Linux can also run this software.

Wednesday, April 4, 2012

Special Event Stations: 100 years since Titanic sinking

Many special event stations this month are observing the 100th year since the sinking of the Titanic (14 April 1912), commemorating the role of radio in reporting the event and summoning of help. Here are a few of the web sites that provide information, including dates, times, frequencies:
 On a related note, the article The Titanic's Role in Radio Reform tells how the Titanic sinking triggered a century of radio improvements. A sliding timeline brings a series of 29 short stories or profiles of events and developments.