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G3XHB on CW 

Some notes  from September 17th demo

For cw reception I demonstrated Sergei Podstrigailo (UA9OV)’s decoder program Cwget and coder Cwtype.  These can be downloaded from the website www.dxsoft.com. If your rig is capable of CAT control Omnirig from the same site is one of the better controllers.  All these programs will link to the logging program AAlog to form an integrated package. This is also on the dxsoft website. I do use it but this program is less reliable than others and a little irritating to use as it's prone to locking. 

You will need to arrange an AF feed from the RX to your computer.  This can be as simple as a bit of audio coax from the back of the rig to your computer microphone or line input.  This is often perfectly satisfactory, especially with more expensive rigs which perhaps have better isolation of the external connections.  With more basic rigs you may have to break an earth loop by adding an audio line xformer into the link. One can often be liberated from inside those dial up modems we all used a few years ago and have now been discarded, and such a link worked satisfactorily for me for a while. Alternatively, off the shelf digimode interfaces are available at prices from £50 to several hundred pounds. These also provide the reverse audio path for transmitting the digital signals required by modes such as PSK, JT65, FSK442 and WSPR, but for cw it is better to key the TX directly through the key socket.  A good way to do this is K1ELs Winkeyer or similar.  The rig I demonstrated used an interface and a winkeyer  emulator, both by ZLP Electronics (www.G4ZLP.co.uk). These I acquired for a few tens of pounds each on ebay, though you have to wait months for them to come on the market.

If you do have a proper interface or TNC that allows the transmit path too, you can then try digimodes as well.  The most popular are RTTY and PSK.  I did try RTTY in the early seventies using an actual teleprinter and have made one or two QSOs last year using digital software but didn’t find it very rewarding. Similarly I never really took to PSK even though I used it most of last winter. For these I used fldigi, which incidentally also has a cw decoder built in. You can find and download it free from www.w1hkj.com.

Finally we come to Joe Taylor, K1JT and ultra weak signal modes. A good place to start is the website http://physics.princeton.edu/pulsar/K1JT/.  Joe has developed a whole range of modes dedicated to extracting information from very weak signals. The two most used are JT65, which I demonstrated, and WSPR, which I didn’t.  With JT65 you can make a reliable, if formulaic, QSO out of the merest whiff of a signal. WSPR is a weak signal beacon mode. You have to have a live internet connection, you leave the system running for hours, unattended if you wish.  After a period, as long or as short as you like, you go the wsprnet website, enter your callsign and it will display a map of the world with all the stations that have heard your transmissions. Because of the extreme weak signal performance of the mode it’s usually is all over the world. It’s fun, for a few days anyway!

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