Interface to the transceiver and go CW

Connecting the transceiver to the computer was not easy, the transceiver has a USB interface but this is good for changing frequencies and settings, but not what I wanted. The microkeyer II (MK2) in the image below on top of the Yaesu does bring you somewhat further. That green wire below the power button on the FT-991 connects the microkeyer II to the CW key jack on the transceiver. The MK2 connects with one USB cable to the PC and I use a separate audio cable from the Yaesu to the PC sound card. Remove the Yaesu USB cable when you do that because it generates conflicts with the autotuner which is also on the CAT interface. The audio cable to the soundcard allows one to generate waterfall plots on the PC and to isolate that part of the spectrum that is the CW code.



To test the transceiver CW capabilities you are best off with a manual keyer. I retrieved my 45 year old keyer which I got as a 12 year old to practice morse code with one of the kids on the block. There is a keyer program in the Yaesu transceiver which is for these fancy double action keyers, but I had to turn that option off. Finally the Yaesu did produce CW code, option break-in has to be on, option keyer has to be off and it is only going to work when you put the transceiver in LSB-CW or USB-CW mode. No CW keying in USB LSB FM or other modes, sure, why should you?


My CW keying practice is somewhat shady, I can read CW but that is about it, transmitting CW  is even worse. Perhaps I could come to the point of reading and sending 10 words per minute, but it is far easier to tell your PC to do the work. Most CW you hear nowadays is made by the computer I thought until PA4M reminded me that this is not necessarily the case. Trained CW operators don’t use a PC, but are armed with handkey, paddle, bug or sideswipers. They all come with a distinct sound and the trained ear will recognize this according to PA4M. It is on my list, I will try to recognize it.

The speed of CW code varies between 15 and 40 words (like PARIS) per minute, and when the signal to noise ratio is not too bad your CW software (I used CWget among others) simply decodes it. Transmitting CW is more difficult, the USB router software that comes with MK2 needs to assign a COM port for winkey, most software does not use winkey and attempts to directly cast audio into the transceiver. Sending audio from the PC to the transceiver is something that I never got to work, maybe I will at some time, but so far winkey does the job.

The reverse beacon lookup map that I found via the dxwatch website was sort of a surprise to me, it shows where my CW’ing was heard on 20m. May I now legally brag that my keying was heard across the Atlantic?


The reason that CW is so efficient is that all the transmitted energy is compressed in a very narrow part of the spectrum, probably less than 400 Hz, so that the spectral density is large, I guess it to be 10 or more times as dense as SSB with a bandwidth of 3 kHz. Narrow FM at 12 kHz used by radio amateurs is even worse, broadcast FM is more like 200 kHz bandwidth because of different frequency deviation. It is the spectral density that makes CW so impressive. This week ionospheric propagation conditions were insufficient to cross the Atlantic with SSB, “you hear them talking in New York but never say something back (no pun)”.  Apparently with all means at my disposal the computer generated CW did make it across the Atlantic, I was impressed.

April 25th is Marconi day, born in 1874 he was the first to send a wireless message over sea in 1897. In 1901 he was able to transmit the first radio message across the Atlantic, it was a remarkable invention that changed the world. [link]

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