Thursday 7 January 2021

Built a paddle key!

 Looking on Thingiverse 3D printing web site where people post hundreds of STL files for download and 3D printing I found a morse code paddle key. My son has a couple of 3~D printers so I persuaded him to download it and print it.

So here is my new set up, on the left a very low cost Chinese Switch Mode Power Supply (how can you get 5A/12V from such a small device? Incredible these SM PSU! But very very RF noisy!), centre is my just completed QCX+ transceiver (40m version) and to the right my 3D printed paddle. Don't like the colour much but that's the "inks" my son had threaded in his printers...

PSU, QCX, Paddle

Now the real challenge - to learn morse code and learn to use this paddle.

1 comment:

Ones and Zeros on the Interweb said...

Just on the point about your use of a cheap switch mode power supply... Bad bad idea. I just made up a QCX that a friend offered me just before Christmas. He had bought it a couple of years ago and never built it up. I put the radio together and went through my filing cabinet drawer of random old wall warts and redundant switching power supplies from retired netbooks and laptops. and I settled on a neat looking 12v, 3 amp Asus power supply. Of course it worked fine, but I was struggling to hear qrp stations that replied to me on 7030khz. I was getting 569 from them and could barely hear them. They were lost in of noise. Big stations came banging through clear as a bell, but stations like my own were drowned by switcher noise. Today I put a linear supply on the radio and was astonished at how quiet from the noise point of view the band was. I could suddenly hear lots more stations that would previously have gone unheard.

Of course I knew about this issue, but when I ran the old laptop supply with a dummy load on the BNC output, I could hear none of the noise. It only became apparent when I connected the antenna, so I had mistakenly assumed the power supply was acceptable and the noise was just band noise or an artefact of the receiver design. Not so at all.