Mr. Juliusz, father of Mr. Jarek, writes:
For almost 20 years, this key was used to maintain sea-land communication in maritime radiocommunication and sailed with me, controlling MEWA, MARCONI MARINE, JVC, ELECTROMEKANO, MITSUBISHI ELECTRIC radio stations, withstanding storms and hurricanes in the Baltic Sea, North Sea, Atlantic Ocean The Indian Ocean and Pacific, perfectly working in all climatic zones of the world. He could not stand the experiment of my young child, the future electronic, who, after returning from the cruise, connected him at home to the Polish 220V 50 Hz network. Since retirement, I was no longer interested in restoring this key to work, but my adult son, after many, many years, took pity on him and corrected his youthful error. The key is working again!
Mr. Jarek, son of Mr. Juliusz, adds:
The key is my father’s property and it was built by him in the 80’s. He used it on ships, where he worked as a radio officer. The story is interesting that after one cruise, as soon as he came back home, as a teenager, I connected this 24 V key ended with a regular plug to a wall outlet. I only remember that something shot at him, smoke flew out of him and the key landed in a drawer for years. When I last found him, I decided to rebuild him. However, my dad did not remember on what schematic diagram it wad done, and in addition all the IC from the sockets were removed and the capacitors were soldered out. The only mention was – that the IC are popular UCY’ki.
After a few hours of digging the Internet and comparing various schemes from those years to the paths on the printed circuit board – Eureka, I found a matching SP5DDF key in the Polish journal “Radioamator i Krotkofalowiec” No. 1’76. After completing the elements and replaceing the power supply to the stabilizer 7805, the key started working, thanks to which Dad was very happy.
I would like to add that I was amazed with the technique of creating a PCB for this key – the path fields were cut by hand with a stylus, which is why they create a mosaic of rectangles. Today, in the era of CNC, paint for spray painting or ordinary thermal transfer is a rare relic of those years.
I will add as a curiosity that I made one copy of this key for myself. I made a plate in “Eagle” following the one from the newspaper. The key, of course, works and waits for the manipulator to be made and at the end of my learning of the Morse code.
Regards – Jarek Pick