After my dad died I got heavy into tropical fish and shortwave listening. I bought an Icom R71a and I got into all kinds of decoders. I built several TV decoders. Now I started decoding those funny Shortwave noises. I built a CW decoder and I bought a Kantronics TTY/Amtor/cw decoder at a flea market. A few months later I bought an old Robot slow scan TV decoder. I changed the capacitors in the scan circuit so I could get part of Weather Fax pictures and maps.
I was selling and buying stuff at the annual Gilfer Radio flea market in Park Ridge NJ. After it was over I helped Jean the owner of Gilfer clean up. She gave me a stack of CQ and other Ham magazines. When I got them home I realized they were a collection of magazines that all had Radio Fax projects in them. I read all the articles several times over.
At that same time at work we had a problem with paper tape readers. The guy on the job did not understand what stepper motors were or how they worked. I solved the problems and started collecting stepper motors and circuits. At some point I realized I could turn a drum once, twice or four times a second with perfect accuracy.
I got the Drum spinning and the signal decoded. I tried a thermal print head and paper with no luck. In one of the magazines they mention old style Fax paper. 20-30 volts causes the paper to discolor and or burn. The paper is for a Xerox Telecopier. I called Xerox and the girl said it was $80 per box. I told her it was for a hobby. She switched me to a guy that asked me alot of questions. He was amazed how far I got. I told him I was using floppy stepping motors to turn my drum and one to move the head. He then started telling me about their color unit. He took my name and address and I received some free sheets of FAX paper. The paper produces smoke as it prints. The paper goes under a strip of aluminum foil. That is wired to the axel of the drum. The paper is held on with a spring. Not Shown. The needle is one bristle off a wire wheel. The head is pulled down to the paper using a magnet.
I got the unit working big time!!! I picked up Newspaper Photos that were sent from South America to cruise ships. They send the picture several times. They send different colors to make up the front page. The story went via TTY. I picked up Russian and Korean ships at sea news letters. I tracked a hurricane from the gulf to my house. I redid the decoder real quick and got a Goes Satellite picture as it went over my house. The picture had a Doppler curve because my drum speed was constant. The real machine tracked a tone and devided that to set drum speed. The unit hooked to a Sony 2010 produced a weather map at Gilfer Shortwave. At a Super Bowl party it was the half time show. I stung a wire outside at a friends and using my R71a I got a perfect weather map.
I joined a BBS systen in Texas. I got FaxDal software. I then started building a plug in computer board. See Pic The board has a 565 Phase Lock Loop chip, two opamps which make a audio filter and an A to D chip. All mounted on a serial card. The signals go into where the Uart was. 8 bits of analog data. This idea became QADDI my first published article. Quick and Dirty Data Interface! My articles showed how to measure Voltage and Temperture using my QADDI method. The crazyness paid off! It was just the beginning!!!
Radio Fax PC Board from Serial Card
Email: John a quick question
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