I was posted at the same station Chris Spacone described in the Sherlock posting The Case of the Stuttering Tape Drive a couple of years after Chris left. The PDSs (program development stations) for several of the ATE (automatic test equipment) stations had been moved back into the room facing the runway and the surveillance radar site. The new solution had been to cover the windows with aluminum foil to block the high-power radar signals. It was crude but effective.
My first computer was a RS color computer, or COCO, as they were called. The programs were stored on a regular audio cassette tape drive. When I set up my computer and tried to load programs from tape, I would get random I/O errors. If it was a long program, I would not be able to load it. I thought all my program tapes had been damaged in shipping.
That went on for a couple frustrating days. One day, I was listening to the stereo while working on the computer at home. The stereo started to emit a periodic buzzing approximately every 12 seconds. I was trying to load a program. Almost simultaneously the stereo went bzzt, and the computer halted loading for an I/O error.
Eureka! My apartment was on the third floor of the building on the side facing the radar site, which was only a couple of miles away. The period of the dish rotation was approximately 12 seconds. Every time the main beam swung past, the electronics in the apartment went crazy. Touch lamps would turn on or off by themselves. The TV cable box would change channels or turn itself on.
To fix my tape drive, I shielded it with aluminum foil. The noise was reduced, but I still had occasional errors. Within a couple of months, my final solution was to move well away from the radar site. I hate to think of what that RF energy was doing to people who stayed in that building.
The radar also affected the fluorescent tubes we used to test emissions. We used a neon bulb. The bulb would light up in the presence of strong RF signals. You could even set off photo flash bulbs with the radar pulse.
This entry was submitted by Brian Jahraus and edited by Rob Spiegel.
Brian Jahraus joined the Canadian Air Force right out of high school, becoming an Airborne Radar Technician. He served 22 years in the military, including 13 years in Cold Lake, Alberta, where he was born. He is now employed as an instrumentation technologist doing wind tunnel instrumentation support. In addition to his military training, Brian also completed a four-year college diploma in telecommunications technology through part-time studies. He has an interest in computers, both hardware and software, as well as an interest in robotics, astronomy, and vintage motorcycles.
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I'd like to add some to the discussion on the biological effects of RF. 1. Way back in the early '70s I worked at Motorola Comm division; next door to my lab was one run by Dr. Quiriano Balzano. His expertise was (still is, I suppose) exactly that: biological effects of RF radiation. At the time, he was doing extensive research in a very direct way (very un-PC now!). He used lab rabbits, exposed to well-controlled RF fields over a wide range of frequencies VHF upwards) for long periods of time. He found that the most sensitive indication of damage were the rabbits' eyes; they would develop cataracts after a sufficiently long exposure to a sufficiently high field strength. He then measured the near-field strengths and spectra of the many types of hand-held equipment that Motorola manufactured and sold, and conducted a years-long study using several times the highest levels he measured. NONE of the test rabbits ever suffered any ill effects; the resulting paper was published, reviewed, etc. and was generally accepted as valid. No subsequent study has ever been conducted to that same level of detail and thorough ness!
2. There is a very large study group that has been voluntarily exposing themselves to RF field strengrths MUCH MUCH higher for MUCH MUCH longer than, for example cell phones (especially current technologies, which use very low transmitting power even in marginal areas). I refer to the 1 million+ or so radio amateurs (I am a Life Member of both the ARRL and the IEEE) around the world. While I am not aware of any organized scientific study of this group, from my personal observation I imagine hams are on average among the HEALTHIEST and longest-lived populations! I am quite surprised no one has ever thought about doing that study; I suspect that far too many of the possible researchers have axes to grind that might be blunted by its results!
I would imagine there would be some negative impact from all of the RFI. But there doesn't seem to be. Can that just increase year-by-year without it having any impact of humans or devices?
The amount of RFI has definitely increased because there are so many more sources, both in terms of different kinds of wireless transmission technologies on various bands, such as WiFi and 4G networks, and in terms of point sources (millions of cell towers, millions of Blackberries and WiFi-equipped laptops) for each of these transmission technologies. Other, perhaps less obvious sources, include clock radios and halogen lamps.
I would love to see a Sherlock or Monkeys which talks about something that took place in the 21st century. But I digress. My point here is that one can't help but notice that RFI has actually increased in recent years. My beloved Blackberry is among the biggest culprits. Who among us hasn't been on a conference call where asychronous (actually, often persistent) buzzing is disrupting the discussion. "Can everyone check if their Blackberry is near the phone?" is a common question on these calls. I don't know how designers can easily stanch this interference. It's not like you can put a choke on the antenna without killing the signal. Still, it's a serious problem.
Good detective work, which unfortunately required a major effort on your part in terms of having to pick up and move. Forget about the inconvenience, the issue you raise about the effect of the RF disturbances on humans is really far more alarming. Glad you were able to clear out of dodge.
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