I love collecting these kinds of things. Not the devices themselves, but plans and schematics. This one has put me in a real tizzy.
quote:
A French engineer by the name of Professor Gavraud discovered by accident that the nausea attacks he was suffering in his office were caused by low frequency vibrations generated by the air conditioning plant on the roof of a building across the road. These vibrations were being conducted thru the air and because of the shape and the critical distance of his office from the air conditioner his office was "tuned" to the 7 cps being generated across the road. This constant subliminal vibration affected his nervous system and made him feel sick. Being an engineer he decided to build machines with which he could experiment. After a lot of testing he found that a 6 foot version of a French Policeman's whistle produced the subsonic sounds he needed. To make it work he powered it with compressed air. Apparently there was a fatal accident on its very first test. The technician operating it collapsed with crushed organs, such was the effect of the subsonic blast. They found that the low frequency waves could be "aimed" at a concrete building some distance away and under some conditions could cause the foundations to disintergrate. These devices became known as "Frequency-7" machines and copies of the patents are available from the French patent office.
I've managed these two URLs, but I can't exactly use them with even a modicum of proficiency.
http://www.inpi.fr/
http://www.inpi.fr/brevet/html/rechbrev.htm
I also found this site, which resulted in a few interesting tid-bits.
http://ep.espacenet.com/ - European Patent Office
From the EPO, I managed to find a "pest and burglar chaser" by Garaud Jean Pierre - FR2556485. This is a smaller, piezo-electric Frequency-7 device. Close, but no cigar. If I ever get the gumption and a decent workbench, I might make a slightly more powerful version of one of these in a fly-swatter configuration. You know, just wave it in the general direction of the annoying bug, it drops dead, and you go puke in the corner. Sounds like that would make for a fun night of drinking on the porch.
Also, the name thing is giving me some trouble:
Pierre Gavraud = Frequency-7
Garaud J. Pierre = "pest chaser"
Although, I'll be the first to tell you that I just might be chasing a mythical beast. I have been after many devices for years and have turned up nothing. However, I think there is a better chance that Frequency-7 does exist than other things that I've been after.
Anybody out there willing to help me find Frequency-7?
I'll take any leads that might get me the schematics or convince me that I'm chasing something that doesn't exist.