On Fri, Jun 27, 2014 at 6:10 AM, paul swed <[email protected]> wrote:
> I have never seen an article using exotic special tubes. I understand that > benefit but common tubes do a fine job. I still believe it was a QST > article. Maybe 73 magazine. It was a long time ago. When I started using > the 12AU7s again for the vlf pre-amp they were $1 or so 7 years ago. Maybe used tubes for $1. New ones where never that cheap, even in the tube era when they were common. The 12AU7 is a current production tube. You can buy a brand new one for under $10. Collectors have pushed the price of pristine vintage tubes up but the BIG market for tubes today is guitar amplifiers. Factories in Europe, Russia and China are making millions of new vacuum tubes. The tube cost less then the power supply you'd need to run it. I actually think a vacuum tube would be ideal for something that has to deal with lightening. Even if it gets "fried", it's a cheap enough part in a socket that you can change it out in two minutes. Use a tube for the input end and fiber optic cable for the output and you'd be very safe during a storm. But the point of lightening monitoring is to share your data over a network and for that they need IDENTICAL receivers at each location. So even if you can build a superior LF amplifier it will not be so useful if you can't exchange data with others. -- Chris Albertson Redondo Beach, California _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
