[time-nuts] Loran, GPS, Lightning, Timing

[Chris Albertson]

On Fri, Jun 27, 2014 at 6:10 AM, paul swed <paulswedb at gmail.com> 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