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

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

I am not too concerned about a direct hit as the antenna would be under the roof, and I have not had a direct hit to the house (yet) in 22 years but I am concerned about a close hit that could still generate hundreds of volts. I regularly (like every year or two, yes, it is getting old) replace TVs, networking gear and other various electronics even though I have surge protectors everywhere.

Didier KO4BB

On June 25, 2014 4:46:07 PM CDT, Chris Albertson albertson.chris@gmail.com wrote:

--
Sent from my Motorola Droid Razr HD 4G LTE wireless tracker while I do other things.

The only C.L. Stong (W2PFM - great call!!!) article that I could find at QST
came up in an archive search:  "How to Cook a Ham" from March 1947

A story about not having safety interlocks and getting zapped.

http://p1k.arrl.org/pubs_archive/28044

You need to be an ARRL member to access the file.

I also searched for "Lightning" and found nothing about detecting nearby
strikes, only about protection. Searched from around 1980 back through 1940.

Same for e-field.

Dave
KF7VNE

C. L. Stong wrote The Amateur Scientist articles in Scientific American
magazine for many years, throughout the 1940s - 1960s and later period.
As a child, I read these avidly and built many of the things he
described. I did not know he was a ham!

All The Amateur Scientist articles are available on a CD. I particularly
remember building a nuclear magnetic resonance spectrometer (well, a
simple one) in the late 1950s from one of his articles.

Scientific American magazine today is a mere shadow of its former self,
due mainly to a new publisher imported from Popular Science magazine.
There is no longer an Amateur Scientist article in each issue.

Larry W6FUB

On 6/27/2014 9:34 PM, DaveH wrote:

...

--
Best wishes,

Larry McDavid W6FUB
Anaheim, California  (SE of Los Angeles, near Disneyland)

Amen to that!  It's also turned from reporting to preaching-political!

I always wanted to build the amateur scientist stuff, but there were always
the lines with arrows off the figure "to power supply". Wonder if that's why I
have hell boxes full of old power supplies:-)
Probably a darned good thing I didn't build the x-ray tube!
Don

--
"The power of accurate observation is commonly called cynicism by those who
have not got it."
-George Bernard Shaw

Dr. Don Latham AJ7LL
Six Mile Systems LLC
17850 Six Mile Road
Huson, MT, 59846
mail:  POBox 404
Frenchtown MT 59834-0404
VOX 406-626-4304
Skype: buffler2
www.lightningforensics.com
www.sixmilesystems.com

QST lightning radar. But what a mess you get with google and every
lightning and radar TV station in the US.
Oh well if your replacing TVs every few years whats a few more opamps?
Now how does a poor man build something for what started this whole thread?
Time for me to hop off this thread.
Regards
Paul
WB8TSL

On Sat, Jun 28, 2014 at 2:37 AM, Don Latham djl@montana.com wrote:

On Fri, Jun 27, 2014 at 11:34 PM, DaveH info@blackmountainforge.com wrote:

There are a number of products on the market that make use of lightning
detection and ranging. The BF Goodrich "Stormscope" is based on that. There
have to be some documents around on its design. It is, in essence, a LF ADF
and somehow qualifies the envelope to deduce range to the strike which it
then displays to the pilot.

--
Brian Lloyd
Lloyd Aviation
706 Flightline Drive
Spring Branch, TX 78070
brian@lloyd.com
+1.916.877.5067

There is actually a lot of information on lightening observation.  If you
have access to a university library.  Some public libraries have on-line
databases you can search too.  Google is not so good at this as most of
the papers are in journals where you need a subscription, or more likely a
library that has a subscription.

I used to own a sail boat and took an interest in lightening and red a
bunch about it a few years back.  You can guess why.  On a boat on the
ocean you are very exposed, If a storm comes you can't simply get off the
water so there you are living under a 65 foot aluminum pole which is the
tallest conductor for miles and miles around.  So what to do about it?

I looked around and the most of the answers where coming from the
University of Florida.  They have some good "How To" publications if you
want to survive direct hits (to cover the sailing example) and also theory
but about detection, they have a "lightening observatory" there are there
are papers describing the instruments.  They observe the normal LF but
also up in VHF and even x-ray detectors.  Techniques are described for
determining the types of strikes (polarity) and some time they cn see
plrity reversals in cloudsand cloud to cloud discharges.    Once you find a
few survey papers they will have a long list of citations and you can hunt
down those papers.    A good search phrase is "Lightning Observatory in
Gainesville "

I think before anyone builds any detector it might help ask what data you
want.  Are you wanting to simply detect that lighting is nearby so you can
disconnect equipment or do you want to characterize the lightening in some
way?    It turns out almost always you need to know the location and this
means you need to make observations from sites that are some miles apart.
What a good TN application.  You need to have good time so you can combine
the measurements.

What I learned about the boat is that I needed a VERY good conducting path
from the mast to the saltwater.  This was made somewhat easy on my boat
because I had a 7,000 pound lead keel in contact with water (except for
some paint) and the mast was keel stepped.  Give the current a nice easy
straight line path and it will take it and not bother you.

On Sat, Jun 28, 2014 at 6:52 AM, Brian Lloyd brian@lloyd.com wrote:

--

Chris Albertson
Redondo Beach, California

A PDF of the 1960 book can be found here:

http://www.sciencemadness.org/library/books/projects_for_the_amateur_scienti
st.pdf

Dave