Re:Humid atmosphere

>>>Re: Body capacitance effect on coil tuning
>>>	Something is badly amiss there.  I can't imagine your coil
>>>being that sensitive to the effect of someone nearby.  A change of
>>>a percent or so in resonant frequency seems reasonable, b ut not
>>>much more unless your coil is enormous.  I would think a person
>>>15 feet away from even a four foot high coil would have an almost
>>>unmeasurable effect when the coil was firing and the "
>>>"Q" reduced by the spark loading.
>>>Ed Phillips
>>>Ed. I agree with you. Something is strange out here. I measured the
>>resonance again and asked someone else to move from 50 ft towards the coil.
>>(The coil is about 5ft 8" high). As they aproach you can see the resonance
>>change dramatically on the oscilliscope. At around 15 ft away the coil no
>>longer tunes in to any resonance within range. This only happens in the
>>jungle atmoshere and not in town. Have you any way to imitate the high
>>humidity and temperature to test this on your coil? It is 32 degrees Celsius
>>and 100% humidity in the evening. The heat prevents any condensation and
>>everything remains dry until dark. I have now removed the coil as I could
>>find no way to make it work in these conditions but would still like to know
>>what effect was preventing it from operating.
>>Thanks for the reply,
>>PAUL MILLOTT (Failed again)
>You may have come up with a more profitable use for a Tesla coil than 
>making spark shows.  It sounds like you have a very effective personnel 
>detector capable of use in heavy jungle.  Have you tried asking for a 
>multi-million dollar government grant to study the obvious military 
>applications of this?  If you did get big support, somehow I would 
>not be suprised.
>That phenomenon certainly is a poser!  Think of it on the bright 
>side.  You have a coil system that requires 50 foot clearance for 
>(safe) operation!!!!!!
>Happy Coiling!, rwstephens
Timing of some of these threads is spooky!

This last weekend I ripped out the primary of my old baby coil I 
bought from Information Unlimited and made a new primary with the
saucer shape and form fins cut from plexiglass just to try it's
construction. All went extremely well and the primary looks great.
Just on first go I was getting 8" streamers....better than the coil
had ever done. Then I went to do measurements.
I took the secondary to my work bench and rigged up a 555 Timer
circuit and played with caps and resistors until I found resonance
of the secondary. Then I took the timer signal and shot it into
the primary, put the secondary back in and hooked a scope to the
secondary output. I was mis-coupled only by 1/16" so I had made a
lucky guess in the beginning. I did notice on the scope that as
I walked by (6 feet from the coil), not only did the frequency
change on the scope but the signal amplitude as well!
I did not think to much of this at first but discovered this effect

(Info -I am just using two brass spheres as my spark gap.)

After firing up the coil and adjusting the spark gap distance wider
for greater output, I would have some good sparks going until I
backed away from the machine where as the gap would shut down every time.
I added more torroid to the top and retuned but with same results. 
Even though I know that the spark gap is a terrible quencher I wondered
why it would not shut down until I was away from the coil.

Bob Schumann
==  If you understand, things are just as they are.        ==
==  If you do not understand, things are just as they are. ==