[Prev][Next][Index][Thread]

Re: weather influence on TC performance



Robin,

This is one I've been trying to figure out for a while also.
Humidity will change the capacitance of your top electrode since the air is 
your dialectric medium between it and ground, and since the relative 
permittivity changes with the humidity level, you have to re-tune the primary 
to match the change in secondary circuit frequency.  Your spark gap(s) will 
also be affected due to a change in breakdown voltage, and you may need to 
change the spacing for best sparks.

Don't try and run your coil in foggy or misty weather.  The condensed water 
can make nasty paths for the sparks to travel.  If you have any wood for 
insulation between things, it can quickly become conductive in high humidity. 
Phenolic will also absorb water and can become conductive.

R. Scott Coppersmith

<< Original Poster: "Robin Copini" <rcopini-at-merlin-dot-net.au> 
 
 Hi all,
 
  I have a question involving the performance of TC's and the ambient
 weather conditions. For those that don't know
 I live in Adelaide South Australia - quoted as being the driest state in
 the driest continent on earth. Now for most of
 the spring/summer/autumn, (fall for you guys in the states), it's very
 dry and can get quite hot, temps 37  - 40 degC are quite
 normal for days at a time here.
 
  Usually this isn't a problem, but this year for whatever reason it's
 also quite HUMID, with levels between 65 - 80% fairly
 regular lately soooooo......
 
  My TC rather enjoys secondary arcing now instead of the nice arcs I was
 getting when it was not quite so humid. I still get
 arcs from the top load but they are vary numerous, (10 to 15), and
 fairly short, (2 to 3 feet), and at the same time an almost
 continuous secondary arc occurs, not much fun!.
 
 Now I'm assuming that it's the humidity but is there a cure or do I just
 wait until it dries out a bit?  I figure, given the wide
 geographic distribution of the members on this list that someone has
 encountered this before.
 
 Best Regards in now not so dry OZ
 
 Robin Copini.
 
  >>