Re: First darkness :-(

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "davep by way of Terry Fritz <twftesla-at-qwest-dot-net>" <davep-at-quik-dot-com>


>Well I finally got to testing the coil for the first

>time this evening.
>With probably the most disappointing results ever.

>Nothing! Well the spark gap fired continuously but I got

>nothing on the toroid. Even after removing the
>toroid and retuning (well gueesstimating) I didn't even get

>a 1" streamer.  I'm not quite sure what's wrong. Probably

>a combination of many things.

>First of all, my ground doesn't seem to be functioning.

         I'd regard this as a lower priority.
         (I'm partial to good ground, however would not
         expect lack of one to stop operation.)

>I drove 4 2" (ft?) pieces of 3/4" copper pipe into the

>ground so only about 3" were showing.  I then connected

>these in parallel.

         Might be instructive to check resistance from one to
         the next.
         (However I'd concentrate elsewhere as to why things
         are dark...)

>I didn't test them until afterwards but found when I put a

>light connected to hot

         Mains hot?

>and to my newly created ground, I didn't even get a dim glow.

         What size light bulb?
         IS it the mains hot?
         What resistance from manins ground to rf ground array.


>I didn't try to test the resistance but I would't doubt it's quite high.

         Its not unheard for their tio be anomalies in the
         mains wiring and/or grounding.

>I don't know why those pipes aren't working. I would think they're quite 
>below the frost line (I live in Massachusetts

>so the ground is frozen here).
         down to about 12" or so, at a guess.  varying from

         place to place.  Again, investigating the ground,

         while interesting, maybe less productive than other
         matters.


>Here are the specs of the coil:
>variac 140V output at high
>12/60 nst
>greg filter
>geek group cap (8 in series)
>spark gap air blast one gap (probably one of the main problems)
>primary, flat, 10" inner diameter 15.5 turns with .2" between turns
>second external tap primary. 4 turns with 1.5" between turns 18" diameter 
>helix


>(I tried bypassing the external tap primary as well as using all of it)
>secondary, 4.25" outer diameter, 28awg magnet wire. 22"
>Toroid, 6" dryer pipe, 29" outer diameter
>Tuned with toroid secondary resonates at 120kHz
>Primary resonates without second tuner at 120kHz as well
>(both tested with oscilloscope)
         If a scope is to hand:

         If Tesla system fired up with an 'antenna' on a scope
         input:
                 Does it pick up oscillations?


>I think my first problem is a coupling problem between the primary and the
>secondary. I've got over 4" from inner turn primary to bottom of first turn
>secondary and I think the coupling factor is completely off.


>Unfortunately I don't have anything to measure inductance at my

>house so I'd have to bring it to MIT's circuitry lab to test it

>and it's quite a hassle.  I think a good solution might be to

>make some more windings for the inside of the  primary and
>just solder the end of it to the current primary so I reduce the distance 
>to the secondary at the same time as lowering the

>resonant frequency of the primary so it's a bit below the

>secondary to make up for the difference caused by the ion cloud.

>I also think my air blast gap probably isn't very sufficient.

         efficient?

>I thought it would be ok since I just wanted to get a preliminary

>test with it.  It's two flat head screw driver bolts blasted with

>a fish tank air pump. Yes, you can laugh, I know it's mostly

>useless but I just wanted to try it.

         Is it arcing or sparking?

>I think  next I'm going to try a multi gap using 3/4" copper tubing.

>  That seems the most successful easy way.

>A third and final problem that I see other than the ground is the

>toroid is a bit oversized for that nst.

         Running without the toroid, as a test should have
         resolved this?

>It's just too big.

         Or the addition, for test, of a breakout point,
         as others suggested?

>I have another capacitor bay that I'm going to use for my next

>coil and I'll get another 12/60nst. That should put out enough

>power for that toroid but unfortunately right now it's just

>not very good.
         I'd start with basic checks: caps ok, wiring ok,

         (sounds rude: but I've made enough mistakes that...),
         is the system oscillating (scope of field).

=============================================================
[from a related reply:
>Pour water on the ground rod area for added conductivity
         More more less ineffective in sub freezing temps.
         (it hit '0F' 'here' (about 20 mi from MIT) last
         night.

>(ice can't hurt :-)).
         Ice is an isulator.  Water to ice, on the surface,
         will not affect the situation, either way.
]

         best
         dwp

...the net of a million lies...
         Vernor Vinge
There are Many Web Sites which Say Many Things.
         -me