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Re: [TCML] pole pig question ###

Yep, I have have to totally agree with the good doctor
about grounding one ear of the pig. As a matter of fact,
since you can ground one ear of the pig, this means that
you can indeed use a SINGLE eared pig and use the
case as the return ground. "I" tie this case ground of the
pig to the RF ground and leave it isolated from the mains
ground since I also tie both the primary and secondary
coils' base to the RF ground as well.

I think DC and I may veer a bit in our opinions in how
you get the HV from the pig to the base of the coil. "I"
like to use x-ray cable and let the outer shield be the
RF ground while letting the inner condutors carry the
HV potential. DC has had issues with the Blumlein ef-
fect from using some type of coax for the transmission line
but I have never had any problems with this using x-ray
cable, but that's another thread/discussion.

He is also totally correct in playing it safe by completely
unplugging the power before "laying on of hands" to the
naked conductors of the primary circuit. Also, make
darn sure that the capacitor(s) is completely discharged
(better yet - crowbar shorted!) before doing this.

David Rieben

----- Original Message ----- From: <resonance@xxxxxxxxxxxx>
To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
Sent: Saturday, January 26, 2008 7:26 PM
Subject: Re: [TCML] pole pig question ###

a typo  ---- should be   NEVER trust your life to a relay or switch.

Dr. Resonance

Best to ground one of the pigs bushings, ie, run it single ended ouput.

also, NEVER just "shut off the power while adjusting pri tap".  This is
suicide.  NEVER trust your like to a switch or relay.  ALWAYS UNPLUG the
power cord from the wall before going anywhere near the pri coil. ALWAYS.
 Then it can never bite you, and one bite from a pole pig usually results
in death not just a shock.

Dr. Resonance

This is how I would hook it up.

Connect 240 VAC to the transformer primary with the variac connected in
series in one of the lines.

Put a choke coil on the each High Voltage terminal and connect them in
parallel with the spark gap.  Do not ground any of the HV terminals.

Connect a wire from the other side of the spark gap to 1 side of the

Connect a wire from the other side of the capacitor to the inside turn
the primary coil.

Connect a wire from the other side of the spark gap to the aligator clip
wire that goes to the other end of the primary coil.

No choke coils in the HV lines at the primary coil.

Connect the bottom end of the secondary coil to a GOOD earth ground.

Connect the strike rail around the outer edge of the primary coil if you
have one to earth ground too.

Toroid or sphere for the top load.

Turn on the 240 VAC crank up the Variac and adjust the primary tap for
best resonance frequency.  Needless to say always turn off the voltage
before moving the aligator clip to another primary tap.

Be sure you have a cooling fan on your spark gap other wise it will over
heat and your coil will produce sparks for only about 10 seconds or
the spark gap gets too hot to function correctly.

I like to use 12 guage solid copper insulated house wire for all my
connections it makes it very easy to bend the wires and put them exactly
where I want them and they stay there.  Make sure all wires have plenty
clearance to prevent arcs to other places.



-----Original Message-----
From: Jim Calvin <jcalvin@xxxxxxxxxxxxxxx>
Sent: Jan 16, 2008 4:25 PM
To: 'Tesla Coil Mailing List' <tesla@xxxxxxxxxx>
Subject: [TCML] pole pig question

Hi guys,

           I am trying to test my 25KVA  pole pig.  I am not running my
coil yet.  I wanted to test the system out.  So this is how I have it

I have a 240Vac input with a 7.8kKVA variac with a control switch.  I am
using the variac to regulate the voltage.  I have a 6.5mH choke (hand
using 10 gauge wire) in series with the primary.  I have a .05uF (at
capacitor connected to the HV output of the pole chicken as a test load.
One of the
HV outputs is connected to GND along with the pole chicken can.  My
variac is in
a control box with a voltmeter and a current meter.   I have a fluke
across the input 240Vac of the pole chicken after the ballast.  Between
the two
volt meters I was going to check the voltage drop across the ballast see
the it was doing it's thing.

I set the varaic at a 100V using the meter in the control box before I
switch it on to the pole chicken and ballast.  When I switch it on I
expect the voltage in my panel meter to stay the same and my fluke meter
be slightly less because of the drop across the ballast.  I figure my
should draw about 8 amps out of the variac.

Well when I turn the switch on the power to the pole chicken and
fluke meter is giving 110v and the meter in my  control box jumps from
to 110V (aprox.  It is an analog meter).

Then I decided to use my oscilloscope (I am part owner of design
company and I have access to this equipment) and check the voltage
the ballast and after.  Well the voltage after the ballast went up just
the fluke had shown.

What am I doing wrong?  Is it possible that the HV output is leaking
the primary?  What is the isolation voltage between primary and

I got this pole chicken from T&R electric.  It was actually a gift from
of friends/fellow coilers).  It is supposed to be new/reconditions and
checked by them.

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Dr. Resonance

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