Re: RF ground in an apartment.

On Tue, 22 May 2007 00:50:41 +0100, Chris Jones
<lugnut808@xxxxxxxxxxxxxxxx> wrote:

Steve wrote:

I live in an apartment, on the second floor. I am finally finishing
up a tesla coil, but I don't have an rf ground. Would placing a
ground plane of wire mesh work? How big should it be? Would say,
4x4ft suffice? The coil is appx 3ft tall, 7.5kV NST, 17.5in tall
secondary, really not too big.

Also, I want to build a faraday cage for the coil. It isn't
necessarily a large coil, but I don't want to cause any interference
for anyone. Is aluminum screen acceptable for a cage?

Also, I have a standard box power filter, mfg: corcom, model: 20VK6.
To keep rfi from entering back into the power line, do I hook the
filter up normally, with line going to line and load going to load, or
backward, with line to load and load to line?

Thanks for all help,
Steve

I would think about finding somewhere other than an apartment to run the
coil, as it is quite likely to upset the neighbours, and damage their
appliances etc. Do you know anyone who lives on a farm by any chance? If
not, the Faraday cage is a good start. If the coil is inside the cage, and
the ground of the coil is connected to the bottom of the cage, then the
thing you need to take care of is any wires that go in or out of the
Faraday cage. At the point where any wire goes through the cage, it needs
to be connected RF-wise to the cage. It doesn't matter whether the cage is
connected to the real ground two stories below, but the cage should be
connected to the ground of your power cable, and the live and neutral wires
should go into the cage by way of a filter, the ground casing of the filter
being connected directly to the cage. You will need a very good filter.
The most important thing about the Faraday cage is that any joins in the
mesh need to be really well connected, and all the way along, not just in
one place. It is unlikely that you can get a really good connection
between pieces of aluminium mesh if it is anodised or painted - you would
have to get that coating off and it would be difficult. If you can get
hold of some bare metal mesh then that would be ideal, maybe chicken wire
(galvanised iron wire with about half inch holes) might be OK if you could
solder the joins.

Chris

I think you're right. I may just wait until I have a house. I don't
want to risk damaging someone elses equipment, that wouldn't be very
responsible of me.

So, if the cage itself is connected to power ground, which in my case
is AC ground, as long as all wires going in and out are filtered
properly, there should not be any RF present on the ground wire?

Just to clarify, how do I properly decouple the wires going through
the cage? I'm used to seeing feedthrough capacitors in RF equipment,
something along this principle? I'm having some trouble figuring out
which ground is acceptable to connect where, but I will do my
research, and likely put this project on hold until I have a more
acceptable location.

Steve
.

Relevant Pages

  • Re: Aux Power Drive Unit Board Caught On Fire!
    ... a short and or bad coil. ... question if you are in the right place or if the wire is just broken. ... diagnosing a right ball popper that wasn't firing and coil is good, ... Grey/Yellow wire connection and it does. ...
    (rec.games.pinball)
  • Re: OT Question for Iggy
    ... superconducting magnet with a homogenous cylindrical volume of about 2" ... It's the magnet for a Fourier transform ... For whatever reason Oxford favored small diameter wire and lots of turns, ... which has the effect of making the inductance of the coil very large. ...
    (rec.crafts.metalworking)
  • Re: DiMarzio humbucker in an Ibanez guitar (5 way switch)
    ... and then take the bare and solder it onto a separate ground lug. ... Next - take the red wire and wire it the same as the hot wire on the ... your coil tap) to where the white lead was on the Ibanez. ... some pickups DiMarzio makes have good designs for getting both humbucker and ...
    (alt.guitar)
  • Re: TECH: Aux Power Drive Unit Board Caught On Fire!
    ... ran a long wire from the violet/yellow popper coil connection to point ... had a Grey/Yellow wire connection and it does. ... will continually test when I put the wire onto the 1P11-5 point with a ...
    (rec.games.pinball)
  • Re: Mercruiser Still Wont Start
    ... 12V to the coil thru contacts in the slave solenoid. ... If you can crank it then you do have power to the system. ... beginning point to see if you have 12v being supplied to the wire lead. ...
    (rec.boats)