View single post by Bruce
 Posted: Jan 29th, 2010 04:00 PM
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Joined: Dec 12th, 2007
Location: Dunedin, Florida USA
Posts: 38

I spoke with my electrical engineer buddy about the California noise issue.  He said if a noisy power pole is the source of the "proper" field that it could have been generated either by arcing or by a corona  type discharge.  He favored the corona discharge because arcing would by its nature tend, over time, to melt or burn away any metal the arc was jumping to and the arcing would permanently stop.  Corona discharge on the other hand is more of a case where when conditions are favorable electricity discharges from the powerline directly into the air. 

He, Russ, also said that if you want to duplicate the electric field created by either arcing or corona discharge with precision the mechanical relay approach may be difficult to control to a constand 60 Hz frequency.  Russ suggested that the most straightforward way would be to use a Variac (variable AC transformer) and a small neon sign transformer.  The output of the neon sign transformer could be sent to an ordinary, electrically grounded automobile spark plug.  Then the variac can be used to control the voltage fed to the neon sign transformer thereby controlling the output voltage of the neon sign (high voltage) transformer.  By adjusting the variac voltage and spark plug gap you can adjust the intensity (power) of the spark.  That allows testing of the spark gap or arcing type electric field.  The spark plug could be removed and a piece of wire substituted to test the corona discharge type electric field. 

In either case you are going to broadcasting wideband signal that my jam your neighbors' radios and televisions.  Placing everything, including your radio, inside a grounded metal or metal screened box could mitigate and possible eliminate broadcasting your interference signal out to the neighbors.  He also cautioned that you are dealing high voltges and there must be thought given to safety issues.

The advantage of using the variac and neon sign transformer is that they are both operating at precisely 60 Hz since they run on house current.  I did a little Googling and found sources for both of these.  A brand new variable AC transformer (like a variac) can be purchased starting at about $50 and neon sign transformers for about $40.  If that is out of reach financially you and I can maybe work something out.  Like maybe I could buy it and lend it to you for as long as you need for testing.

Another less expensive approach would be to use an automotive spark coil and build a little driver circuit that operates precisely at 60 Hz.  This is more work to build but doable.

Whatch' think?