Measuring Ground Wire Current – A Case Study

 

Shown below is lot and home layout. 50 foot tower is nestled in corner of the “L”.
Lot size is 70 feet wide and 110 feet deep.

See notes at bottom of the page.

TowerRadialX

  • Measurement with MFJ-854 RF Current meter
  • Unit values are relative numbers on a 0 to 100 linear scale
  • Base of my tower is the single point ground
  • Notice decreasing current measures at distance from tower increases
  • There are two 8 foot ground stakes are at the base of the tower. (there is also a 8 foot ground stake in the tower hole, under the tower, trust me)
  • There is also a ground stake acting as a tie point located at the rear of the house
  • The 5/15 at the X near the tower is a measure at the point of a cut radial due to garden activity. I put the meter on the end of the cut wire (5 on the meter) then spliced the connection and increased to measure 15.
  • Notice the low current on the left direction wires leading from real ground stake toward the tree. I feel this shows that radials work best when on a radial path from the single ground point. If a wire doubles back on itself, it will do no good.  Further I doubt tieing the far ends together will help things at all.
  • I measured current around to the right and to the front of the house by the hedge.  Notice how the current falls off as distance from tower increases.   I was still measuring current by the hedge at a distance of 70 feet.
  • Notice the current is 100 leaving the tower to the rear of the house. We have 60 at the ground post in the rear and then the current fans out from there. Notice the sum of the fan-out currents roughly add to the 100 running on the 4 ga. solid wire.
 Posted by at 3:47 pm