Some field experiment results from 2016
Location: large farm field
Antenna: Inverted L, using two 21m masts
Note: this theoretically puts Rs at around 18 Ohm
Ground:
- Checken mesh: 6 pieces 8x1m crossed under the TX vertical, which
offers almost 100% coverage at 8m diameter
- PVC insulated copper-wire radials, 40 pcs 85ft/25m
Antenna Analyzer: AA-54
After finalizing the antenna Z=28.2 Ohm
Two days later we dismantled the antenna, but performed some
intermediate measurements.
chicken Mesh + 40 radials Z= 25.4 Ohm (lower because the inv-L part
started to sag)
chicken mesh +40 radials(rads all electrically disconnected) Z=33.4 Ohm
chicken mesh only (radials removed from site) Z=38.7 Ohm
I can not draw any conclusions from this single setup experiment.
Pictures available at
https://www.flickr.com/photos/pa5mw/albums/72157663223247069/with/24490646102/
73
Mark, PA5MW
On 6/3/2018 10:14 PM, Peter Bertini wrote:
Why would bonding the added matting be required if it is laid over or
beneath an existing radial field? It reduces ground losses regardless.
Peter
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