To be brief: At a prior QTH a 100' tower was topped by 4 el 10/15/20
monobanders and shunt fed for 160. I started with 20 radials ranging from
60-130' to fit the property. Performance sucked for chasing DX. After going
to 60 radials I was able to work DX but only after a lot of effort. This was
with 1200W. I didnt think another 60 was going to be magic and the effort
was a PITA..
Next I laid down 5 50x4' lengths of 2x4" welded, then galvanized and plastic
coated fencing and connected to the #6 copper ring with short #12 stranded
copper jumpers. All of this was across the street from a fresh water swamp
and the water table was about 3' down in the back yard. Several 8' ground
rods probably helped with lightning protection but did squat for RF, except
for a thin layer of top soil it was all glacial sand.
The results were amazing, I blew thru pileups and quickly blew past DXCC.
The station also won a 160 contest and a pair of DX contests and confirmed
the first 160M JA from northern New England. This seemed to support Sevicks
paper that a lot of metal close to the base was more effective than spread
over acres of poor soil.
Nothing scientific claimed, just the end results.
When I moved here I decided to try elevated radials using sloping wire
elements hanging from guy wires of a 160' tower (now 180') for a phased
pair. The reason for this was solid rock from 8-24" down everywhere, this
was on top of the highest hill within many miles. The only instrumentation
was watching the feed impedance change as I added radials which were 130' of
either #16 solid enameled copper or stranded and insulated #18. These were
10-12' above ground and run thru tree branches and scrub bushes thru mostly
woods. No thought to velocity factor or coupling to the trees was given or
cared about. Going from 16 to 32 radials yielded no discernible change in
the impedance so I stopped there. Phasing was simple coax lines and relays
for a pair of cardiod and a figure 8 pattern. This yielded an effective 15db
or better F/B or F/S depending on the pattern which was good enough as I was
listening on Beverages and really didnt care about rejection, just gain and
performance in the aimed directions.
As DX and contest results showed the antenna kicked a**. That counts alot
more than reams of boring papers dreamed up by academia operating under the
publish or perish laws of their little clubs.
Last year I tore everything apart for a rebuild and started by actually
measuring the RF ground resistance so I could wind proper transformers for
the new 2 wire reversible Beverages. It ran 200-250 Ohms over about 10 acres
for 600-900' Beverages. This sort of explains why the elevated radials
worked so well and supported the decision to not even bother attempting on
ground radials. Ive also read several BCB reports where stations that
rebuilt or started new with elevated radials had to reduce power to conform
with initial as built field strength measurements as well as the new
installs by using simple field strength charts and math for the "perfect" on
ground system.
So much for comments on a useless antenna forum where the "experts" refused
to accept this. They probably still have their heads where the sun dont
shine.
Carl
KM1H
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UR RST IS ... ... ..9 QSB QSB - hw? BK
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