My 256 ft center fed wire shows a 1.0 amp current in one leg and a 1.1 amp
current in the other leg. One leg goes through the top of a tree while the
other is over grass. Depending on season, leaves or no leaves there is a
noticed difference in balance/unbalance but no so as to cause a problem.
These measurements were done with a single Weston RF Ammeter, 0 - 2A F.S.,
with internal thermocouple. Measure one leg and note the current and then
measure the other leg. Pretty easy What were the currents you measured? .
The balanced feed systems are much more forgiving than many realize.
73
Bob, K4TAX
----- Original Message -----
From: "Carter" <k8vt@ameritech.net>
To: <tentec@contesting.com>
Sent: Thursday, May 15, 2014 2:24 PM
Subject: Re: [TenTec] Eagle problem?
On 5/14/2014 7:38 PM, Bob McGraw - K4TAX wrote:
If the line is operating anywhere near a balanced
> condition there will be little to no radiation from the feed line.
Well, I guess it depends on your definition of "little" radiation. In my
case, I have measured greater current in one leg of the ladder line than
the other. This does not surprise me in that the antenna itself (132 foot
dipole at 25 feet above ground) is anything but physically balanced. The
dipole is not in a straight line (bent at about 70 degrees), half of the
antenna is over grass, the other half passes over the house, different
halves are closer or further from trees, etc, etc all due to the lay of
the land and available mounting points (trees) --
so, anything but "balanced". Unless you are very fortunate or have your
antenna in hypothetical free space, unequal currents i.e. feed line
radiation, is virtually unavoidable.
73,
Carter K8VT
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|