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Old July 24th 06, 08:31 PM posted to rec.radio.amateur.antenna
Cecil Moore Cecil Moore is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 1,614
Default Is It double bazooka less noisy?

Jim Kelley wrote:
Cecil Moore wrote:
The size of the charge Vs the dielectric determines how
much of the charge actually reaches the conductor.


Perhaps you mean the amount of charge Vs. the dielectric determine the
voltage.


size = amount = magnitude = amplitude. It is hard to visualize
how a charge could make it to the conductor without the migration
of a quantum particle.

The point with which Tom seemed to take issue was the implication
that an antenna with low DC resistance would have lower precipitation
static noise. I also disagree with that notion.


Both of you misunderstood the definition of "noise" that I was
using. With the feedline completely disconnected from the
transceiver, arcing occurred and that aural noise woke me up at
night. It was aural noise from the arcing caused by precipitation
static charge tansfer that woke me up and a low DC resistance
eliminated it.

Precipitation
static is the noise which is apparent when a relatively high flux of
ions impinges upon an antenna. Low DC impedance antennas won't
accumulate large amounts of charge or generate a static discharge, but
they are nevertheless sensitive to the static noise just as any other
antenna would be. In other words, you and Tom W8JI are both right - you
just don't know why. ;-)


When a charge hits a closed loop, there are two paths it can take
to equalize the charge around the loop. Only one of those paths
is through the receiver and that is a higher impedance path than
the other path. When a single-wire dipole needs to equalize the
charges between the dipole elements, there is only one path available
- through the receiver which often has a capacitor in series and thus
blocks DC charge equalization. This is, of course, not the only reason
that a loop is quieter than a single-wire dipole but is simply one of
the reasons.

Incidentally, "Quietflex" antenna wire, with its 1000v insulation
reduced the problem to an acceptable level in the Arizona desert.
I still use that wire for my dipoles.
--
73, Cecil http://www.qsl.net/w5dxp