Thread: Vincent antenna
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Old December 5th 07, 02:01 AM posted to rec.radio.amateur.antenna
Roy Lewallen Roy Lewallen is offline
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First recorded activity by RadioBanter: Jun 2006
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Default Loading Coils; was : Vincent antenna

Richard Clark wrote:

Hi Roy,

The complaint is:
Wire 3 segment length too short. L = .01914 m; recommended min. =
.07495 m.
and so on for 800+ lines.

Attempting to find the Src Data results in:
Wires 3 and 10 contact improperly or are too close.
Wires 3 and 11 parallel and contacting.
Wire 3 end 2 contacts improperly or is too close to wire 12.
and so on...

However, on close examination
Pilot Error
The wire is too thick (I noticed this in modeling Tom's coil at the
Corum calculator and hadn't done the correction yet in EZNEC). The
geometry still complains, but it doesn't inhibit processing.

Thanx anyway.


Thanks for the additional info. EZNEC's checks are often not fully
understood, so I'll briefly describe what they do.

EZNEC provides two types of checks, segmentation (formerly called
guideline) and geometry. The first is advisory and tells when segment
lengths or segment length/wire diameter ratios are outside NEC
recommendations. As I mentioned in an earlier posting, warnings about
too-short segments can often be disregarded without significant
consequence, and this warning is often seen when a helix is created. The
geometry check looks for situations such as touching or overlapping
wires which can cause serious calculation errors. It takes finite wire
diameter into account, so sometimes the cause of a reported error
requires a bit of thought to determine, as it did here. EZNEC won't do
calculations if any geometry error is present because of the high
probability of the result being erroneous. The geometry check was
introduced in EZNEC v. 4.0; the segmentation check has been present for
a much longer time. NEC-4 has a check similar to but less complete than
EZNEC's geometry check, but no equivalent to the segmentation check.
NEC-2 has neither.

Roy Lewallen, W7EL