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I'd be skeptical of some of these models as I can clearly spot errors in a few. The Sigma IV at 36 feet looks nothing like the model posted with a peak gain over 45 degrees. The difference 12 inches in height makes at 37 feet is not even close to the reported 1.5 db. Way off on that one. The I-10K with slanted 5/8 wave radials has some issues too. How is it showing an extra db or more of gain with that intense mast / coax radiation that I'm nearly certain is out of phase with the radiator along the first half wavelength where the current is highest?

The 5/8 wavelength radials would also present a much higher driving impedance than the 1/4 wave radials. This should reduce the current flow in the 5/8 wave radials and their ability to decouple the mast or coax. That might explain why the currents on the mast / coax are actually higher than any other point on the antenna. It sure doesn't explain how the model shows improved gain though. This model would be more interesting to examine with the current phase option turned on.

<blockquote data-quote="Shockwave" data-source="post: 425064" data-attributes="member: 10882">I&#039;d be skeptical of some of these models as I can clearly spot errors in a few. The Sigma IV at 36 feet looks nothing like the model posted with a peak gain over 45 degrees. The difference 12 inches in height makes at 37 feet is not even close to the reported 1.5 db. Way off on that one. The I-10K with slanted 5/8 wave radials has some issues too. How is it showing an extra db or more of gain with that intense mast / coax radiation that I&#039;m nearly certain is out of phase with the radiator along the first half wavelength where the current is highest?The 5/8 wavelength radials would also present a much higher driving impedance than the 1/4 wave radials. This should reduce the current flow in the 5/8 wave radials and their ability to decouple the mast or coax. That might explain why the currents on the mast / coax are actually higher than any other point on the antenna. It sure doesn&#039;t explain how the model shows improved gain though. This model would be more interesting to examine with the current phase option turned on.</blockquote>

[QUOTE="Shockwave, post: 425064, member: 10882"] I'd be skeptical of some of these models as I can clearly spot errors in a few. The Sigma IV at 36 feet looks nothing like the model posted with a peak gain over 45 degrees. The difference 12 inches in height makes at 37 feet is not even close to the reported 1.5 db. Way off on that one. The I-10K with slanted 5/8 wave radials has some issues too. How is it showing an extra db or more of gain with that intense mast / coax radiation that I'm nearly certain is out of phase with the radiator along the first half wavelength where the current is highest? The 5/8 wavelength radials would also present a much higher driving impedance than the 1/4 wave radials. This should reduce the current flow in the 5/8 wave radials and their ability to decouple the mast or coax. That might explain why the currents on the mast / coax are actually higher than any other point on the antenna. It sure doesn't explain how the model shows improved gain though. This model would be more interesting to examine with the current phase option turned on. [/QUOTE]

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