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DB, When asked about the cone, the specific questions you bring up were not mentioned in detail. The part of the email regarding the function of the cone is posted below.

"The presence of the cone (four elements around the whip), are the difference between a standard J-pole. The out of phase radiation is confined inside the cone and outside the cone the radiation is in phase. To understand the better performance of the antenna in comparison of the standard 5/8 Lambda, it is necessary to also consider that the radiation pattern has been maximized to irradiate on the horizon line and does not elevate like a standard 5/8 Lambda. Considering also the installation, the small current that descends on the first part (the most important) of the mast, near the antenna, is in phase (another small increase in gain) That is not true for a standard 5/8 Lambda."

The outer wiring is there to contain the field in both the Vector and the "coax" example. The difference is the load placed at the end of each. That is what will determine if the "shield" will become a radiator on the outside as well as a shield to the currents inside the transmission line. If the load is an end fed vertical as we see at the end of the cone on the Sigma, the shield would be expected to radiated CMC as well. The shield is the 1/4 wave cone and the source of some speculation.

I believe Marconi suggests the current can't travel back down the cone since it does not terminate in a high impedance. Since the source of this CMC is the end fed 1/2 wave at the top of the cone, the current must begin at the top of the cone and fold back over the outside of the cone regardless of the impedance across this path since it is the only path CMC can take from the 1/2 wave load. The fact it is also a resonant 1/4 wave element also makes it an efficient radiator of this CMC.

<blockquote data-quote="Shockwave" data-source="post: 494912" data-attributes="member: 10882">DB, When asked about the cone, the specific questions you bring up were not mentioned in detail. The part of the email regarding the function of the cone is posted below.&nbsp;&quot;The presence of the cone (four elements around the whip), are the difference between a standard J-pole. The out of phase radiation is confined inside the cone and outside the cone the radiation is in phase. To understand the better performance of the antenna in comparison of the standard 5/8 Lambda, it is necessary to also consider that the radiation pattern has been maximized to irradiate on the horizon line and does not elevate like a standard 5/8 Lambda. Considering also the installation, the small current that descends on the first part (the most important) of the mast, near the antenna, is in phase (another small increase in gain) That is not true for a standard 5/8 Lambda.&quot;&nbsp;&nbsp;The outer wiring is there to contain the field in both the Vector and the &quot;coax&quot; example. The difference is the load placed at the end of each. That is what will determine if the &quot;shield&quot; will become a radiator on the outside as well as a shield to the currents inside the transmission line. If the load is an end fed vertical as we see at the end of the cone on the Sigma, the shield would be expected to radiated CMC as well. The shield is the 1/4 wave cone and the source of some speculation.&nbsp;I believe Marconi suggests the current can&#039;t travel back down the cone since it does not terminate in a high impedance. Since the source of this CMC is the end fed 1/2 wave at the top of the cone, the current must begin at the top of the cone and fold back over the outside of the cone regardless of the impedance across this path since it is the only path CMC can take from the 1/2 wave load. The fact it is also a resonant 1/4 wave element also makes it an efficient radiator of this CMC.</blockquote>

[QUOTE="Shockwave, post: 494912, member: 10882"] DB, When asked about the cone, the specific questions you bring up were not mentioned in detail. The part of the email regarding the function of the cone is posted below. "The presence of the cone (four elements around the whip), are the difference between a standard J-pole. The out of phase radiation is confined inside the cone and outside the cone the radiation is in phase. To understand the better performance of the antenna in comparison of the standard 5/8 Lambda, it is necessary to also consider that the radiation pattern has been maximized to irradiate on the horizon line and does not elevate like a standard 5/8 Lambda. Considering also the installation, the small current that descends on the first part (the most important) of the mast, near the antenna, is in phase (another small increase in gain) That is not true for a standard 5/8 Lambda." The outer wiring is there to contain the field in both the Vector and the "coax" example. The difference is the load placed at the end of each. That is what will determine if the "shield" will become a radiator on the outside as well as a shield to the currents inside the transmission line. If the load is an end fed vertical as we see at the end of the cone on the Sigma, the shield would be expected to radiated CMC as well. The shield is the 1/4 wave cone and the source of some speculation. I believe Marconi suggests the current can't travel back down the cone since it does not terminate in a high impedance. Since the source of this CMC is the end fed 1/2 wave at the top of the cone, the current must begin at the top of the cone and fold back over the outside of the cone regardless of the impedance across this path since it is the only path CMC can take from the 1/2 wave load. The fact it is also a resonant 1/4 wave element also makes it an efficient radiator of this CMC. [/QUOTE]

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