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Oldtimer,

What does the VSWR curve look like for your A-99?

I attribute the bandwidth of this antenna (which does exactly what it was designed to do, by the way) to the matching circuit. I didn't expect it to be a broad-banded as a ground plane, as it has to match 3K or so to 50 ohms, and isn't starting out near 50 to begin with. The end fed halfwaves I have built used simpler LC circuits for matching as opposed to the tuned transformer the A-99 has, but I can't compare apples-to-apples since they were for lower bands. I may build one for 27 MHz sometime just to see, but right now that would be WAY down on my priority list!

The conditions you are seeing could be caused by the coax length just happening to work out in that case, or it could also be an indication of loss causing the greater bandwidth.

<blockquote data-quote="RickC." data-source="post: 317021" data-attributes="member: 9297">Oldtimer,What does the VSWR curve look like for your A-99?&nbsp; &nbsp;I attribute the bandwidth of this antenna (which does exactly what it was designed to do, by the way) to the matching circuit.&nbsp; I didn&#039;t expect it to be a broad-banded as a ground plane, as it has to match 3K or so to 50 ohms, and isn&#039;t starting out near 50 to begin with.&nbsp; The end fed halfwaves I have built used simpler LC circuits for matching as opposed to the tuned transformer the A-99 has, but I can&#039;t compare apples-to-apples since they were for lower bands.&nbsp; I may build one for 27 MHz sometime just to see, but right now that would be WAY down on my priority list!&nbsp;The conditions you are seeing could be caused by the coax length just happening to work out in that case, or it could also be an indication of loss causing the greater bandwidth.</blockquote>

[QUOTE="RickC., post: 317021, member: 9297"] Oldtimer, What does the VSWR curve look like for your A-99? I attribute the bandwidth of this antenna (which does exactly what it was designed to do, by the way) to the matching circuit. I didn't expect it to be a broad-banded as a ground plane, as it has to match 3K or so to 50 ohms, and isn't starting out near 50 to begin with. The end fed halfwaves I have built used simpler LC circuits for matching as opposed to the tuned transformer the A-99 has, but I can't compare apples-to-apples since they were for lower bands. I may build one for 27 MHz sometime just to see, but right now that would be WAY down on my priority list! The conditions you are seeing could be caused by the coax length just happening to work out in that case, [I]or[/I] it could also be an indication of [I]loss[/I] causing the greater bandwidth. [/QUOTE]

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