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<blockquote data-quote="Jason Glass" data-source="post: 68050" data-attributes="member: 2167">Re: Best coax for paddlesHi Silas,Actually, I know this antenna quite well, but I did look it up before I posted to be sure of my accuracy.&nbsp; However, I should have more clearly written, &quot;the lowest boost setting of +6dB is too much...&quot;&nbsp; I also posted that the LPDA is inherently +6dB while Shure claims +7.5dB for the UA874.&nbsp; Please accept my apology for these oversights.The schematic printed right on the UA874 amp clearly shows that 0dB is not a pad, but passes signal directly from the LPDA elements.&nbsp; The nomenclature indicates the selected gain/attenuation of the amp/pad device, rather than the total gain of the antenna/amp/pad system.You will probably have satisfactory performance if you continue to operate the amp as you are now at 0dB.&nbsp; You might even try the -6dB pad if you run into situations where your receivers show overload on the meters.The issue of excessive gain is more complex than it appears, because efficient antenna designs like LPDA and Helical achieve extra gain on-axis while attenuating signals off-axis.&nbsp; Under certain very specific circumstances, that type of gain can be selective and beneficial.&nbsp; For example, when you know in which direction interference sources are located (which you can sometimes find at <a href="http://tvfool.com/index.php?option=com_wrapper&amp;Itemid=29" target="_blank">TV Fool</a>), you can aim the antenna to get somewhat selective gain within your performance area.&nbsp; Using active wide-band amplification can&#039;t be selective because it amplifies all signals, on and off-axis, including noise.&nbsp; Just FYI.</blockquote>

[QUOTE="Jason Glass, post: 68050, member: 2167"] Re: Best coax for paddles Hi Silas, Actually, I know this antenna quite well, but I [I]did[/I] look it up before I posted to be sure of my accuracy. However, I should have more clearly written, "the lowest [B][I]boost[/I][/B] setting of [I][B]+6dB[/B][/I] is too much..." I also posted that the LPDA is inherently +6dB while Shure claims +7.5dB for the UA874. Please accept my apology for these oversights. The schematic printed right on the UA874 amp clearly shows that 0dB is not a pad, but passes signal directly from the LPDA elements. The nomenclature indicates the selected gain/attenuation of the amp/pad device, rather than the total gain of the antenna/amp/pad system. You will probably have satisfactory performance if you continue to operate the amp as you are now at 0dB. You might even try the -6dB pad if you run into situations where your receivers show overload on the meters. The issue of excessive gain is more complex than it appears, because efficient antenna designs like LPDA and Helical achieve extra gain on-axis while attenuating signals off-axis. Under certain very specific circumstances, that type of gain can be selective and beneficial. For example, when you know in which direction interference sources are located (which you can sometimes find at [URL="http://tvfool.com/index.php?option=com_wrapper&Itemid=29"]TV Fool[/URL]), you can aim the antenna to get somewhat selective gain within your performance area. Using active wide-band amplification can't be selective because it amplifies all signals, on and off-axis, including noise. Just FYI. [/QUOTE]

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