It looks as if the NEC is here concerned not with electrical
characteristics, but with mechanical ones.
> [Original Message]
> From: Paul Christensen <firstname.lastname@example.org>
> To: RFI List <email@example.com>
> Date: 12/21/2008 1:46:42 PM
> Subject: Re: [RFI] DirecTV to ground or not to ground
> Under NEC 810.52, the AWG size for outdoor Tx/Rx antennas is even
> considered: For dipoles and other wire antennas, Table 810.52 specifies
> for antenna spans less than 150 ft (45m), conductors shall not be smaller
> than #14 AWG. Over 150 ft, (e.g., 160m dipole) requires either #10
> (hard-drawn CU), or #12 (copper-cladded steel). Further, the diameter of
> lead-in transmission line conductors are specified to be no smaller than
> antenna conductor size. So, according to the NEC, a U.S. station may not
> use #16 AWG ladder line with #14 AWG wire antennas. In no event should
> ladder/open line be less than #14 AWG.
> Reality check: So just how many of us are actually complying with the
> when we install our wire antennas? Odds are it was pure luck if your
> installation falls within the NEC requirement.
> Paul, W9AC
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