[Elecraft] wire for random wire antenna using kx3

[Jim Brown]

This overly simplified equation fails to account for proximity effect.

On 12/17/2018 12:58 PM, John Oppenheimer wrote:
> On 12/17/18 1:58 PM, Jim Brown wrote:
>> In order of loss at dB/100 ft at 10 MHz from low to high, the
>> Teflon #12 is lowest at 0.94dB, then RG400 at 1.22 dB (about the same as
>> RG58), then #12 THHN at 1.34 dB. #12 or #10 enameled copper had the
>> greatest loss, 2.4 dB/100 ft.
> Hi Jim,
>
> Two parallel transmission line is the easiest of all to evaluate using a
> RF resistance table and knowing the impedance of the line.
> http://ve3efc.ca/wireohms.htm
>
> The wire loss is dB = 10 * log10((Zo + WireR)/Zo)
>
> Assuming Zo=100 for the #12 Teflon and THHN. R at 10 MHz = 4.24/100 =
> 8.48/200.
>
> Wire dB = 10 * log10(108.48 / 100) = 0.35 dB
>
> Using the two values above at 10 MHz, 0.94 and 1.34, the dielectric loss
> is 0.59 dB and 1 dB. The dielectric loss is about two and three times
> the wire loss.
>
> John KN5L
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to jim at audiosystemsgroup.com
>