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Cecil Moore wrote:
Reg Edwards wrote: The complete equation is - Attenuation = R/2/Ro + G*Ro/2 Nepers where G is the conductance of the dielectric, which is small for materials such as polyethylene and Teflon. And 1 Neper = 20/Ln(10) = 8.686 dB. Reg, I didn't disagree with your equation. I disagreed with this statement of yours: The number one reason for attenuation being higher is because the conductor diameter is smaller and, as a consequence, its resistance is higher. As an illustrated example: Assume a parallel feedline made from #24 wire and having a characteristic impedance of 600 ohms. What size would the wire in 50 ohm coax have to be to equal the HF matched line loss of the #24 600 ohm line? (The wire in the coax has to be 12 times as conductive as the wire in the parallel feedline in order to offset the effect of Z0.) A rough estimate indicates that the #24 600 ohm line has approximately the same matched line loss as RG-213 with its #13 wire. -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups ---= East/West-Coast Server Farms - Total Privacy via Encryption =--- |
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