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Wes Stewart wrote:
However, compare something like Andrew LDF4-50 to Wireman 554 and you find that the "lossy" coax has a loss of 0.48 dB/100' @ 50 MHz and the "low-loss" ladderline has a loss of 0.41 dB under the same conditions. Hi Wes, let's say I'm trying to choose between the two. Wireman 554 is about 25 cents/foot. How much did you say the Andrew LDF4-50 costs? :-) (LMR-1700 is about 8 bucks/foot.) Here's another way to look at things for multi-band non- resonant antenna lengths. The feedpoint impedance for that type antenna may vary from a low of about 50 ohms to a high of about 7500 ohms. To minimize SWR for all conditions, Z0 should equal the square root of those two values or 612 ohms. Given 600 ohm open-wire line, the SWR shouldn't go much above 13:1 for the open-wire line but may go as high as 150:1 for the coax. I don't know about you, but I would rather run with a maximum SWR of 13:1 rather than a maximum SWR of 150:1. -- 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! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
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