Hi Ignacy,
Salt water is very special! In a salt water environment potentially the entire Fresnel zone -- where as much a 6 dB of gain is obtained from ground reflection -- is in a highly conductive environment. Low angle radiation from a vertical with a salt water Fresnel Zone is much better than from an inland vertical. In a inland location only a very small fraction of the Fresnel Zone is covered by conductive radials. 73 Frank W3LPL ----- Original Message ----- From: "Ignacy Misztal" <[email protected]> To: [email protected] Sent: Tuesday, November 6, 2018 8:45:28 PM Subject: Topband: Accuracy of modeling of 160m verticals A number of articles analyzed 160m verticals by simulation. Once the height was lambda/8 and the number of radials >= 16 (buried) or >=4 (elevated), the difference in gain was at most a few db. I operated the 2017 Stew contest from a northern beach of St George Island, FL. The antenna was inv L about 55 ft vertical and 90 ft horizontal,. with one 70ft radial elevated 5 ft. The performance was astounding. EU was heard one hr before the sunset, in bright sun..During the contest, EU were only slightly weaker than the US. A special point was easily working a DL with 100W while a well known contester using high power 100 miles inland could not work it. So it seemed that the salt-water enhancement was like 15 db, not a few. I wonder whether simulations are inaccurate with respect to radials/soil type or is salt water special? Ignacy, NO9E _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
