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![]() Try one; prove me wrong; I dare ya! Regards, JS I don't see where the "inventor" of the DLM style antenna has violated any laws of physics... He has simply found the sweet spot of mixed C & L and short straight radiating sections along a shortened antenna to pull it into resonance while maintaining a a flatter SWR curve... With the helical lower section if that is how it is actually functioning also acting as an auto transformer he simplifies the matching of the feed point to coax... Sevick proved that shortened antennas can work well... If you look at the Fisher Island data for the DLM it shows that the gain of the antenna improves considerably with top loading - a finding we would definitely expect in a shortened monopole... Authors from Sevick, to Cebik, to W8JK, to W8JI, have championed the benefits of top hats for short antennas... BTW, we have the oposite end of the spectrum in the distributed capacity antenna with multiple caps along the length to redistribute current peaks... So using capacitive reactance to redistribute current along the antenna is well known and documented... All in all, it sounds like a fun antenna, John... The guys really ought to be looking at this as a method of trimming 160 and 80 verticals to a more manageable size while retaining some bandwidth and having easy matching... If I didn't already have full size antenna arrays for these bands I would be out there building one to see how it performs... I would hope that all those posting on the topic have read all the URL's provided - and also noted the point that the antenna benefits from being elevated and having elevated radials to work against , even whilst mounted over the excellent ground plane of the Navy's test range - a major piece of information...... denny / k8do |
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