> Personally, I don't use random wires. For a long time I had a long random wire up and had a lot of success on it. But it would not tune on small segments o

> Personally, I don't use random wires. For a long time I had a long random wire up and had a lot of success on it. But it would not tune on small segments of the bands because the impedance was very high or very low. And it was relatively deaf near those points, too. I shortened it slightly until those dead zones were in places I didn't care about. As the wire gets longer, those scary multiples of half wavelength become more common (though narrower). E.g. if I have a 150m electrical length antenna, around 17.987MHz, 18.986MHz, 19.986MHz, 20.985MHz, 21.984MHz, are really bad. This is if the wire is straight and far above the ground. If it also has random bends, you get even more places where funny things happen. And then, of course, really crazy things happen when you start trying to use this as a receive antenna up on UHF-- 399.7, 400.7, 401.7, 402.7, etc, not to mention the unpredictable, strong, and varying directionality. > This is another case I haven't faced so far, neither myself or in the literature. 15k ohms? If the impedance really reached that high, maybe it's for the lack of a counterpoise, even if a small one? https://vk6ysf.com/longwire_antenna.htm https://vk6ysf.com/longwire_antenna.htm " A multi-band end fed wire antenna presents a potential problem in that a ¼ wave length antenna cut for say the 80 metre band will present a feed impedance of about 70 ohms however when the same antenna is used on the 40 metre band the feed point impendence will be several thousand ohms and therefore difficult to achieve a match even with a quality tuner. The trick is to making this type antenna an easier match by avoiding the lengths that are 1/2 wavelength and harmonically related to 1/2 wavelengths or simply multiples of 1/2 wavelengths that will present the most extreme rang of impedances." 4NEC2 graphs are in the article. Admittedly, 15k ohms is an extreme case: at some point, earth losses, etc, prevent you from getting all the way to infinity, and ohmic losses of the wire and feedline stop you from getting all the way to 0 ohms. Of course, neither of these mechanisms makes you better at radiating power or receiving. > I can't remember of any mode demanding more than 30KHz (again, I'm not implying they don't exist). Lots of exotic, interesting modes, but also --- AM radio. 15KHz is in the human audible range (of younger people) and some AM stations carry audio this high. Occupied bandwidth of an AM radio station is 2 times highest audio frequency conveyed. Also, you probably are a few KHz off in tuning of your magloop, so you may have e.g. 20KHz on one sideband and 10KHz on the other within the bandwidth of the magloop. In turn you get the weird phasing artifacts and attenuation of higher frequencies that comes from receiving only 1.5 sidebands.