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The analyses shown below provide one example of the difference in the radiation patterns of the EFHW system described there. **RADIATION ENVELOPE at 3.9MHz**


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My gutter antenna experiments revealed that the gutter (metal of course!) itself can be used as end-fed half-wave antenna on the self resonance frequency. The efficiency is poor: the losses to conducting environment are very high, even with dry weather. For reception such antenna can be used, but all the interference generated in the house is coupled to the ...


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First, what bands are you listening to? You should hear activity on roughly 20m – 40m during the day (and 15m sometimes), and 40m – 160m at night. This is close to the bottom of the sunspot cycle, so signals are often fairly weak, but there should be a few loud stations on 20m and 40m. Your antenna would do better to be higher, but it's high enough for ...


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The very best source of information that you'll find about making common-mode chokes is available at Jim Brown, K9YC's site http://k9yc.com/publish.htm. Download his PDF http://k9yc.com/RFI-Ham.pdf. RFI, Ferrites, and Common Mode Chokes For Hams Most recent update April 2019. This tutorial is directed specifically to RFI in ham radio applications. It ...


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You build a few and measure them with a vector impedance meter.


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"EFHW" means end-fed half-wave. It is by definition a half-wavelength long, so it is not short. And it's fed at the end, so it can't be a loop, which has no ends. I wouldn't say it's a very good choice for a space-limited application. There are loop antennas too, and any wire antenna can be bent or curved, though that may make it a very different ...


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Some antenna designs use multiple parallel elements like this. For example, fan dipoles. Or, as you can see the Butternet HF9V has a couple parallel wires hanging off it in the upper half: These extra elements add additional resonant modes to the antenna, which is what makes these antennas multi-band. In a fan dipole, if the elements are kept some distance ...


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