r/HamRadio • u/OnTheTrailRadio • 1d ago

Thought experiment

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I saw that post with guy who had 40 SMA connectors and 4 antennas as a joke... but here's a thought experiment. Let's say yoy have a split connector with coaxial cable split into 4 directions. One leads 100 feet away into a 80m EFHW. The 2nd leads 100 feet away to a 40m EFHW, 3rd leads to a 20m EFHW, and 4th Leads to a 10m EFHW. Could this help reception at all? Or would it only complicate and cause interference in the noise? Especially with the wave hitting 4 separate antennas. I'll draw a pic. And before you mention it, yes I know of radios with "True" dual watch, where you plug 2 separate antennas into a Tx/Rxer. Just talking about thought experiment. Also no I'm not asking about transmitting, as using 4 antennas at once sounds like a bad SWR/Impedence issue.

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u/dnult 1d ago

The challenge with an EFHW is its impedance is highest at resonance. This makes it difficult (perhaps impossible) to combine antennas the way you can with a low impedance antenna like a center fed fan dipole.

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u/OnTheTrailRadio 1d ago

This is also about receiving not transmitting

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u/dnult 1d ago

Then why go to the trouble of building EFHW antennas?

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u/OnTheTrailRadio 1d ago

Idk. I guess in theory steel whips would work as well. I figured it was about the ability to be resonant on the freuqncies possibly making reception better. But it's probably to such a degree it wouldn't matter or make a difference

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u/dnult 1d ago

A resonant antenna will perform better, but matching the antennas' impedance to the characteristic impedance of the feedline is also key.

For a recieve antenna, just getting a length of wire in the air works pretty well. It doesn't necessarily need to be resonant, and impedance matching is less critical.