Fan Dipole : How it works, a simplified explanation.

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Fan Dipole : How it works. Aimed at anyone with an interest of DIY antenna building. this is a rather oversimplified explanation of how the "Fan Dipole" works.

As a cut length of wire is resident at a given frequency with a impedance of 50 Ohms, If you feed RF energy to the wire at the same frequency, the wire will radiate the RF with little to no returned energy. If however you move away from that frequency the impedance of the wire changes and the cut wire becomes resistive, the RF energy being pass it will start being return to to its source, (high SWR)

A Fan Dipole has multiple cut lengths of wire, resident and key frequencies and as the frequency changes so each length of wire becomes resident and the others represent high impedance and so become gated to the RF forcing the energy down the route of less resistance.

I do hope you enjoy it and subscribe for more..

Many thanks
Mike - M0MSN
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BTW... That's a great coffee cup!
Thanks for the clear explanation. It pinged a memory from my prehistory in circuit analysis class about current dividing in parallel circuits. If you apply a power (V x I) to a set of parallel resistances, the current in each ( I ) will be inversely proportional to the resistance of the branch. So if the voltage is the same across each branch, and the current varies, the branch with the highest V x I value will, by definition, produce the most power.
Presto! The antenna segment with the lowest impedance gets the most current and produces the most (RF) power!
I'm probably restating the obvious here, but it was an (admitedly low power) illumination for me. Thanks!

JimCliffe
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A good simplistic approach to explaining the alchemy of RF.

alanhewitt
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Yeah, good explanation. I wouldn't have thought of the child's toy bit, but it explains it well for those that struggle with it. Well done Mike.

BoBjjjjs
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Great video and easy to understand. I‘m right learning vor my Class E License in Germany.
You are a great Inspiration for this hobby.

Rotanrider
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Excellent explanation. I have built several /P fan dipoles, mostly 10, 20 & 40mtrs and tuned each leg little by little, but never really understood the "magic" behind it, now I do. Thank

theoldhobbit
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Wow. Brilliant way of explaining. Thank you

gilcomnz
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Nicely explained. I have an indoor fan-dipole and it works well.
I'm amazed your able to get the vswr so low with the ends of the wires being so close to each other.
All of the fan-dipole designs I've come across suggest keeping each dipole end well apart (18 inch) or so.

robjackson
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Terrific explanation. Learning a lot about antennas from you, Mike! 73

abrahamnorthhampton
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Thanks Mike love the round peg in a square hole analogy

foxonemdfh
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Brilliant explanation! Thank you Mike!

thorktjt
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That is a simple explanation and easy to understand 👍🏻

Ron_pdron
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Mike - cracking video! Callum could learn lot from you, hahaha (sorry Callum if your reading this but couldn't help myself mate)

MAV
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brilliant video, well done, very clear and understandable

hedgerowpete
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I did wonder. And now it makes sense. Thanks Mike 😀

Stezza
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I was following along fine with your description until you tried to use the analogy of the different shaped blocks. They're NOT 'different shapes", but rather different sizes of the same shape! In your first drawing, you drew antennas (antennae) of lengths that were exact doubles or halves of their adjacent ones (harmonic lengths, if you will). As a musician and guitar player, I recognize that these antennae will also resonate sympathetically on their first and second harmonics. I get the "path of least resistance" analogy. Is it more an issue of the "reactance" of each leg at the transmitted frequency that causes the resonance? Obviously, the transmitted signal is going through ALL of the legs. Is it the reactance to the frequency that causes each antenna leg to be resonant in the proper frequency or band? I'm thinking the signal is resonant to some extent on ALL of these legs!

DustInTheWindAZ
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I only watched for the mention of inclement weather things 🤔

Seriously though, I'm a fan of an hf fan dipole. No pun intended. Good video, well explained

GXDX
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Hello Mike great video super work. Radio magic. Its just works. 👍🏻
Motters M7TRS 73's

Mottersmotters
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Hi Mike,
Very plausible and understandable explanation. Stay safe. WJ3U

DonDegidio
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Beautifully explained!
A hexbeam works similarly to a fan dipole with the centre hub representing 50 Ohms.

Keep up the good work Mike and stay safe.
Kevin, VK4KK

VKKU
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Another great video, thanks. I’ve been experimenting with a homebrew fan dipole but I’m struggling a bit with the elements interacting with one another, simply too close I suspect. Irrespective, they’re a great idea and this video is a super explanation of the theory. 73 M0EUK

graemeeuk