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300 ohm to 75 ohm for an idiot

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wubs

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Hi, I've searched this forum but can't find the answer I'm looking for (though, it probably is here, but I'm not technical enough to understand it).

Is there a simple formula for calculating the turns ratio for a 300ohm-to-75ohm balun wound on a toroid form?

Honestly, I can't understand the numerous formulae I've seen here and via Google searches.

I intend to use either 24 or 28 AWG wire as this is what I have on hand.

My intention is to use these baluns on a homebrew 8-bay antenna, and want to make sure the two 4-bay sections are phased properly prior to mounting, as it will be in a very difficult place to access repeatedly.

Thanks in advance!
 

Without going into formulas and bloody boring details, take four pieces of 0.4mm wire and wind 2 1/2 turns through a balun core (has to be that one that looks a bit like binoculars) ..
For connections see attached picture ..

Rgds,
IanP
 

    W

    wubs

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Thanks for the reply, Ian, that was very helpful.

Sadly, the only electronics supplier near me does not have this type of core -- he only carries the circular toroids.

If I wound it in a bifiller fashion, would that work? I ask because I took apart two old baluns I had laying around and both had a singular circular toroid. I should have counted the turns on them and then re-wound them, but that's hindsight... :(

Regards!
 

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