DIY 4:1 UnUn for Ham Radio Antennas 

I CALL MY WIFE A UNUNE SHE THOUGHT I WAS CALLING HER ANOTHER WOMANS NAME . 😂never a dull moment

Thanks for the video, I was afraid of making a 4:1 because I saw two different ways of making them and didn't know which one to make for an OCF dipole, now I do!!!!

Looks good Ape , I like those binding post slick setup!

Ape splaining is relaxing and educational. I love it.

Gotta love a Dremel! Mine is approaching 25 yrs old & still going strong. Nice 4:1 UnUn!

Simple, clear and relaxed! From the guy in Florida with the vertical on a fence. Thank you again!

I like seeing the mechanical differences between the balun and the unun. Keep them coming! 73

Another golden video by Ape!! 👍👍👍

Nice job!

Good build

Fancy pants 'splainin glasses!

Looks awesome! Is there a best guess on power rating?

Oh, that must be suitable for the OCD antenna.😂

Smooth

Ladder line to Coax? Thanks Ape

Great video. If i miss the link please help link the core and the pl259 female connector,the wire used in winding,the black and white connector Thank you and 73s.

Another banger, Ape. Is the toe-roid secured to the box somehow?

I’ve been wondering how a 4:1 unun would work with an ofcd since I heard you briefly mentioned it in another video you did. Thank you for clarifying that. I’m hopefully going to be taking my general exam in a few weeks and this was the one I wanted to build for it. Curious if you would know though what length of wire would be preferable for making an ofcd that would have resonance on 60m? We have AUXCOMM nets here in Georgia on 60 meters and I’d love to get onto that once I pass the general. A simple resonant dipole would work yes, but I like the idea of having a multiband antenna even if it’s a compromise.

Need one of these for a Rybakov antenna

Mr. Ape, what kind of RF bandwidth did you get out of that unun? Very nice!

Would this work for a receive loop on ground?

CaHR OCFD antenna design? Or a CaHR unun kit? 🤔 My shack antenna is an 80-10 OCFD. Tunable to all in that range except 60m. A portable 40-10 OCFD would be nice. SO-239, of course.

why would you use a mix 52 toroid over a 43 mix?

Should also work for a full wave Loop

nice UNUN for go kit. I will make more later. out of ferrite cores. want to make a 9:1 as well. even a 64:1 for 160 meters. the 3 I made now work great ! FT 240-43 in 49:1 with cap. runs 250 watt all day . the 2 stack of type 61 in 49:1 3KV cap 100 PF . runs 500 watt FT8 no problem on 10/12 maybe 6 meters. the 2 stack of FT 240-43 runs same power and better for 80/40/20 /17 /15 meters, found QRO on 10/11/12/6 meters type 61 FT 240 runs cooler. thermal cameral tested . had slight better SWR band with on them bands . I have the same binding post. think I will use on 9:1 for my go kit. need toroid and box. have the rest. want to make a 64:1 as well. 4:1 will work for loop on ground antenna as well. I want a bunch to play with for all day POTA . 73's

I can only count to 4.

What you have at best is a 4:1 transformer or a voltage unun. Voltage baluns/ununs are fine for balanced mixers etc but what we want for an antenna is to reduce common mode currents. One cannot make a 4:1 current balun on a single core. Even then, without making a VNA measurement across the frequencies of interest of S21 dB or preferably an S11 R+/-JX plot, you don't know what you have. Dale W4OP

When we look at things like impedance ratio, we look at the equation Impedance ratio=the square of the turns ratio. If we want to see the resistive losses in a transmission line, we can calculate the square of the current multiplied by the measured resistance. So the impedance ratio is pertinent to the matching the antenna to the transmission line. If we vary from that calculated value too far, our efficiency will suffer. If our calculated losses are too high, our efficiency drops to unacceptable levels. There are a multitude of gain calculation that our antenna model simulators do for us. But nowhere in actual engineering books I have seen are there any calculations for balanceness. It's obvious that the OCFD is less unbalanced than the EFHW. So how do we calculate this? How do we adjust our lesser unbalanced designs for the more unbalanced designs? If a coax is unbalanced, how unbalanced is it? Where is the unbalanceness specification? How can we calculate it from given data? Serious question.

Nice little build, Son. Apart from the crooked binding posts.😊

Tell them OCD boys it's not crooked, it's unbalanced.

"whatever you call" .... hundreds of time .... please stop that nonsens!