Best 4:1 UnUn for Ham Radio Antennas? 

Thanks Don, that’s why I’m here 🤨

Hey Mike, we liked the testing. Now we just need to get them shipped 👀

Thanks for watching 👍

Awesome Pat, thanks for watching 👍

I try! Thanks BA 👍

Thanks for watching 👍

Thanks

Thanks 👍

Thanks for watching 👍

Haha, it’s not easy!

That might be true

These are type 52 powdered iron and not the mix 52 ferrites, I think you are recognizing that. We, along with others have used these is a 25’ vertical antenna configuration with four 17’ ground radials with success from 40-10m. I don’t recall anyone trying on 6m. We did use a tuner but with that antenna configuration it’s to be expected. Admittedly, I was surprised at the results.

Me too!

Hey less, it is a good idea to use the 1:1, thanks for the comment 👍

Hey Subramanian. Thanks for the post, I did read the spec sheet but for this particular build we did test a few different Toroids and much to my surprise this one did particularly well.

@TheSmokinApe OK Ape. Thanks for responding. But this core can be used in MW frequencies; it can be used as high as 1 MHz or 1.5 MHz max. That's all. You may get deceived sometimes with the nanoVNA. In the real world, it would be useless. Instead, you can test mix 2 or mix 6. I believe you might have tested them already 🤔 De VU2RZA

It is...

Glad you liked it Bill 👍

It depends on the application but many folks use the ferrite mix 52 for 80 and 160 👍

I believe the gauge of the wire is the biggest criteria.

Hey Doug, the size and composition of the core are the two most critical factors. When these cores get hot they loss magnetic properties which stops their ability to transform impedance. More power = more heat.

Hey Hollywood, I just emailed over the specs...

You could. But you would need to know the impedance of the antenna and then adjust accordingly 👍

Here’s how we picked the core, we also did other tests. Compared: 4:1 UnUn's for Ham Radio Antennas ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-lYhY3Huj7pM.html Also, we did similar for the number of windings.

52 Powder Iron

Your avatar looks weird without a hat....

@@Ezzell_ it does, but I can't remember where I made it to update it.

@@Ezzell_ it does, but I can't remember where I made it to update it.

Green = more faster

I think there is much debate over the dual Guanella vs the Ruthoff and Guanella current hybrid. I can do a video, at some point on the dual Guanella

Yeah, not a bad idea

Hey Robert! This is for a vertical ground plane type antenna, the CaHRtenna Poseidon

@@TheSmokinApe I was thinking that. love the test video's that dropped lately . with the cores back to back. put 50 ohm dummy load on it and you can do power test for core heating.

I actually have a video like that planned 👍

Hi Robert, let me make some clarifications. An OCF, off-center fed dipole is an unbalanced antenna. You are using a half lambda wire and feed it in the center because the feed point impedance is low in the range of 50-75 ohms and is suitable for a coaxial cable. This center fed dipole is resonant (on only one frequency) and can be used for a single band only. If you want to work on multiple bands, you have to find out a point on the half lambda wire that would remain with a fairly fixed impedance. It can be 1/3rd or 1/4th from any one extreme end of the half lambda wire; it would be around 200-300 ohms depending on other factors especially like the feed point height above the ground. So, a 4 to1 or 6 to1 transformation to the standard 50 ohm coaxial cable is needed. Here, in this video Ape demonstrates a 4 to 1 Ruthrof voltage BalUn. The demerit of this design (apart from the choice of wrong core mix) is that it won't provide any CMC, common mode current suppression. Yes, in any OCF, you will be expecting the CMC problem. You can mitigate in two ways. 1. The Ruthrof voltage BalUn must be followed by a 1 to 1 CMC choke. 2. You can go for a 4 to 1 Guenella current BalUn using two ferrite cores of sufficient size for the power to be handled. Don't get tempted to use a single core 4 to 1 BalUn. Just for completion: ferrite cores are termed like FT82-61. Iron powder cores are termed like T200-2. When you intend to use more than 600w, you should go for Teflon wires of sufficient gauge; don't use enameled copper wire (magnet wire) I think this helps. De VU2RZA

@@subramanianr7206 what I made was a mono band off center fed. only for 10,11,12 meters buy folding extra wire and wrapping it around. adjusting match. not a high power antenna. just one FT 240-61 core I had. and my coax feed has choke at end wear it goes to Balun. everything made with Walmart speaker wire . just testing. I got tune on CB CH 20 at 1.2 VSWR . just speaker wire and tape. all tape on DX commander 10 meter pole. hears the skip like crazy. I will use better wire next time. I did do a 2 stack wound 10 AWG 49:1 and handles 1 KW tested . 400 watt FT8 hours cores slay slightly warm . no rise in SWR . I have thermal imaging camera . Flair . 73's

This is for the new Poseidon CaHRtenna 👍

Not sure about the symbol. Just one roid for 40-6 👍

It's not for a EFHW, its for a short vertical ground plane.

Electronic parts distributors like DigiKey, Mouser, Newark, etc.... If your looking for ones specifically for amateur radio related uses then Palomar Engineers is a good source of known good quality cores.

JPMSupply.com is good 👍

@@TheSmokinApe I appreciate that. I'll check them out.

They are t130 type 52 powered iron 👍

@@TheSmokinApegiven that, I'm blown away that they work as well as they do at HF!

@@hamradioexperience I was a little surprised myself

@@TheSmokinApeI'll have to do some more testing. I was literally just told they MAY be of LIMITED use on HF. They seemed great from your video. Other than at sub-80m. I might try to duplicate your results, then copy with a -43 mix. Might be interesting...

@@hamradioexperience I’d be interested to hear what you find. We did compare them to multiple core and then decided to go with this one. Thanks for watching HRE 👍

Yup, balun=Balanced to unbalanced connection.

K4AX is correct.

52 👍

Thanks for the math BDRFI, it’s helpful 👍