The QRPer Board

Posted: **Sun Feb 09, 2025 8:40 pm**

I am looking to build (yet another) 4:1 unun for a Rybakov antenna. Looking online, I see about half of the articles recommend a TX-2 toroid, and half recommend a TX-43.
I would think that the TX-2 toroid wouldn't be great for the hgher bands - if a powdered toroid were needed I would have expected a TX-6. Anyway, I'm wondering if there is any reason to choose the powdered toroid over the 43?

Mike, KL7MJ

Posted: **Tue Mar 25, 2025 5:17 pm**

KL7MJ wrote: ↑Sun Feb 09, 2025 8:40 pm I am looking to build (yet another) 4:1 unun for a Rybakov antenna. Looking online, I see about half of the articles recommend a TX-2 toroid, and half recommend a TX-43.
I would think that the TX-2 toroid wouldn't be great for the hgher bands - if a powdered toroid were needed I would have expected a TX-6. Anyway, I'm wondering if there is any reason to choose the powdered toroid over the 43?

Mike, KL7MJ

ok. since nobody replied I guess I may try; start from this

https://slideplayer.com/slide/10775160/ ... +Balun.jpg

which shows the (subtle) difference between a BalUn and a UnUn, then see this

https://vk6ysf.com/balun_4-1.htm

for some ideas about the 4:1 and its core material

HTH

Posted: **Wed Mar 26, 2025 10:31 pm**

further infos

https://wb3gck.com/2018/12/09/revisitin ... -vertical/

and add this

https://www.g4akc.co.uk/ground-tuning-units-gtus/

between the antenna and the ground stake or the radials

The QRPer Board

Which toroid for 4:1 unun?

Which toroid for 4:1 unun?

Re: Which toroid for 4:1 unun?

Re: Which toroid for 4:1 unun?