The DK7ZB 28 to 50 ohm coaxial matching transformer
We’re not going to republish excellent already published materials from known experts.
Authors such as DK7ZB need no introduction, so we’ll link directly to the page here. For HF you’d normally consider a hairpin match, but at VHF and UHF this fully symmetrical solution is king.
You can find all the info you need to create a world-beating 28 to 50 ohm match with ease.
For a 28 to 50 ohms impedance transformation, 2 equal lengths of 75 ohm coaxial cables are used. Link below.