Hello folks…brand new here on the forum. I am looking to DIY a 49:1 Balun (2450 ohms to 50 ohms) for an End Fed Half Wave antenna for 3 -14 MHz. I have seen a few YouTube vids showing a Toroid Ferrite Core that is roughly 3.5" O.D., roughly 2.5" I.D. and roughly 0.5" thick. I am hoping someone here would be familiar with the specific core I would need and provide a part number please. Thank you for any helpful input.