Thanks for the link to these at that great price. I did order two of them.Here is one of the best prices I've seen on the FT-240-31 ferrite core at $6 each. Every year at Dayton I stop by Howard's table and get about $200 in ferrite products. Fair-Rite 2.4″ Toroid Core - Pro Audio Engineering
If your going to roll your own make two and put the second one at the radio end. You can sometimes lower the noise level into your receiver doing this.