1. FT-817 CAT interface - http://speakyssb.blogspot.com/search/label/FT-817
2. SDR-SERVER List - http://www.ve7ed.com/extdocs/SDR.html
3. Online Toroid Multi Calculator - http://toroids.info/
4. RF - Homebrewing a 6 Meter Yagi - https://pdf4pro.com/view/rf-homebrewing-a-6-meter-yagi-1507f.html
5. End Fed Halfwave Antenna And Matching Unit - http://www.n0lx.com/efhwa.html