Ferrite Toroid FT240-31

For use in baluns and line-isolators. More than enough for UK legal power so perfect for your QRO balun project. 8 turns of RG58/RG316 (400w SSB) or RG142 (1kW CW/Digi) make a great "resistive" balun/choke for 3.5MHz-30MHz.  The 31-mix is perfect for an all of HF Choke/Balun and our own legal-limit baluns and chokes use this 31-mix core and RG142 for a robust, high-powered solution.

• Use: Bands 80m to 10m
• Size: 60.0x35.5x12.7mm, 2.4x1.4x0.5in

Toroid sizes/types are easy to ID, the "240" translates to 2.4" (diameter) and the "31" is the ferrite mixture. What type do you need? 61 is used in the G3TXQ CobWebb balun, 43 is good from 7MHz and up (and a good general-purpose 7-30MHz solution) while 31 is better if you use the lower HF bands. Remember, you can stack the cores for increased choking and power-handling. As always, ratings need to factor in the aerial (SWR) match and duty-cycle.  See our video on Ferrite Toroids and Baluns here...

We also sell a snap-on 31-mix ferrite, known as the Problem Solver...