Off Center Fed (OCF) Antennas Mix 43 Store / Mix 43 Ring - Mix 43 RFI Range: 25-300 MHz Ring - Mix 43 RFI Range: 25-300 MHz Snap On - Mix 43 - RFI Range 25-300 MHz Snap On - Mix 43 - RFI Range 25-300 MHz Slip On - Mix 43 - RFI Range 20-300 MHz Slip On - Mix 43 - RFI Range 20-300 MHz OCF antennas are very convenient as they will allow multiple bands of operation with a simple wire antenna which is fed off center with a 4:1 OCF Current balun with built in feed line choke,