Best Antenna for 75MHz radios. The required antenna length for a 75 MHz radio is about 31". If you roll the excess up inside the model the transmitte can "see" it if the model is plastic or wood, but if it is in a metal model or has a lot of matelic paint on the plastic that will cut down on the reception. Our small antenna is "BASE TUNED" like a real "CB" antenna to see the full 75MHz signal. This antenna will make a big difference!