Gearmotor and Monobander Antenna Systems
Click on the photo for a closer look.....
The optimum sized coil that will give the best performance for a high performance gearmotor mobile antenna, needs to be 3" OD, wound with 12 gauge wire, at 6tpi (turns per inch)
The gearmotor antenna that resides on my mobile (seen above) meets these parameters.
The 10-60 meter antenna used with my manpack, also was built using the dimensions as described here.