I have a PCTEL MWV13222HDS which is supposed to be a wideband 1/2 wave gain VHF antenna with NMO mount, however when I received the antenna it has a whip that is 49 inches long, it does have the spring, the base shows 132-174mhz, the cutting directions with it say for 148-174 MHz the antenna should be cut to 28 1/4" with the spring and 31 1/4" without the spring. I left the whip at 49" and placed it directly on the base. When I had the spring on it seems way too long, but the inches given in the cutting chart do not seem accurate. Does anyone have a correct cutting chart for this model with the spring and without, centered at 155 MHz?