RG-59 72 Ohm cable
Do not run RG-58 or RG-8X from each antenna to a T-connector at the back of their radio. You should not use 50 ohm coax on a ground plane dependent dual antenna installation. It MUST be 72 ohm RG-59 type coax. These flawed installs can be misleading because SWR tests can show exceptionally low SWR, making the installer think that all is well. However, the impedance of the antenna system does not match the requirements of the radio and therefore, the output power of the radio is greatly reduced. In several tests, we found that a 4-watt radio would only generate 1.75 watts of output power that is the equivalent of having an SWR reading that exceeds 6.0:1.