Things You'll Need
Instructions
Provide adequate ventilation around the body unit if the radio becomes excessively hot, or cuts out. Some long transmissions at 50 watts will create significant heat. Move the body away from heater ducts and other after-market electronics like an amplifier that also creates heat. Don't place shopping bags, clothing or other objects on the radio body. Avoid using the radio in environments where the ambient temperature reaches 140 degrees F. or more.
Use high-quality coaxial cable between the Yaesu FT-8900 and the antenna if transmission quality is poor. Remember that a 25-foot-long cable with .50dB of loss at 29 MHz will have 6dB or more of loss at 446 MHz.
Connect the supplied power cable directly to the vehicle's battery to avoid voltage drops that can cause transmission problems. The included cable has a 15 fast-blow fuse fitted in-line, so you don't need to worry about surges. Red should connect to the positive and black to the negative on the battery. Use color-coded No. 12 AWG wire if you need to extend the included cable.
Check the rear connections if you continue to have problems. The antenna should be tightly screwed onto the antenna jack, labeled "Antenna," external speakers plug into "Ext Sp" and the six-pin mini-DIN connector is an interface for a packet node controller labeled "Data."