Why are heavy-gauge wires used for a 100-watt transceiver's DC power connection?

A typical 100-watt transceiver operating on a 12-volt DC supply will draw about 20 amperes or more of current when transmitting. Every wire has a certain amount of electrical resistance based on its thickness and length. According to Ohm's Law, pushing a high current through a thin wire with higher resistance results in a significant voltage drop along the wire. If the voltage drops too much, the transceiver will not function correctly or transmit cleanly. Using heavy-gauge (thicker) wire reduces the resistance of the connection, thereby minimizing the voltage drop and ensuring the radio receives the full voltage it needs. Wire gauge does not prevent electrical shock, especially at safe 12-volt DC levels, nor does it filter ripple.