Question
Why should DC power for a 100-watt HF transceiver not be supplied by a vehicle’s auxiliary power socket?
Answer Options
- A) The socket is not wired with an RF-shielded power cable
- B) The socket’s wiring may be inadequate for the current drawn by the transceiver
- C) The DC polarity of the socket is reversed from the polarity of modern HF transceivers
- D) Drawing more than 50 watts from this socket could cause the engine to overheat
Correct Answer: B
Explanation
Vehicle auxiliary power sockets (often called cigarette lighter sockets) are designed to handle low-current accessories, typically rated for 10 to 15 amperes. A 100-watt HF transceiver, however, can draw 20 to 25 amperes on voice peaks.
Therefore, the primary reason the auxiliary power socket should not be used is that the socket’s wiring may be inadequate for the current drawn by the transceiver. Attempting to draw excessive current can overheat the wiring, melt the fuse, or even cause a fire. The radio must be wired directly to the battery with heavy-gauge wire and a proper fuse.
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