I am having trouble with the TV reception in my RV. I have been told it is either the antenna head or the powered wall receptacle. How do I tell which is the bad part, other than buying and replacing each part until it works?
Mark (Islip, NY)
Mark, the 12-volt power supply of the TV antenna actually sends 12-volts to the power head in the antenna. First, be sure the power supply is turned off; never connect or disconnect the coaxial cable with the power supply turned on. Up on the roof, disconnect the cable at the antenna head. With the power supply turned back on you should be able to measure 12-volts DC between the center conductor and the braided shield on the coaxial cable. If 12-volts DC is not present on the coax, turn the power supply back off and remove the power supply and receptacle from the cabinet to gain access to all the connections. Disconnect the coax lead going to the antenna head and turn the power supply back on. If no voltage is present at the power supply output connection, check the incoming voltage to the power supply. If adequate voltage is coming into the power supply, but no voltage is present at the power supply connection leading to the antenna head, replace the antenna power supply. If you can measure voltage at the connection on the power supply for the antenna head, either the coaxial cable is broken or the antenna head itself is faulty. Turn the power supply back off. Obtain a length of coaxial cable and bypass the existing cable. Run the replacement coax from the output of the power supply, out a window and up to the antenna head. Turn the power supply back on once more. If you have amplified and improved television reception, the existing coaxial cable has an open in the conductor which mandates replacement. If the reception is not improved, replace the antenna head. When replacing the coax, it will be necessary to route the cable from the cabinet which contain the power supply up through the roof and to the antenna head….or you’ll have to leave that window open all the time! And be sure to properly seal any cables penetrating the roof.