Expert: Cleggsan - 7/17/2009

Question
I am installing a radio inside my boat, i need the antenna to be mounted 16 feet away. I bought male and female connectors from radio shack but I do not know what wire I need to make an antenna extension cord. Can I use coax that is used in cable TV ? If not, then what can I use.

Answer
Yes, you need what the electronic store calls RG59/u cable.

You can buy it at many places. It comes in bulk as well as standard lengths with connectors already on the ends, or stripped leads.

You should use the right connectors as well as they are an important part of the impedance and standing wave reflections on the cable.

Your antenna should be, in this case, a 75 ohm unit.  Some antennas are 300 ohm; if so you will need a transformer at the receiver end to convert it to 75 ohm input.  (Unless the receiver has screw terminals for the antenna - which is the old way of doing it and they are 300 ohm input and use the twin lead flat cable).

If you are confused, ask me further questions. If you do, I must know the make and model of the radio unit - that way I can learn what the specifications are for it.

C

http://www.summitsource.com/images/products/PE7506.jpg

The above is a 75 ohm to 300 ohm transformer.