The main use of an RCA to coaxial converter is to carry a signal from a device which uses the three-cable RCA system to a television set which only has a socket for a coaxial cable, such as one which runs from an aerial. This can be particularly useful when you have a newer device such as a games console or DVD player and want to run it on an older television set. You might also need a converter if you want to run cabling from a cable or satellite box to a second TV set which only has a coaxial input.
It’s important to note that in this context, coaxial doesn’t refer to the audio cables commonly used for connecting DVD players to surround systems. The term coaxial is sometimes used to distinguish between audio cables which use wire and those which use an optical connection. However, here we are talking about cabling which carries both video and audio signals.
While it is possible to make an RCA to coaxial converter simply by producing a physical adapter to make the cables fit the socket, this won’t usually be enough to get the picture on to the TV set. That’s because TVs receiving a signal through a coaxial cable expect it to use a particular system which is designed to carry multiple TV channels from an aerial through a single cable. The answer is an RF modulator, a small device which not only physically converts the cabling, but alters the signal to the required format.
You don’t necessarily need a dedicated RCA to coaxial converter as you can achieve the same effect by routing the signal through other equipment. One way to do it is through a newer VCR which has RCA inputs. You can plug your equipment, such as a cable box, into these inputs, set your VCR to the appropriate channel, then view the picture on the video channel of your TV set.
If you are thinking of using an RCA to coaxial converter, don’t forget that it will make little or no difference to the picture or sound quality on your television. An RF cable to a TV can only carry a mono signal and provides the worst quality picture of any cabling in common use. You may well find that buying a new TV set with modern inputs makes better financial sense as it means the money you pay for DVDs or cable television isn’t wasted by not getting the full picture and sound quality.