One would assume that with the wide array of adapters, connectors and modulators available to the home audio enthusiast, converting a coaxial audio/video signal to RCA outputs would be an easy task. Unfortunately, the equipment to do this is not often readily available. Fortunately, there is an easy fix, and it might put your aging VCR to good use.
Determine your desired method. Using a VCR is the easiest method, and chances are you have one gathering dust in a closet somewhere. If you don't, seek out a Coaxial-to-RCA modulator, a device that's not always easy to find. RCA-to-Coaxial modulators are readily available, but unless they work in reverse, won't serve this purpose. Check with your local electronics store or radio shack.
Connect the coaxial cable to the back of the VCR or modulator. Find the "coaxial input" and connect the coaxial cable from your A/V source to it. Spin the nut to tighten.
Connect the RCA cable to the VCR or modulator. Find the "RCA output" connectors, or look for the red, white and yellow jacks labeled "out". Connect one end of the RCA cable, matching the colors.
Connect the RCA cable to your TV or other A/V source. Find the RCA input jacks on your TV or other source and connect the other end of the RCA cable to it, matching the colors.
Turn on your VCR. Making sure it's plugged in, power on your VCR. If your VCR has a "TV/video" switch, change it to "TV".
Turn on your TV or other source and test the connection. Now that you have everything hooked up, test the connection. Make sure your TV or source is displaying the proper input. If you are receiving a TV signal through the coaxial cable, change channels with your VCR's TV tuner.
Things You'll Need
VCR (post 1982) or Coaxial-to-RCA modulator
Most VCRs can perform this function, but some may not. You are essentially routing the coaxial signal into the VCR, which separates and converts it to higher-quality RCA outputs. Check with your VCR's documentation if you have trouble.