Note: Prices quoted are Canadian dollars (muliply by 0.7 for US). Web site is radioshack.ca -- much smaller site than radioshack.com

RF stands for radio frequency. Generally RF signals are sent through coaxial cable, so the terms RF and coax are often used interchangeably. Coaxiale cable is that quarter-inch round cable, usually black, biege, or white. It is well-insulated, and of high enough power that it can run for long distances (10-100 feet) without unacceptable signal loss.

Really old TVs will only accept input from from an aerial (i.e. rabbit ears). You can use one of (these-300-ohm antenna to 75-ohm coax cable) to connect a coax cable to the screws made for attaching an aerial, but you'll get a bit of interferance from the two inches of exposed wire (which acts like tiny two-inch rabbit-ears).

Slightly more modern is direct cable input. (little threaded socket on the TV where you screw on the quarter inch thick coax-cable) To attach a DVD player to a direct cable input, use one of (these-rf modulator). (Then the VCR plugs into the RF modulator's coax socket, and the DVD plugs into the RF modulator's line input sockets. Most modulator's output is automatic: turn off the DVD to switch modulator's output to VCR.)

Slightly more modern still is line input (RCA plugs). (three little sockets with one hole each, coloured yellow, red and white: the red and white are for audio, the yellow is for video) A good way to switch between your VCR and DVD is to use one of these-3-WAY STEREO AUDIO/VIDEO SELECTOR Many more expensive TVs have built-in video selectors. They will usually be labeled video 1, video 2, etc. Selecting which TV input to view may be tricky; consult your owners manual.

Slightly more modern still is S-Video input. (circular socket with six little holes and one little vertical slot, looks it would accept the plug on your standard PC mouse or keyboard). Audio is still transmitted through two RCA lines (red and white).

Slightly more modern still is component-video input (similar to line input, except there are three lines for the video). Audio is still transmitted through two RCA lines (red and white).

Most modern of all are various digital inputs. Audio can be sent digitally over at least three different types of connectors. Video can probably be sent digitally between some system's components, but in general, I don't know anything about the digital stuff.

Although it is older, coax usually gives a clearer video signal than line input (RCA plugs), unless the connection is short with a well-insulated connector. Even component video doesn't look as sharp as coax if the connectors are really poor (i.e. the free connectors supplied with a US$30. DVD player). If you want a good picure, you need good connectors (at least US$10 per line or more). That probably applies to selector boxes as well, although I haven't experimented with cheap/expensive boxes.

When playing, VCRs usually sent out a picture on channel 3 of their coax outputs. VCRs will often have "line" outputs (yellow/red/white). Use these if you have reasonable quality connectors and the right sockets on your TV. If a VCR has "line" inputs as well, these must be selected (different for each VCR) as the input source for the VCR to rebroadcast them. Although you can connect your DVD to the "line" inputs of the VCR, since it is usually impossible to copy a DVD onto VHS tape, you're probably better off with a video selector box (switching your TVs input between VCR and DVD) than you are running your DVD in series through your VCR into your TV. Moreover, many VCRs won't accept and rebroadcast copy-protected signals, like those coming from a DVD player; some very high quality VCRs will give you nothing but a blue screen when you try to watch a DVD player's output through the VCRs line inputs.

To copy DVDs, you need a fast computer with a DVD-RW drive, about 30 GB of free hard drive space, and a program like DVD XCopy XPress It's illegal unless you own the DVD.