So you want a Timex Sinclair 1000 but need to hook it up to a modern TV (in the U.S.). Well, there's an RCA/phono jack on it, so you can just hook it up to the composite video connection on the TV, right? Not so fast! Phono plugs were used for many RF applications in the 80's. The video from the TS1000 is an RF signal that we would expect to see from a modern CATV/antenna cable (coax with an 'F' connector). We need an adapter to plug it into the CATV/antenna jack of a modern TV. The adapters provided with the TS1000 won't work. Fortunately, you can buy the correct 'F'/RCA adapter from RadioShack for less than $4. This adapter plugs into the back of the TS1000 and you can use a standard CATV/coax patch cable to connect from the adapter to the TV. Then set the TV to channel 2 or 3 depending on the position of the channel selection switch at the bottom of the TS1000.
You can modify the TS1000 to output composite video, but the RF signal is good enough for most purposes.