nads:it depends on the TV. some have a scart in and out so you can record from the built in box.
I agree - if you look in the back of the TV manual (it's normally in the back you understand) there will be a bit of techno speak about the AV1 and AV2 sockets or whatever the TV is blessed with.
The key phrase you are looking for is video out. If there is a SCART AV2 socket this will be the most likely to have a bi-directional video and audio connection.
Most DVD recorders and PVR's have a suitable AV in for external sources.
For example I have an old Lite-On DVD/HDD recorder with analogue tuner hooked up the the SCART AV2 socket of my 32 in Panasonic LCD and I can record programmes off screen. The drawback of course is that the TV has to be on.