The JVC may not have an RF modulator built in which is what you require. Check the manual / menus for a modulator on / off setting. If it has one there is probably a channel selection setting as well. Just choose a channel that is unused in your area, i.e. away from your local transmitter's channels.
If the JVC doesn't have a modulator then you would need an external one, something like this
You could also use a VHS machine if you have one lying about