We can modify your ZX81 to use composite video instead of RF (aerial). Because this modification involves fitting a "ZXVid" there are no external changes to your ZX81 - you just plug in the supplied phono lead to your ZX81 and your television's "video in" port.
Just send us your ZX81 on its own and for the first time it will display correctly on an LCD television.
We will also change the electrolytic capacitors, as these parts have mostly aged and may now cause interference.