Complex sentence: RF modulators produce a relatively poor picture, as image quality is lost during both the modulation from the source device, and the demodulation in the television, but the aerial connector is standard on all TV sets, even very old ones.
Split into simpler sentences: RF modulators produce a relatively poor picture, as image quality is lost during both the modulation from the source device, and demodulation in the television. However, the aerial connector is standard on all TV sets, even very old ones.