Separation

A separation value of -50dB is possible on VHF/FM. This is a Hitachi FT-5500 MkII set to wide IF and RF.

WHAT IT MEANS

VHF/FM tuners typically have channel separation values of 40dB in the mid-band and around 35dB at 10kHz. This is more than enough for the perception of stereo, even if it is a lot less than that of other sources except LP, which manages around 30dB at best.

The residual or crosstalk signal can be heavily distorted and this does not help sound quality if severe.

Leader 3216 Standard Signal Generator produces stereo.

HOW WE MEASURE IT

We use the low distortion internal generator of our Leader 3216 Standard Signal Generator to modulate Left and then Right channels, whilst working in stereo with the pilot tone on. The level of the crosstalk signal is measured with a Rohde & Schwarz UPL analyser, in narrow band mode (third octave) to avoid interference from noise and pilot tone, etc.