Intruder makes a good point...
Yes, Intruder makes an excellent point! The same thing happens when you tune in an ILS on your NAV receiver. The localizer is VHF (and that's the frequency you're tuning "on your radio dial"), but the glide slope is UHF, and the 'frequency pair' is a standard match...so, your glide slope receiver is automatically tuned.
In other words, anytime you tune in (let's say, for example) 109.5 on your NAV receiver, you're automatically tuning XXXX (whatever the corresponding UHF frequency is) in your glide slope receiver. The pairing list is published somewhere. I'd have to look to find it. But, it's a standard pairing.
Same for the VOR situation...
PantLoad