Piggie

The old aural carrier on Ch6 was 87.75 MHz, and the top of the channel was and still is 88 MHz. There is no guard band between Ch6 and FM, and actually they overlap.

Ch200 on FM is 87.9 MHz inside the Channel 6 spectrum. Granted there are not a lot of FM stations on channel 200 (why they started counting as 200 for FM channels I don't know).

Even Ch 201 is barely outside the band at 88.1 MHz, with it's sidebands legally touching the edge of the Ch 6 TV.

But if you live near any FM between 88 and 92 MHz range, and there is a Ch 6 TV farther away, yes, it become a problem. You will get herringbone on the screen of an analog (now history). But that would seriously affect reception of DTV.

So even though an FM station is assigned 200 KHz wide channel, that doesn't mean 100% of the energy stays inside that 200 KHz. It's simply not possible to built a filter that performs like that. It only has to be a certain db down from the main carrier at 100 KHz either side of the carrier. But if you live within a mile or so of a 100KW FM, then say the spurious radiation outside the channel is down 60 db, which is enormous, is still 1/10th of a watt or 100 milliwatts. This is the same amount of power as an FM microphone uses. And 60 db down is down in the noise on most analyzers or close to the noise. Yet 100 milliwatts at close range will wipe out DTV. That is just like a cell phone next to the TV causing problems.

So yes, they interfere and have to be considered.