[Sideband]

You can get away with no sig gen for MW alignment using broadcast stations. However you can't do a very good job on FM without at least a signal generator. Some discriminator circuits can be tricky to balance even with the correct gear but without it.....! A lot of twiddling MAY get it acceptable but it will never be right. It does sound as if the discriminator is a bit off but I've never tried to balance one without a sig genny.