Does location have to be set in Sentinel for conventional frequencies being programmed?
Location & range only have to be set if you are adding the frequencies (or a trunked system) to a Favorites list that you have set to use Location Control. If you are not using location control on the list you are adding these to, then you do not need to have location details in addition to the frequency details. They would be scanned along with anything else in that list.
If you were to turn on location control for a list that contained systems & frequencies without location information, the scanner would treat the blank details as zero degrees for both latitude & longitude, which would be in the Atlantic Ocean off the coast of Africa. Needless to say, that would be out of range, so they would not be scanned.