What you mean by narrower is the vhf/uhf thing I mentioned. The higher the frequency,uhf, the more line of sight you must be. For your area, the digital channels must have switched. If the stations transmit both, the digital is usually powered reduced to cut down on interference. A poor antenna was not such a big deal with analog if you could put up with poor picture, digital is far less accomadating.
I would suggest you invest in a quality antenna, there are omnidirctional ones that will allow traveling if you are close enough to the signal. directional antenna for further distance but you will have trouble keeping it aimed while moving.
With the dtv transistion, there are tons of websites about this.
AntennaWeb is a good source.