A channelizing receiver is provided with a plurality of channel receivers for monitoring respective segments of a frequency band being monitored by the channelizing receiver. A continuous hinge is connected to the panel along substantially the full length of a first side thereof. The voltage switching unit has a plurality of high voltage distributing portions branching the voltage supplied to the switching elements into one or more voltages of differing voltage levels, and supplying the branch voltages and the initially supplied voltage to the respective developer units. The method includes generating a signal indicating that a first value of the physical property is associated with the first spectrum, the first value being determined using the physical property value associated with the identified previously recorded spectrum in the database. The door may be pivoted between an open position and a closed position over the front.