Patent ID: 7801497
Filing Date: 2010-09-21
Classification: H04H

Abstract:
1. A radio modulator apparatus, having a radio band scan function, comprising: a frequency selectable RF signal transmitter; a switch that couples said RF signal to an antenna; a demodulator coupled to mix a received antenna signal with said RF signal to produce an indicia of signal strength at the receive frequency resulting from the mix; a channel memory coupled to store plural indicia of signal strength values corresponding to plural receive frequencies; a controller coupled to said transmitter, said switch, said channel memory, and a display, and wherein said controller enables the frequency scan function by decoupling said switch, tuning said transmitter RF signal to plural frequencies, thereby causing said demodulator to receive plural receive frequencies within the radio band, and storing the resultant plural corresponding indicia of signal strength in said channel memory, and said controller compares said stored plural indicia of signal strength to select a present transmit frequency that has a low signal interfering level, couples said transmitter to said antenna, tunes said RF signal to said present transmit frequency, and displays said present transmit frequency on said display.