Patent ID: 6628931
Filing Date: 2003-09-30
Classification: H04B

Abstract:
A shortwave receiver adapted to be used with an antenna module having:a loop antenna; an auxiliary tuning coil; a variable capacity diode connected in parallel with the loop antenna to form a tuning circuit for high frequency tuning operations; and a high frequency amplifier for receiving a signal selected by said tuning circuit, said shortwave receiver comprising: a receiving circuit for receiving a shortwave broadcast signal output from said antenna module; a formation circuit for forming a tuning voltage to be applied to said variable capacity diode; and a jack, wherein when using said antenna module, said formation circuit is controlled corresponding to a reception frequency of said receiving circuit so as to modify said tuning voltage to accommodate a reception band of the shortwave broadcast signal received by said receiving circuit and cause said tuning voltage to be output from said jack and applied to said variable capacity diode; and an antenna adapter for detecting a band selecting voltage of said shortwave receiver and producing a control voltage therefrom fed to said antenna module for connecting said auxiliary tuning coil to said loop antenna and variable capacity diode depending upon a selected band.