| 摘要 |
<p>The circuit is for frequency tuning a radio aerial onto a determined valve amongst a multiplicity of other valves. That is by adjustment of inductance or capacitance. The circuit uses a number or elementary capacitors and inductances. It also has means for switching in and out these capacitors and inductances. This is to give the aerial a particular tuning valve for a determined frequency. The inductances and capacitors are mounted so as to provide equal equidistant inductance and capacitive valves. The method of automatically adjusting the aerial impedance using these inductances and capacitances as follows. Pairs of digital inductance and capacitance values are associated in succession with the aerial. A comparison is made, by means of a discriminator, of a magnitude corresp. to the resultant impedance and a reference magnitude. When the output of the discriminator is less than a predetermined valve the sequence is stopped.</p> |
