Original Publication Date: 1964-Jun-01
Included in the Prior Art Database: 2005-Mar-07
AbstractThis is a selective audio amplifier with a high Q which equals two hundred.
This is a selective audio amplifier with a high Q which equals two hundred.
The tuned output network has a coil and a capacitor. For low resonance frequencies, a large capacitor is needed. This capacitor is variable for tuning the network.
The large variable capacitor is obtained by using the input capacity of a variable gain amplifier, fed back with a capacitor C. The input capacity equals (1 + the absolute value of A )C and is adjusted by varying the amplification factor the absolute value of A.