REFLEX_RADIO_RECEIVER

Published:2009/7/17 2:28:00 Author:Jessie | From:SeekIC

The RF signal is passed from the antenna through C1 to the tuned circuit made up of L1 and C2．Oneend of L2 feeds the RF signal to the base of Q1 for amplification and the other end ties to the junction ofR1and R2 to supply bias to the transistor．A 0.02-μF capaotor，C3，places the“D”end of L1 at RE ground. The amplified RF signal is fed through C6 to a two-diode doubler/rectifier circuit and then on to thevolume control，R6．The wtper of R6 feeds the detected audio signal through C9 to the junction of R1，R2，and the“D”end of u．The“D”end of L2 is at RF ground，but not AF ground，allowing the AF signal tobe passed through L2 to the base of Q1 for amplification. The junction of the 2.5-mH choke and T1 is placed at RF ground through C5. The amplified audio is fed from this junction to the mput ofthe 386 audioamplifier，U1，to drive the 4 8-Ω speaker．The single transistor has performed a dual duty by amplifying the RF and AM signals at the same time．



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