The TDA2002 can draw considerable current when driven hard. A well filtered regulated power supply of at least one amp capacity should be used to power the receiver.
If distortion is heard in the output of the audio, the most frequent problem is an inadequate power supply. The current draw of the receiver is 440 mA, but the TDA2002 can draw instantaneous power peaks of almost one amp during voice and CW peaks.
The audio will have a hum in the output if a wall-wart (plug-in wall transformer/rectifier) is used, even if it is rated for 1 amp. There is not enough filtering and most are not regulated. Some may work, just be aware that they can cause hum in the audio.
The TDA2002 is rated at 8 watts output. Use a 4" to 12" speaker rated at 8 watts or more.
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