I would like to build a minimalistic
AF chain for small HF receivers,
that would limit the audio passband
to either 300-2800 Hz or 700-900 Hz.
The LM386 audio amplifier has a tempting inverting input.
Did anyone try to design it into a 1-device
audio filter + power amplifier?
I looked around, pored over the applications sheet,
but found no examples.
I did this playing with TAA611's many years ago. Then I did find
rather clear indications on how to lower the high frequency cutoff -
but nothing similar with the LM386.
Any hints?
Or,
why isn't this done
as a matter of course,
as I
perhaps mistakenly
think it should?
73 de n1jpr/i2
http://filippo.ru.ru
http://webfools.net/filippo/desert-ratt.html