MTR Update – Increase audio

 G3CWI pointed out that that can solder a 10uF capacitor between pins 1 and 8 of the LM386 to increase the audio gain by 200%

Lm386 gain

The complete data sheet is here – http://www.ti.com/lit/ds/symlink/lm386.pdf Page 6 shows that adding the 10uF cap increases the gain from 20 to 200.

The sidetone gets added later in the audio chain, so this mod will not affect sidetone level.

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One response to “MTR Update – Increase audio”

  1. vk3yy says :

    Hi Allen, I found that the mod increased the level too much on 40m and the limiter is hard limiting on most signals, its also a bit loud in the earphones. Levels are fine on 30m and 20m where there seems to be less gain in the receiver. I plan to reduce the gain a bit with a resistor in series with the capacitor.

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