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Re: LM386 CONNECTION

 

Hi Curt,

Thanks for the revert.
I have tried to set the BFO to the best signal on 20m? but even then it is distorted.

There is also a 2Khan- ve shift.

I read on the forum a out a separate audio amp improving the audio quality. Hence thought about tinkering.

Some of the fellow hams in Mumbai which is my QTH also told me that the calibration also needs to be redone.

Am trying to locate a frequency counter to perform the 10mhz calibration my self.

Regard?

Rajesh
VU3RHU




On Wed, 1 Jul 2020, 07:41 Curt via , <wb8yyy=[email protected]> wrote:
Rajesh

Do listen with headphones to see if audio is still very distorted.

These boards usually arrive with the BFO not properly adjusted. If the signal is coming too close or beyond the edge of the crystal filter passband this can cause significant distortion. Its the setting of the BFO that determines where the audio signal sits when it passes through the xtal filter.

A smaller thing, some of us modify the lm386 circuit for a better sound. This info is on the web. See la3za website,? but this is a minor aspect.

Check simple things before presuming its a circuit issue, it may not be.

Curt wb8yyy
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