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Re: audio dropping out


 

I don't think anybody feels insulted here just yet.
Just a bit of confusion.

You have a very weird problem though:

> I get audio spontaneously dropping out. If I just touch these wires it comes back.
> It's like a capacitance issue. Just lightly touching the yellow or orange or both wires brings the audio back


and later:

> the audio always dropped out when there where a lot of strong stations on or nearby in freq.
> I think this is a case of of the processor getting swamped due to lack of AGC.
> The audio always comes back after a bit, even if I just leave it alone! Thoughts?

I don't think we have seen a problem quite like that before in the forum.

Your first post makes it look like a bad cable.? Sometimes the wire is? not attached?
to the cable connector correctly, a bad crimp job.? You could diagnose this by
using an ohmmeter between the bottom of the uBitx board where the connector pin
is soldered in place and the far end of the cable, then use your third hand to jiggle the cable

But your second post sounds more like? a circuit problem.?

The fact that the problem occurs either when there is a loud radio station but is affected when you?
touch the wires suggests it is somewhere between the volume pot and the speaker.

Does the problem also occur when you have the volume set so low that you can barely hear it?
?
If you have some other
audio amplifier such as a project with an LM386 in it or perhaps some old computer?
speakers or hi-fi audio amp, you might try running audio from the middle pin (wiper) of the volume pot
over to this other amp, also a ground wire.? Put volume pot at minimum, power up, then
slowly turn up the volume a bit till you can hear the radio.? If the problem does not come through,
then it is probably something wrong with the TDA2822.

The Nano processor on the Raduino never sees the audio, so it will doesn't get overloaded.
But the TDA2822 might be doing something funny when it sees loud signals.




On Mon, May 28, 2018 at 12:15 pm, Dave de WS1ETI wrote:
I meant no insult. I was confused. I see it turns out I was not being clear. I apologize.?Can we please start over?

What was your idea, on the uBITX audio problem I described?

Thanks,
Dave

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