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high frequency noise from speaker

 

Though it took a little longer time, finally my uBitX seems to be working very well now, for which thank you for advices here so far.

Then, another question to ask you who experienced the same issue.

I hear high frequency noise behind the band noise that my iPhone freq meter says it’s about 2,700Hz. (I’m not sure if this app is reliable or not)

My uBitX is not in a metal case, yet. And I use a small powered speaker.

Maybe it comes from Raduino or main board of uBitX, or possibly the 12v power supply.

Since I’m planning to bring my uBitX to a local lab in order to measure its spurious emission this coming Wed, I’d like not to mod much things on hardware coz it may possibly bring another trouble to me.

I just hope that some capacitor in the line of speaker or some small mod can solve this issue at this moment.

Looking forward to your advice.

Thanks!

// hiro, JJ1FXF
 

Here's an old thread about audio tones in the receiver,
possibly due to beat notes between harmonics of the 12mhz bfo and the 16mhz Nano processor clock.
? ? /g/BITX20/message/54576
Easiest solution if you have a v4 uBitx with the socketed Nano:? replace the Nano

Jerry


On Sun, Aug 12, 2018 at 07:58 PM, JJ1FXF wrote:
Though it took a little longer time, finally my uBitX seems to be working very well now, for which thank you for advices here so far.

Then, another question to ask you who experienced the same issue.

I hear high frequency noise behind the band noise that my iPhone freq meter says it’s about 2,700Hz. (I’m not sure if this app is reliable or not)

My uBitX is not in a metal case, yet. And I use a small powered speaker.

Maybe it comes from Raduino or main board of uBitX, or possibly the 12v power supply.

Since I’m planning to bring my uBitX to a local lab in order to measure its spurious emission this coming Wed, I’d like not to mod much things on hardware coz it may possibly bring another trouble to me.

I just hope that some capacitor in the line of speaker or some small mod can solve this issue at this moment.

Looking forward to your advice.

Thanks!
 

Many thanks, Jerry.

It seems that my issues is the same one discussed at the thread you pointed out.

I happeningly ordered some extra Arduino Nano for my another projects, so let me try to switch Nano at first.

What do you think How many of Nano I can buy to get the right one?

I’m just asking you the possibility. No commitment, of course.

// hiro, JJ1FXF



2018年8月13日(月) 12:39 Jerry Gaffke via Groups.Io <jgaffke=[email protected]>:

Here's an old thread about audio tones in the receiver,
possibly due to beat notes between harmonics of the 12mhz bfo and the 16mhz Nano processor clock.
? ? /g/BITX20/message/54576
Easiest solution if you have a v4 uBitx with the socketed Nano:? replace the Nano

Jerry


On Sun, Aug 12, 2018 at 07:58 PM, JJ1FXF wrote:
Though it took a little longer time, finally my uBitX seems to be working very well now, for which thank you for advices here so far.

Then, another question to ask you who experienced the same issue.

I hear high frequency noise behind the band noise that my iPhone freq meter says it’s about 2,700Hz. (I’m not sure if this app is reliable or not)

My uBitX is not in a metal case, yet. And I use a small powered speaker.

Maybe it comes from Raduino or main board of uBitX, or possibly the 12v power supply.

Since I’m planning to bring my uBitX to a local lab in order to measure its spurious emission this coming Wed, I’d like not to mod much things on hardware coz it may possibly bring another trouble to me.

I just hope that some capacitor in the line of speaker or some small mod can solve this issue at this moment.

Looking forward to your advice.

Thanks!
 

Hiro,

I would think with 3 or 4 Nano's you would have one without the objectionable tone.
The processor clock frequency is determined by a 16mhz ceramic resonator
which can be off by perhaps plus or minus 100khz.
Since it is probably the 3'rd harmonic of the 16mhz resonator creating the tone,
if it is off by 10khz, then the tone would be 3*10khz = 30khz.

Buy Nano's that do not have the pins soldered in such as this:
? ??
To plug the Nano into the Raduino's socket on the v4 uBitx, the pins must be soldered?
into the top side of the Nano, not the bottom side where the pins usually are.

Jerry


On Sun, Aug 12, 2018 at 10:24 PM, JJ1FXF wrote:
Many thanks, Jerry.
?
It seems that my issues is the same one discussed at the thread you pointed out.
?
I happeningly ordered some extra Arduino Nano for my another projects, so let me try to switch Nano at first.
?
What do you think How many of Nano I can buy to get the right one?
?
I’m just asking you the possibility. No commitment, of course.
?
// hiro, JJ1FXF
?
?
 

Jerry,

Thanks again for ur reply.

OK, 3 Nanos are on the way now and I will order another 3 Nanos so I can try 6 of them this time.

Yes, I know that I need Nanos without pins soldered.

Maybe I’ll solder “both sides long pins” then I can use in anyway later.

So far, my uBitX is working good, I could listen some HAMs on 7MHz and could transmit 5W on CW and 10W PEP on SSB if I shout to the mic.

Next to do is to build a transmittable antenna.

Again, thank you so much. I’m enjoying my uBitX now.

BR,

// hiro, JJ1FXF



2018年8月13日(月) 14:46 Jerry Gaffke via Groups.Io <jgaffke=[email protected]>:

Hiro,

I would think with 3 or 4 Nano's you would have one without the objectionable tone.
The processor clock frequency is determined by a 16mhz ceramic resonator
which can be off by perhaps plus or minus 100khz.
Since it is probably the 3'rd harmonic of the 16mhz resonator creating the tone,
if it is off by 10khz, then the tone would be 3*10khz = 30khz.

Buy Nano's that do not have the pins soldered in such as this:
? ??
To plug the Nano into the Raduino's socket on the v4 uBitx, the pins must be soldered?
into the top side of the Nano, not the bottom side where the pins usually are.

Jerry


On Sun, Aug 12, 2018 at 10:24 PM, JJ1FXF wrote:
Many thanks, Jerry.
?
It seems that my issues is the same one discussed at the thread you pointed out.
?
I happeningly ordered some extra Arduino Nano for my another projects, so let me try to switch Nano at first.
?
What do you think How many of Nano I can buy to get the right one?
?
I’m just asking you the possibility. No commitment, of course.
?
// hiro, JJ1FXF
?
?

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