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etherkit / Si5351Arduino

Library for the Si5351 clock generator IC in the Arduino environment
GNU General Public License v3.0
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Erratic frequency Si5351A Arduino Uno #73

Closed realbird616 closed 4 years ago

realbird616 commented 4 years ago

Hi, Just run the Example sketch and the results is 42.XXXMhz. not the expected 14.XX Mhz Changing the CLK0 output to 10 MHz with " si5351.set_freq(1000000000ULL, SI5351_CLK0);" and I will get 10.Mhz.!! The same with an input of 12 will give 12Mhz. Between 13 and 29 will give irrelevant values. Restarting at 30 is then OK ?? I have clean re-install libraries and even try from another computer, same results. If I use the Adafruit sketch I can get all frequencies normally from A or B on that board.

NT7S commented 4 years ago

Are you using some kind of breakout board or is this a custom circuit?

realbird616 commented 4 years ago

Hi, No breakout board. Si5351 connected directly to Arduino. I think it work only once displaying 14MHz ?

On Dec 20, 2019, at 4:42 PM, Jason Milldrum notifications@github.com<mailto:notifications@github.com> wrote:

Are you using some kind of breakout board or is this a custom circuit?

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kf4mot commented 4 years ago

Are you sure you're not just seeing the 3rd. harmonic? The output of these things are loaded with them.

realbird616 commented 4 years ago

I can’t say, I dont have a spectrum analyzer but it looks as a multiple of the requested 14 Mhz. With the Adafruit sketch no problem getting 14 Mhz on my HP freq.counter.

On Dec 20, 2019, at 4:52 PM, kf4mot notifications@github.com<mailto:notifications@github.com> wrote:

Are you sure you're not just seeing the 3rd. harmonic?

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kf4mot commented 4 years ago

Do you have a hf receiver you can try to listen in on? I don't think I'd trust a counter to show the fundamental of a square wave. If you can add a lpf in line with the counter that may help. That doesn't explain it working with the Adafruit code, but that could just be a coincidence with your test setup.

realbird616 commented 4 years ago

You are absolutely right. I was relying blindly on this HP5316A. With a 2pf it’s now showing the fundamental at 14.Mhz. I should have tried my 30 years old Fluke that was right on with no filtering. Tks again

On Dec 20, 2019, at 7:02 PM, kf4mot notifications@github.com<mailto:notifications@github.com> wrote:

Do you have a hf receiver you can try to listen in on? I don't think I'd trust a counter to show the fundamental of a square wave. If you can add lpf put in line with the counter that may help. That doesn't explain it working with the Adafruit code, but that could just be a coincidence with your test setup.

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