Alex, I now understand that you had used co-ax cables to connect the clocks to main board.
?if the raduno is farhans original, why not try direct connection once with no cables.
Secondly, I suppose (again I suppose) Farhan himself is using such Nanos only. Nothing vwery special.
Hence can you please to clatrify whether these clicks could also be due to CH340 USB chip in case you use computer related FT-8 etc?
?If so original nano has to be? checkd for whether original NANO used CH340 or FT232RL or any other chip.
Finally try to use a 1mH choke on the 12V dc line with proper filter. Also can you place 10nF? smd caps on the rotary encoder pins to ground. I suppose those clicks are due to encoder rotation.
?With these changes, perhaps the clicks can be minimized. Please don't feel that I am re-inventing the wheel, LoL
On Thu, Feb 22, 2018 at 7:01 PM, Alex Buurlage <pa1fox@...> wrote:
Hi all,
I have replaced the Nano in my homebrew rig as one of the IO ports was dead. Now, with the new Nano, same firmware, same rig, I have a lot of tuning clicks.? When I disconnect the SI5351 the clicks are gone. When I disconnect the coax cables from the mainboard carrying the oscillator signals, clicks are nearly gone.
When I put back in the original Nano, clicks are hardly audible as it used to be until now.?
Has anyone found such differences in behaviour between cheap Nano boards from Ebay? Reviewing the method I2C works, I can't really imagine the big difference in behaviour as the output ports of the Nano seems to be open drain mosfets and the pull-up resistors at the SI5351 are the same.
Even with the volume pot completely down the clicks are very loud with the new Nano. One should think it is ground looping somewhere differently with this new Nano.
