Another solution would be to separate the Si5351 from the raduino. Put it on its own board that plugs into the uB. Pins 10-16 pass thru to another connector. Another connector connects the I2C to the raduino. Then you can put the UNO part of the raduino (or use something else entirely) wherever you want where the Xtal won't be an issue. That also gives more options for boxes and mounting.
I have it partially finished in KiCAD but other things have gotten in the way so it's on hold. I tried to get Mike Hagen to do it but he didn't seem interested.
Vince.
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On 04/09/2018 09:46 PM, Jerry Gaffke via Groups.Io wrote:
What we need is a scratch built Raduino board that takes an ATMega328P chip,
an si5351, regulators for 5.0 and 3.3 volts, and has a carefully
chosen frequency
on the oscillator for the processor. Or at least a randomly chosen
frequency.
No USB interface, just some pins to hook an FTDI USB-UART cable (or
similar) up to the host.
Another possibility is to hang a cap across that 16mhz resonator by the
ATMega328P on your stock Nano
to bring the frequency down, hopefully by a few tens of khz.
But the resonator is ridiculously small, I can't really recommend that
hack to thousands of ubitx owners
with nothing but blunt instruments for soldering with.
Also, the Nano has that USB interface with a 12mhz resonator, could also
be wreaking havoc with our 12mhz BFO.
Unfortunately that's on the backside of the Nano, no chance of putting a
cap across that 12mhz resonator
unless you first clip the Nano free from your Raduino.
Once the Raduino is certified free of 12 and 16mhz, we can go back to
Farhan's original plan of moving the BFO
above or below the 12mhz crystal passband to select LSB/USB. And CLK1
can remain stuck at 45+12mhz,
which should avoid some some of the extra birdies we get when it's at
45-12mhz for LSB.
Jerry, KE7ER
On Mon, Apr 9, 2018 at 03:46 pm, John wrote:
Hello Jason,
On mine, I noticed that the tone frequency would change the most
when I adjusted the BFO frequency.
If you re-calibrate the BFO to a slightly different frequency, does
you tone move as well?
A more complete test would be to try Ian Lee's software version 1.61
and use the IF Shift function to see if that moves your tone.
If it does, you could try to shift the IF so that the lower
frequencies are emphasised and continue in the same direction until
you have reversed the sideband. If in that position, after swapping
the sideband in the menu you can receive signal properly without an
audible tone, then we can look at swapping them in software.
If this does not work, you could try to move the first IF instead.
You could load the test version I uploaded in the files section in
the "Software based IF attenuation" folder and through the menu
change the first IF and see if your tone moves in frequency.
Then we can it from there.
Good luck. This issue drove me nuts...lol.
73, John (VK2ETA)
--
Michigan VHF Corp.
