Re: Latest Build, Mods and results.

Jerry Gaffke

That should work fine.

Take the filtered sidetone from the junction of R252, R253,  add a 10k pot from there to ground to attenuate that audio signal,
the attenuated signal goes through a switch and a series 1uF cap to the base of Q6.  Flip the switch on to enable this feature.
Only software change needed is to turn the sidetone on when tuning.  Adjust the pot for the desired power level during tune.
No additional Nano pins required.

Could do away with the pot, use two fixed resistors there to set maximum tuning power, and adjust the duty cycle
of the sidetone to reduce power under program control as you suggest.   The simple tone() function call currently used
is fixed at 50%, need to find some other way to create that tone.  Harmonic content of the tone would predominate
as duty cycle is reduced, but the RC filter at R250,251,252 should mostly take care of that.

Alternately, could use a spare Nano pin to drive a second RC filter that only injects its tone into Q6,
leaving the current sidetone  generator alone.  Then you can do without the extra switch.

Or create a tone using a smartphone app.
Or whistle softly into the mike.  

Lots of ways!


On Wed, Jun 13, 2018 at 08:46 am, brad martin wrote:
Just an idea, Ignore CW tone all together and focus of SSB.  Now if I understand right SSB output power is based on the audio in volume.  You yell into the mic you put out more power, you whisper you get less.  At least thats how its showing on my SWR meter and my power supply amp meter.  The CEC firmware can already do WSPR on its own with a push of the PTT button.  What if we implemented a tune feature that just produced a 700khz tone on SSB and you can vary the output power by simply (I assume) changing the output voltage/duty cycle of the tone.  Thinking it would go something like this, Change mode to tune, Push PTT to send a tone,  In the software it will change the duty cycle to generate 1W out on the band you are on.  On 40m that may be a 10% duty cycle where on 20m it may be 60%.
For me I am OK at best with hardware mods and a better coder.  Now off to clone CEC firmware repo to see if it can be done.

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