Curt,
Can you not simply connect the RIT line to one of the Arduino analogue
inputs and use that to generate a proportional frequency offset? That's
what I did in my PIC controller.
Steve G3TXQ
On 26/10/2017 01:47, Curt Benjamin via TenTec wrote:
Guys, since the N4YG DDS is no longer available and too expensive anyway, I
have been exploring the idea of making my own. So far, I've taken the Arduino
code to control one of those $8 AD9850 DDS modules from China to tune from 5 to
5.5MHz but I haven't found a way to add an RIT line to it.
What I'm thinking might work is making something like a 2MHz xtal oscillator
with a voltage-controlled shift line using a varactor and mixing that with the
Arduino/AD9850 DDS that tunes from 3 to 3.5 MHz instead.
I don't think any of these frequencies would pose any problems in either the DC
receiver in the C21/22 or in any of the superhets of the other various models
but I'm not sure. What do you folks think? Is that a good scheme or should I
change the frequencies. I picked 2MHz because it's available in a off-the-shelf
crystal. Thanks.
Curt, K8AI
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