This guy has some good info on adding a DDSVFO to a radio. He has some great explanations of how it works and what to do. He offers the Arduino program on his website for free download too.
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Arduino DDS VFO Home Brew
- Thread starter Shadetree Mechanic
- Start date
Thanks for posting that!
Grabbed his VFO sketches from his site. Don't think I would do the channel selection as a case statement. The end result is the same, though. Get the user to the channel they want with the minimum amount of fuss on their part.
I might have to steal his EEPROM code for saving data across power offs. Having the radio come up on a different channel than it was when you powered off can get kind of annoying.
Grabbed his VFO sketches from his site. Don't think I would do the channel selection as a case statement. The end result is the same, though. Get the user to the channel they want with the minimum amount of fuss on their part.
I might have to steal his EEPROM code for saving data across power offs. Having the radio come up on a different channel than it was when you powered off can get kind of annoying.
I have been following your work in the thread you made:
https://www.worldwidedx.com/threads/sbe-sidebander-vi-pll-problem.267060/
That is a neat project and the radio is certainly worthy of such an undertaking. I just don't know that much about these micro controllers, but I get the jist of the code. It reminds me of the Basic programming I did with my Commodore 64 back in the day when I was a kid.
I would really like to find a good way to replace the oscillators in the drifty old Galaxy radios that I have. Something more simplistic than a VFO. Something that retains the factory channel selection and appearance. I am not completely sure how this all works, and maybe its easier than I think. Is there an easy way to do this? These new Anytone radios have my Galaxies sitting on the sidelines.
I only started the project because that radio was completely dead and the part that failed is pretty much unobtainium. So basically I'm playing out my desperation move in a public forum. Probably not all that bright a thing to do but it does give you guys something point at and laugh about.
I didn't jump in knowing all that much about how to program for the Si5351 module. OK, I had no clue how to do it until I stole a bit of code from the guy that posted this video:
My understanding about the older Galaxy radios is that they drift due to crystals reacting to temperature changes. Never owned one, I just know the rep. So the first things you'd need to figure out are:
How many frequencies do I need to generate at any one time?
Do they change with the various modes (AM, SSB, FM), ie, offsets? I they do, how do I replicate that?
If I'm replacing a crystal, does the clarifier pull that crystal at all? If it does, how am I going to replicate that?
And that's just for the crystals. If you want to replace the PLL and VCO as well then it gets even more fun.
Not saying it's not doable. It's totally something you can do. Just that it may not necessarily be "easy." You would need to gather info and make design decisions for your project based on that, and that's going to determine how hard or easy it will be.
Oh, and doing lots and lots of google (or whatever search engine) searches for code examples. (Quick tip, only steal the good stuff.)
But if you pull it off then you'll have some rock solid radios, and other owners of those models will be asking how you did it. Even after you make your schematics and code publicly available. People are weird like that.
