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Variable frequency oscillator design for HF

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Radiotech:
I have only used crystal oscillators for my builds, but crystals can be hard to find that match the frequency you want to transmitt on. Is there any good and simple VFO altnernatives for HF using a colpitts oscillator for example?

I am looking for something like the lower example in this image, from the ARRL handbook. Is this something i should go for, or is there better and prooven designs?

Stretchyman:
The AD9833 is $2 on a PCB wi a CLK from CH. Sure it needs SW to drive it but I can send you that for whatever frequency you want. You'll need to use an attiny45 and a transistor or 2 to amplify the signal but then you can have any frequency you want (1-10MHz) with Xtal stability.

It's an option for you.


Str.

Teotwaki:
The AD9833 is one easy way to break free from fixed crystals. I have one on the bench and use an Arduino "Nano" board to control it. There's lots of software already available. It's easier to use the square wave output and filter it as the board's  sine wave out is fairly poor quality.

If you want something you can just use without software and a microcontroller there are modules with everything on the board to allow it to act as a VFO. Depends on your skills and budget as well as what you define as simple

Radiotech:
Looks interesting, i will think about it!

I tested a few crystals i got on line, but they didnt work. Some of them(the one on the right) worked very well, but the one on the left didnt work at all, both the same frequency though. Is there any difference between them that is important(besides the size)?

Teotwaki:
I don't know how you are testing them but crystals can be designed to operate properly in either a series or parallel resonance mode

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