New Si5351 Breakout Board with FM and TXCO Part 1

In this video I take a look at a new Si5351 breakout board that I have been developing. The unit incorporates a facility to modulate FM with a 2ppm TXCO for extra frequency stability. This video covers the basic operation of the device. Please feel free to leave comments.

[@user-se5jc3gw1y]

Great Job John .... I'd be interested in a couple of these boards when the hardware and software become stable .... 73 .... Dean KL7MA

[@gabrielmanole7101]

Meeee tooo amazing John!!!! Great job!!!

[@VK3TWO]

Excellent work. Look forward to seeing more!

[@gmarf1]

Interesting work I was thinking of modifying my old 2m rig using the Si5351B as the FM generator, and I liked the display and controller. When you get some more boards (the board shown is this video) I would like one thanks. Paul, G6SAA

[@M0XFXUK]

Hi Paul, thank you for your comment. The si5351B breakout board with FM modulation capabilities is now fully designed, tested, and ready for manufacture. However, if I'm honest, I'm not in a position to distribute these boards at this time. The board shown in the video is a prototype, and I have since refined the design. As a radio electronics hobbyist and enthusiast, I have designed the board as an open-source project. Given the interest in this board, I believe it would be a great seller. With that in mind, I have reached out to several manufacturers, including Adafruit, to explore manufacturing and distribution options so people can get hold of them for their projects. Regarding the controller board (Band Surfer MK2), I have been developing it for quite some time and am nearly ready to move on to the next step of getting it into the public domain. Again, I am exploring manufacturing avenues. Thank you again for your comment, and suggestions are always welcome. I am in the middle of making more videos about these projects, which will be available very soon. regards John M0XFX

[@paulsradiohacks]

So going to use this on my homebrew radio.

[@M0XFXUK]

Keep an eye on the channel as I will make a video when I get them manufactured.

[@multilecful]

Great work my friend

[@SimjetAU]

Great video John..looking forward to the next one.

[@M0XFXUK]

Hi Mark, hope you are well mate. I have finally found some time to do stuff again. Great to hear you liked the video

[@RazorRadios]

Nice work John! Fantastic solution for FM.

[@M0XFXUK]

Yes and I think it's a really useful feature. thanks for the comment.

[@Ghost_Swe]

Awesome job!!!!!

[@M0XFXUK]

Thanks!!

[@CBRadioWayBack10-4]

nice President Grant :)

[@AmauryJacquot]

fantastic job ! hi, would this chip be able to modulate on 6Mhz with 70kHz deviation ?

[@M0XFXUK]

That's an interesting question. To be honest, I have only tried narrow FM from 10 MHz to 200 MHz with a maximum deviation of around 10 kHz. Theoretically, I would say it's possible, but I am unsure how the PLLs and multi-synths would react. I'm making a video carrying out some performance testing and will take a closer look at this. Thank you for your comment!

[@paultomlinson528]

Can this be used for a homebrew hf set ? Or is it biased towards cb radio mods

[@M0XFXUK]

Hi Paul, thank you for the comment. The new breakout board can be used for any purpose as long as it's within the frequency range of the clock generator 8KHz to 200MHz. So HF and VHF would be fine. I just used an 11 meter radio as it was easy to demonstrate it working. I am in discussions with Adafruit with a view to them producing the unit so it will be available for people to buy. Watch this space.

[@LeonardDiSanza]

Thanks, so any chance you might be selling these boards in the future?

[@M0XFXUK]

Hi Leonard and thank you for your comment. Yes we are planning to make them available, we are trying to get them manufactured in China. We can supply one off boards that we assemble however; they are quite expensive.

[@LeonardDiSanza]

@@M0XFXUK Well I'm getting too old (dexterity and vision) to do much surface mount stuff anymore so assembled would be the only way for me to go. I'll bet however there will also be many others that will be interested in assembled units for the increased stability of the TXCO. Please keep us informed through your future videos.

[@robertdec3713]

Very intresting, but... how it's realized FM modulation? Via I2C or via cap diode on 25MHz osc? some schematic?

[@M0XFXUK]

Hi Robert, I like the way you are thinking however; the I am using a type B si5351 with a built in VCO to modulate the FM. The the deviation level is set via the I2C. I am currently make part 2 which going through how it works in more detail including schematics and code.

[@robertdec3713]

@@M0XFXUK Ah, ok. Thanks for answer. I'm thinking about using a varicap diode to modulate reference oscillator (with A version), but it will probably be difficult to control the deviation when the carrier frequency changes... And i dont know if PLL is fast enough for 3kHz Fmod.

[@M0XFXUK]

@@robertdec3713 If I am honest, I think it would be a bad idea to mess with the reference oscillator frequency as the frequency stability would be all over the place. Using the type B IC I can modulate up to 10KHz deviation without any issues. I am making part 2 which should be out tomorrow.

[@ScottGladstone]

Great. I've been looking at tacking on a TCXO to the original but it's a pain. The FM is a bonus, I'm guessing you're using the next version up with the analogue pin. I didn't know a TXCO was available in such a tiny package.