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QCX-SSB: SSB with your QCX transceiver schematic


wb2cba@...
 

Hi all,

first post here. Actually this is a question for Guido. 

I will try to build this mod on perfboard and eventually a dedicated pcb. Can I use this schematic ucx.png? It is slightly different from the main Mod  schematic so I wasn’t so sure which one to use. Thank you.

73’s 

Barb, WB2CBA


Dean Smith
 

Hi Barb,.
There's quite a bit missing from this layout apart from power connections. I have placed components on pcb sprint here. Just got to wire it  all when time allows. It should make for a much smaller footprint. Kicad would be the answer but learning curve here, used to pcb sprint 6 for my sins :).  Anyhow good luck with it.
Dean


LY5NF
 

I wanted to transfer this schematic over to a PCB too. I am very interested in this project, as this seems like the cheapest way to get into HF SSB. I haven't touched HF ham in over five years, because I had to sell my Yaesu rig. I don't have enough time to be able to justify buying an expensive transceiver these days, so this simple little project would be good enough and a fun way to spend my limited free time building it.

I ordered some parts from Aliexpress (mainly the ICs), and in the meantime until they arrive, I thought I would design a PCB. However, I'm not an RF engineer, and I don't really have experience designing and laying out PCBs. Currently, I have transferred this exact ucx.png schematic over to KiCad, and I feel like I simplified it a bit. I separated some of the parts in to blocks so it's easier to follow, and I added header pins instead of a discrete LPF, so you could use Hans' excellent LPF modules.

At this moment I don't have enough free time to work on a PCB layout, so if anyone is interested, I can share the KiCad project file (for now I added a .png, but beware, there could be errors, mistakes and just dumb layouts, again, I just wanted to play around with KiCad) and if there is someone who is willing, they could design a PCB and share the complete KiCad project here. Again, I don't expect my schematic layout to be great, but it could be a head start for anyone who would like to design a PCB.

And these days, getting two layer PCBs is cheap as beans, thanks to such services as JLCPCB (10x10cm, 5 PCBs, any color - less than 2 EUR + shipping). So this definitely could be the cheapest HF SSB TRX to date. I'm still waiting for the QSX, but I really want to have a TRX to play around with this summer.

73 de LY5NF


Glenn S
 

Hi,

I am loading the schematic into KiCAD, its' the first time I have used it, and pretty intuitive so far.  I noticed that pin 14 on the Si5351a should be pin 4.

Cheers,
Glenn VK3YY


Manuel; DL2MAN
 

Hi there,

Actually Guido and me were discussing the exact same thing, and I started to put everything together in KiCad.... So I´m (we´re) at the exact same level as LY5NF at this moment.
Right now we had some minor design drawbacks, while testing stuff, but that sohuld not be relevant when it comes to PCB Layout. More an issue of component dimensioning.

I do mechanical CAD-Design for a living, but I have absolutely no Experience in PCB Design and Layout.

So maybe we have some other OM´s, that feel more confident about what they are doing and want to contribute to this project ?

Any help welcome.....

73 Manuel; DL2MAN


Glenn S
 

Hi LY5NF,

I missed your post earlier, your schematic layout is very neat! Looks like a few of us are all doing the same thing.  My interest is a compact form factor and lightweight transceiver for SOTA operation.

Cheers,
Glenn VK3YY.


wb2cba@...
 



 Thanks all for your replies and glad to see that I wasn’t the only one interested in dedicated pcb for this great mod.

I am planning to use Kicad too. I also want to use multiple lpf’s selectable with relays to cover multiband operation on pcb. Same aim here, a compact sota ssb transceiver.

My only problem now is to refine a schematic that works. If Guido can throw some guidance on this that will be great.

73’s

Barb


wb2cba@...
 

The other idea that came to my mind is that if Arduino nano modules can be used in this mod if the firmware xtal freq can be lowered to work with 16 mhz in the firmware. This will allow easy programming over usb and usb connection for CAT control in the future?  I contacted Guido by mail for this idea. Haven’t heard back yet. 


73’s

Barb


LY5NF
 

Yes, an Arduino Nano would be a good solution. it uses the same ATMega328p chip, it has all the pins brought out to pin headers. As for it's frequency, the Nano doesn't use a crystal, instead the frequency is set by it's internal PLL. So if Guido's firmware couldn't run on 16MHz, we could just edit the boards.txt file in the Arduino IDE to force the Nano to run at 20MHz.

See here for details: https://forum.arduino.cc/index.php?topic=624037.0

I'm all up for switching to a Nano. They are just as cheap, you don't need an external programmer, and a CAT interface could be integrated via USB. Of course, we could also think about other MCUs that are Arduino IDE compatible, like ESP8266 or ESP32 that even add Wifi and Bluetooth support, much faster speeds, cheap prices and other goodies (it's got some DSP stuff too), but for now I'd say lets not branch out too much and stick with ATMega328p.

73 de LY5NF


wb2cba@...
 

One more thing that came to my mind is to switch the SI5351 xtal to 25 mhz in the firmware and use those cheap SI5351 modules in the pcb design. It is not easy to smd solder SI5351 on pcb.Those SI5351 modules will make it easy for everyone to solder. Just a thought :)

73’s 

Barb , WB2CBA


peatmoss - ki6ssi
 

Hi Jokubas,

Can you share your KiCad file? I was thinking the same thing, mostly a smd board but I have little experience in the layout.

Thanks!
Pete


LY5NF
 

Hi ki6ssi,

I have attached the zip to my KiCad project. It's got the schematic on there (should be rechecked and probably cleaned up, I have no experience and I didn't follow many schematic layout rules) and the PCB footprints are done as well, but these can be changed to your liking.

I hope others will contribute to the PCB layout design.

73 de LY5NF


John VA7JBE
 

Hi folks,

I have also built up my own pcb in kicad and it’s pretty much ready to get fabricated. I decided to design mine with a focus on portability for SOTA. I also added extra low pass filters for multi band operation and a simple broadcast HPF on the receiver input. The display is a OLED and the uC was switched to the TQFP version of the atmega328, otherwise everything is the same as the schematic from Guido. This was my first full transceiver build in kicad and I’m really excited to see how it turns out!

Cheers,
John VA7JBE 


John VA7JBE
 

This is what the board preview looks like, the PCB size will be 100x82mm (or roughly the same size as the original QCX).  You can see that a lot of space is taken up by the LPF bank, you could probably fit the core circuitry on a 50x50mm hoard.


Manuel; DL2MAN
 

Hey John, 

Great Job ! Looks pretty interesting ! Seems like you know what you´re doing !
I´m exited to hear, if it works.
Is it 2 Layers or more ? Looks like Multi Layer....

73 Manuel; DL2MAN


John VA7JBE
 

Thanks Manuel,

This is a 2-layer board, there are a handful of components on the other side.  Most 4 layer boards experience a significant price jump if you go large than 50x50mm.  I'm definitely not a professional but I've been lucky enough to spend some time with people who do this for a living and I try to apply proper design rules when I can remember them ;) 

Cheers,
John VA7JBE


Simon G0FCU
 

Heads up to anyone whose email client downloaded the message that Gmail tells me contains a virus. Be careful out there!

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Date: Tue, 19 May 2020, 16:52
Subject: Re: [QRPLabs] QCX-SSB: SSB with your QCX transceiver schematic
To: Simon Kennedy


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peatmoss - ki6ssi
 

Nice Board John!

Any chance you can share your work or order me a board :) I'll pay of course.

Thanks
Pete


Ryan Flowers
 

Why make a PCB? I think the fun of it is that it's a hack! If it gets its own PCB, then it's not a hack, it's a new product. And if you're going to go to the trouble of doing a new PCB, you may as well use a better processor than the 328p. And down the rabbit hole you go...
--
Ryan Flowers - W7RLF
MiscDotGeek - QRP and More


Jim Koehler
 

Hi Guys,
I've already done a layout and had some boards made.  The board is just slightly larger than the LCD and uses SMD parts throughout.  The FST3253 is no longer available from a distrbutor (I've seen some on eBay) as SOIC-16 but is available as TSSOP-16 which is a finer pin spacing.
I'm waiting for some parts but I have built up a chassis and assembled the basic unit but not yet wired the controls. 
Jim, VE5FP