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Jonathan,

Be aware it might not be as trivial as it looks.

The transformers are described here:
? ??
Search for "Coil Details".

The KiCad files are not available, that was some sort of requirement
when they set up HFSignals to build this stuff.
Perhaps to get a business loan they had to keep some part of the design private.
The remainder of the design is open source, and building from scratch is encouraged.
The uBitx is a two layer board, the bottom side is mostly ground plane.
Perhaps just build "ugly style" or "Manhatten style" on copper clad circuit board,
that way you have a solid ground plane under the entire design, which is highly recommended.

All quartz crystals in that IF filter should be matched by hand to within 100hz or so,
that means building a crystal oscillator and having some way to accurately measure frequency..
If your quartz crystals have different characteristics than what hfsignals uses,
you will need some way to determine the passband of the IF filter and adjust the filter shape
as described in Experimental Methods in RF Design (and/or search for Dishal on the web).

You will need some way to sniff and measure RF, an Antuino would be ideal,
though you might get by with a diode RF probe and a Harbor Freight DVM.
A good scope would be nice, perhaps 50mhz or more of bandwidth.
The nanoVNA would be worth looking into, shows complex of 1 and 2 port networks,
and thus is an education in itself.

If you are serious about studying "RF and Microwave", all of the above is worth the investment.

And lastly, maybe get a working uBitx from hfsignals, so you can
know for sure what the signals levels really should be when yours does not work.

Many have built radios like the uBitx from scratch.
But few find it easy.

Jerry, KE7ER

I have a v5 ?BITX that I've been fiddling around with for a while, and it looks like just about all the stuff I'm interested in being able to do with it will be better-enabled with the CEC firmware.? So, I got v1.200 and built it (I still have the stock parallel display) because I could not for the life of me make any of the hex loaders work - but was able to build and load it using the Arduino IDE.

So far, so good.? There are a number of issues with it that I expect will all get worked out eventually (for example, the CW filters make a CW signal barely audible - I've seen allusions to that issue on this board, and to there being settings which help, but I have been unable to find those settings.

I also just grabbed the uBITX manager software, v1.110 - I was disappointed to find out it was a Windows program, but managed to dig up an old laptop.? First thing I did was read the settings and save them - but some of this stuff looks Wrong.? (Example - "LSB calibration" is 0, but "USB calibration" is 11057115.? Not sure what these are...? Also, Si5351 I2C address is set to 0xff, while there's a warning in red which says "Warning: default value:0 or 0x60".? Worrisome!

Anyway, this brings me around to:? is there a repository for knowledge about this firmware and what all the settings are?? I found a "User Manual" for version 1.072, which helped, but the pieces I am particularly interested in are either not implemented yet, or just not written about.? (Example: how is the WSPR stuff set up and used?? I would love to know!)? ?I've looked around hamskey.com and ubitx.net, but it's all pretty fragmented.? Failing that, can anyone point me to threads here which would help?

I suppose if I need to, I can look through the source code, but I bet other folks have gone through all this before.? :)? Did I also forget to mention that I don't have a lot of direct experience with HF rigs yet?? :) :) :) It's also complicated by the fact that I live smack in the middle of San Francisco with all the noise that entails, so even with the antenna I've got set up (20m EFHW) I can't hear a lot


Thanks in advance,

+jeff AJ6IY