I have just gotten my BITX40 fully up to date for V 1.27.6 and have loaded that sketch. All features work as advertised, and I even put in my Call Sign into the version I loaded, which also worked. I implemented the Capacitive touch plates and that works as well. But, I do have a few problems for which I would appreciate some insight. I am an old EE/Systems Engineer with lots of analog/digital/software design experience, so I am able to implement and test pretty much everything coming down the pike. I haven't branched out on my own yet, i.e., made major changes in either hardware or software, but I have lots of ideas, which is the point. So here are my current issues:
1. Even with the volume turned way down (not related I guess), the CW side tone coming through my earphones (haven't installed speaker yet) is way too intense. I implemented the 47/1k connection from the audio amp and Raduino D5, and I guess I can figure out how to attenuate that signal, but why? It is coming from the Raduino which should have a way to attenuate one way or the other, yes?
2. Receiver noise is horrible with no input from an antenna (50 ohm dummy load or just open). I have implemented the LM386 suggested mod and another mod to better meet FCC requirements. As I understand it, the BITX40 should be very quiet with no antenna input. Perhaps one of the IF stages or the RF stage is not working properly? I was listening tonight with my antenna hooked up and I certainly could hear CW (with noise) and also SSB QSOs going on, but the signal to noise ratio was terrible. Atmospheric conditions are probably not good especially at night, but my Yaesu HF rig was much quieter. I also ran into what seems like a lot of birdies across the band (compensated drive for the one at 7.199)