Thanks Bruce for mentioning the bad joints. For my own edification, would you be able to tell me (maybe by referencing the picture) which joints look the most problematic? I ask because I did inspect the joints, and while some of them looked a bit ugly I didn't see any that looked obviously bad. It's likely this is just because my eye for bad joints is not yet well-trained, so helping me find the bad ones would be a great help.
In general, is it possible to detect bad joints by checking continuity on either side of the board? Or are there issues that wouldn't be detected with this test?
I was not using a dummy load; I was using my multi-band HF antenna that should have low enough SWR on 20m. (I am aware this is generally considered bad practice; I don't have a good dummy load at my test bench, only an old ATU with an internal dummy load that is annoying to use. Clearly I should have gotten the QRP Labs dummy load kit along with the QCX+...) I'll re-run the RF power test with the dummy load and see if the numbers change substantially. I believe I correctly set the radio for 20m operation, but I will check again.
Ron, I will do those measurements tonight and reply here with the results. I did do the alignment procedures. The bandpass filter alignment tone is audible, but much quieter than the manual led me to expect. (I did not have to take my headphones off during the test.) The I/Q balance and high and low phase alignments do not seem very responsive to changes in the volume knob (or, for that matter, to turns of the screw on the variable resistors). After watching one of your YouTube videos about the QCX+, I tested the resistance across the three terminals of the volume pot; they seem to be correct.
One other piece of information that might be relevant is that I initially soldered the LCD screen to the front plate using the wrong nylon spacers, and so had to de-solder it, remove it, and resolder it. I used a plunger-type desoldering tool to remove the solder, but to remove the LCD and its pin headers from the plate I had to apply a good amount of force. After doing this, I found some brown material on the pins. Is it possible I damaged the front plate PCB contacts by doing this? Would this damage be detectable and/or fixable?
