So, I just installed the new QRP-Labs AGC board and the new 1.08 firmware chip in my QCX-Mini 20m rig.
It works as advertised! I'll still be adjusting it a bit, because it works *so* well, based on the adjustment instructions in the manual. With the volume turned all the way up, I am not blowing out my eardrums, which is nice.
I did have a couple "gotchas" I had to fix before everything worked as expected:
1. I apparently shorted something to ground while doing the install. When I first powered everything on, it was transmitting dits. I looked over everything, and I couldn't *see* a short anywhere, but I knew there had to be one. I re-worked and cleaned up the connections on the bottom of the board, and then all was FB.
2. I forgot to reset the reference frequency for the TCXO, if you've installed the new firmware chip. Until I did that, it was set for the factory default crystal. I thought I had deafened my Mini until then. So don't forget that. Once I set the TCXO ref freq, I was able to receive stations again without issue.
3. RX audio was *super* quiet, even on what I confirmed on a different radio as a "strong" signal (e.g., an S5 signal on my 7300 was registering as barely above the noise floor on my mini). Turns out, this was user error. I "solved" a problem wherein sidetone audio was distorted by reflected RF, by adding a 104 capacitor across the audio output. The mod I did was... somewhere on the QRP-Labs sites or this board... I couldn't find the link. But, either way, once I removed that capacitor, my audio levels were fantastic with the new AGC board in place. I haven't yet checked if I still get an RF problem with an end-fed wire antenna out in the field, but I'll do that soon and update here. The moral of this story is: double-check that any mods aren't interfering with the addition to the circuit.
Anyway: the point of all this is to say thanks to Hans and team for another great addition to an already feature-filled radio! I was talking with a couple radio buddies about this new little module, and they're all impressed. Hopefully, that'll turn into some sales for you!
73,
Chuck KI5JUB
Chuck AI5LC