so i finally broke down and ordered one of those QCX mini kits a few months back, mostly because i kept seeing people talk about them on here and i was curious. took me a couple evenings to put it together, nothing too crazy for someone who's done a little soldering before. anyway fired it up on 40m and made my first contact running like 3 watts and i genuinely could not believe it worked. the other station was in ohio, i'm in virginia, and he gave me a solid 559. i know thats not some incredible dx or anything but something about knowing you're only putting out 3 watts and someone across a few states can hear you clearly just kind of changes the way you think about rf.

since then ive been messing around more with antenna efficiency because i figure if im only running 5 watts i better make every bit of it count. been reading a lot about end fed halfwaves and whether the feedline radiation is actually a problem or not, still a little fuzzy on that honestly. mostly posting because i wanted to share the experience and also ask if anyone has tips for getting better results portable, like in a park or something. i have a little lipo pack i use for the radio but battery management for a whole day out is something i havent totally figured out yet.

congrats man, that first QRP contact really does something to you doesnt it. i remember mine was years ago with a homebrew 40m rock-bound rig and i think i actually yelled a little when the other guy came back to me. once you get that feeling you kind of stop caring about running a kw into a beam.

for the portable battery thing, honestly the simplest thing i've found is just getting a decent capacity lifepo4 pack, something in the 10-20ah range. they hold voltage way better than regular lipo as they discharge so your radio stays happy and you dont get weird behavior when the battery starts dropping. i use a bioenno pack and have literally spent all day in the field with my KX2 and still had juice left. also worth picking up a small usb power meter so you can actually see whats going in and out, helps a lot with planning.

the EFHW question is a whole rabbit hole, short answer is it works great if your 9:1 or 49:1 unun is decent quality. feedline radiation is real but usually manageable. plenty of people do sota and pota with them every day without issues.

I'm kind of in the same boat, just got my license a few months ago and have been doing POTA activations with a QCX+ on 20m. the kit building part is half the fun for me, sitting there with the instructions and soldering each component in knowing exactly whats in the radio is really satisfying compared to just buying a box off the shelf.

one thing I didn't expect was how much patience CW QRP requires, like you really have to be willing to call CQ a few times and wait. but the pileups when people are hunting you for POTA are actually kind of manageable at low power which is nice, not totally overwhelmed the way i imagine ssb would be. still figuring everything out but yeah the hobby feels way more real to me operating this way than it did just scanning around on a handheld.