so i finally finished my first QRP rig, been putting it off for like two years because i kept telling myself i wasnt ready to build something from scratch. ended up going with the QCX mini kit on 40m and honestly the whole process was way more approachable than i expected. took me two evenings at the kitchen table with a decent iron and some flux and it just... worked. first time i keyed up i was genuinely shocked.

been running it portable the last couple weekends, just a random wire up in a tree and the built in ATU on my little KX2 to tune it and im getting contacts into the midwest pretty regularly from the northeast. running about 4-5 watts. i know thats kind of cheating since the KX2 is doing the matching but still.

anyway my actual question is about battery runtime. im using a 3ah lipo and it seems like im getting way less time than i thought i would. is that pretty normal for 40m ssb or should i be looking at cw more seriously. i mostly do cw anyway but sometimes i switch over. also curious if anyone has tips for keeping power draw down on receive since thats actually where most of my time goes.

yeah receive current is sneaky, a lot of guys dont think about it until they're out in the field wondering why the battery died. on the KX2 you can drop the rx backlight and also turn down the rf gain a bit when conditions are decent, that helps some. for the QCX mini specifically i think the rx draw is pretty low already, like under 150mA if i remember right, so that part should be fine.

the bigger thing with lipos is they dont like being run all the way down and they also sag under load on transmit so what your meter says at rest isnt the whole story. a 3ah pack sounds right for a good half day of casual operating if you're not transmitting constantly. SSB will absolutely murder your battery faster than CW because you're at or near full power more of the time. with CW and decent keying speeds you're probably at maybe 50% duty cycle at most, often less. so yeah if runtime matters, CW is genuinely just more efficient, not just a matter of preference.

also worth checking if the lipo is actually healthy. those cheap cells can lose capacity faster than you'd expect especially if they've been stored discharged.

the QCX mini is such a solid first build, good choice. im jealous you got it working first try, mine had a cold solder joint on the toroids that took me forever to find lol. midwest from the northeast on 40m at 5w is genuinely not bad at all, id call that a success.

on the battery question i dont have a ton of data but i switched to a bigger 5ah pack and just stopped worrying about it honestly. probably not the most elegant solution but it works for a day out