so ive been wanting to do this for probably two years now and last weekend i finally just did it. built a bitx40 from scratch, well mostly scratch, took me about three evenings and one very late night with a magnifying glass trying to identify resistor color bands. the soldering on the toroids was honestly the hardest part for me personally, i kept second guessing how many turns i had done.

anyway got it all together, did the smoke test, nothing died, and i took it out to the park near my house with a random wire up in a tree and the little tuner i built from a kit a while back. ran it on a 3ah lipo i had kicking around from an RC car project.

made four contacts in about two hours, all on 40m, one of them was into ohio which from my QTH is maybe 400 miles? on 5 watts. i know thats not exactly DX but the whole thing felt completely different from sitting at the shack. something about knowing the rig came from a bag of parts and is now talking to someone 400 miles away. hard to explain.

the audio is a little bassy and the sidetone is way too loud, i have to tweak that still. but it works. anyone else do park portable QRP? curious what antennas people are using for this kind of thing because the random wire with a tuner feels a bit wasteful of the little power i have

that ohio contact on 5w from a homebrew rig is something to be proud of honestly. once you get a taste of it you kind of ruin yourself for the big radio stuff haha. i ran 5 watts from a summit in vermont last fall and worked a station in england and i still think about it.

for antennas in the park i really like a linked dipole if you have two trees roughly in the right place. cut for 40 and 20, just clip in or out the links, no tuner needed which keeps your losses down and when youre running 5w you really dont want anything wasting power in a tuner. the efhw transformers are also popular for this kind of thing and they pack down tiny, mine is literally in a film canister. takes a bit more fussing to get right but once you dial it in its great. the random wire with a tuner absolutely works but yeah like you said you are probably losing a watt or so in the matching network depending on how well the tuner is doing its job.

keep tweaking that bitx, mine went through like six different versions of the audio board before i was happy with it

wait you built a whole transciever and took it out the same week?? im still trying to figure out what kit to start with. did you have much electronics experience before or did you just kind of figure it out as you went? i keep reading about QRP and wanting to try but honestly the building part scares me a little