so i've been wanting to do this for a while now and last weekend i finally just did it. built a little pixie kit a few months back but never really used it much, then last week i put together a basic 40m direct conversion receiver from a design i found in an old QST issue and paired it with a small transmitter board i ordered from one of those overseas kit sites. whole thing runs off a 3ah lipo i had from an RC car project and fits in an old metal tin i found at goodwill.

took it to the park on saturday morning with my end fed wire thrown up into a tree, maybe 30 feet up, and just started calling CQ on 7.030. wasn't expecting much honestly, i mean its like 3 watts into a not great antenna and im running this janky homebrew rig that i half expected to smoke when i keyed up the first time. but i made 4 contacts in about an hour, one of them was a guy in nebraska which blew my mind because im in tennessee. i know thats not crazy DX or anything but for 3 watts and a kit antenna out of a tin box i was pretty stoked.

the whole experience kind of reminded me why i got into this hobby in the first place. like sitting in the grass with headphones on, the sun coming through the trees, doing morse code with a little brass straight key. just felt right you know. anyway i know a lot of people here do QRP stuff so curious what rigs you guys are using when you go portable. also any tips on squeezing more efficiency out of a simple transmitter circuit would be appreciated, i think my final amp is running pretty hot.

that nebraska contact on 3 watts from tennessee on a homebrew rig is honestly a great first outing, dont let anyone tell you otherwise. 40m in the morning can really surprise you when the band decides to cooperate.

for the heat issue on your final, first thing id check is your load matching - if the output impedance isnt right you can end up dumping a lot of power as heat instead of RF. a lot of those cheap kit transmitter boards have a pi network but the component values can be off from what you actually need for your antenna. worth putting a cheap watt meter inline if you have one and seeing how much power is actually making it to the antenna vs whats going in. also check the transistor spec, some of those boards use devices that are technically rated for the power but just barely and they run hot by design. a small heatsink even just a little clip-on one can help a lot. i had the same issue with a 40m transmitter i built a few years back, ended up being that the trimmer cap in the tank circuit was way off and once i tuned it properly the transistor went from too hot to touch to just warm. good luck with it and keep going portable, its really the best way to operate imo.

this is making me want to get back out there, havent done a SOTA or parks on the air activation in like 6 months. i use a KD1JV designed rig i built a while back, runs about 4 watts and its stupid efficient on battery. i can run it half a day off a small lipo and barely dent it. the thing about QRP that people dont realize is its not really about low power being a handicap, its more like it changes how you operate. you actually have to think about band conditions, time of day, antenna placement. when you have a kilowatt you can just sort of brute force contacts but QRP you actually have to work for it which is way more satisfying when it works.