so i finally finished my first QRP rig, been putting it off for about two years honestly. went with the Michigan Mighty Mite as a starter since everyone said it was hard to mess up. got it oscillating on 40m and made my first CW contact with it last weekend running somewhere around 500mw i think, maybe less. the other station was only about 200 miles away but still, it was MY radio that i built with my hands and that felt incredible.

anyway i have a few things im trying to figure out now. first, the output is drifting quite a bit when it first fires up, like maybe 500hz or so over the first 10-15 minutes before it settles down. is that just the crystal warming up or should i be looking at something else. second question is about antennas — right now im just throwing a wire up in the trees and feeding it with some coax and a tuner, but i keep reading that for QRP you really want a better antenna situation than you can get away with at higher power. is that actually true or is it overstated. been thinking about building an end fed half wave but not sure where to start with the matchbox. thanks for any input

the drift you're seeing is almost certainly the crystal warming up, totally normal for that circuit especially if you didnt add any kind of enclosure or thermal mass around the xtal. some guys wrap theirs in a little foam or even just let it live inside a small tin to keep the temp stable. after a while you kind of just know to key up and let it sit for a bit before calling CQ. mine used to drift like crazy until i built a simple little wooden box for the whole rig and it helped a surprising amount, probably just keeping drafts off it.

on the antenna thing — yeah its not really overstated unfortunately. when youre running a watt or less there's just no margin for sloppiness in the feedline or a mediocre antenna. every db matters a lot more. the EFHW is a great choice for portable stuff, the matchbox is pretty simple to wind, 49:1 transformer is what most people use. look up the QRPguys EFHW kit if you want a reference design, even if you dont buy it the schematic is worth studying.

congrats on the first contact that's awesome. i just want to say the Michigan Mighty Mite was my first build too like three years ago and i had the exact same drift thing going on and kind of panicked thinking i did something wrong. you didnt. its just how that circuit behaves. once it warms up its actually pretty stable for what it is.

i cant really speak to the EFHW stuff yet im still figuring out antennas myself but i will say i upgraded from random wire to a simple dipole cut for 40 and it made a noticeable difference even at QRP levels so any improvement you make to the antenna will probably pay off fast