so i finally finished my first scratch built QRP rig, been working on it for about 3 months on and off. its a single band 40m CW rig loosely based on the Pixie design but i made some changes along the way mostly because i couldnt find the exact parts. ended up with somewhere around 500mw output which i know isnt much but i was honestly just happy it made any RF at all when i first keyed it up.

got my first contact with it last weekend, guy in ohio, im in michigan so not a huge distance but man it felt like i worked dxcc or something. the whole thing runs off a 9v battery and i took it out to a park with my end fed wire and just sat there for a couple hours calling CQ and working a few stations.

couple things im not sure about tho. my sidetone sounds a little weak and i cant figure out if thats a component value issue or something else. also im getting what sounds like a slight chirp on my signal, had one guy mention it. i think its a power supply stability thing but im not sure. anyone dealt with chirp on a homebrew rig before and found a fix that actually worked? dont want to add a ton of complexity but also dont want to be that guy with the ugly signal

chirp is almost always a keying issue on simple rigs like that, the oscillator frequency shifts a tiny bit as the key goes down because the supply voltage dips or the transistor loading changes. easiest thing to try first is a bypass cap right across the oscillator supply line, like a 0.1uf ceramic right at the transistor. sometimes people also add a small buffer stage between the oscillator and the PA so the load changes dont pull the frequency around. on a pixie style design its kind of baked into the simplicity of the circuit honestly, you may not get it totally clean without some rework but you can usually get it much better than stock.

congrats on the first contact with a homebrew rig by the way, that ohio contact on 500mw is actually pretty solid. 40m can do surprising things especially in the evenings.

ive been doing qrp portable stuff for a few years and the chirp thing drove me nuts on my first build too. what worked for me was a small regulator on the oscillator stage even if the rest of the rig runs straight off battery. like a 78L05 or similar just for that part of the circuit. keeps the voltage rock steady when you key down and the current draw spikes. total overkill maybe but my signal cleaned right up.

also the park operating thing is so underrated, theres something about sitting outside with a tiny rig and a wire in a tree that just feels like what ham radio is supposed to be. keep at it