so i've been wanting to do this for a while and last weekend i finally got out there with my homebrew 40m DSB transceiver that ive been slowly putting together over the past few months. ran it off a 3ah lipo and a random wire up in a tree and honestly i was not expecting much but i worked 6 stations in about 2 hours which for 5 watts felt pretty incredible to me.

the rig itself is based on that W7ZOI design i found in the ARRL handbook, nothing fancy, just a VXO for the oscillator which means i'm kinda stuck around 7.030 give or take a bit but thats fine for CW. the whole thing fits in an old altoids tin basically, well the main board does, the PA stage and LPF are in a separate little enclosure i made from some scraps of aluminum i had laying around.

biggest thing i noticed is how much more you pay attention to propagation when every single db matters. like i was actually watching the greyline and thinking about where my signal might be going in a way i never really did with 100 watts. also realized pretty quick that my antenna situation matters WAY more than i ever appreciated before. had to retune like 3 times because the wind kept moving the wire around.

anyway just wanted to share because im pretty stoked about it and also curious if anyone else builds their own stuff and what bands you find most useful for portable QRP. thinking about doing a 20m version next but not sure if the extra complexity is worth it vs just sticking to 40m for parks stuff.

that greyline comment is spot on, that's honestly what got me hooked on QRP years ago. when you're running barefoot at 5w you start actually caring about stuff like that instead of just cranking power and hoping for the best. congrats on the first portable outing.

for 20m vs 40m — depends what you're going for honestly. 40m is great for regional stuff especially later in the day but 20m when it's open can be absolutely wild with QRP, ive worked europe from the midwest with 4 watts on a dipole and nearly fell out of my chair. the tricky part with a 20m homebrew is the LPF needs to be a bit more precise and your layout matters more at those frequencies, stray capacitance etc. but if you're already building from scratch you've clearly got the patience for it so i'd say go for it.

what did you use for your keyer? building or just a paddle into a standalone keyer?

this is so cool, im still in the reading-about-it phase with homebrew and stuff like this makes me want to actually just start. question — where do you get the toroids and stuff for the LPF? i keep seeing people mention Kits and Parts dot com but idk if theres a better source or if it even matters much for something like this