so ive been messing around with an RTL-SDR v3 for about a year now and honestly its been a blast but im starting to hit its limits, mostly on the transmit side but also just noise floor stuff. looking at either a HackRF One or an SDRplay RSP1B and cant really decide which direction to go.

the HackRF is tempting because yeah obviously you can transmit on it, but from what ive read the receiver performance is kind of mediocre compared to dedicated rx-only stuff. the RSP1B seems way more serious on the receive end but then you're locked into SDRuno which i know some people hate. or i guess you can use it with SDR++ which is what id probably do anyway.

my main use is scanning anything from 137mhz NOAA satellite stuff down through HF and then occasional poking around at 433 and 915 ISM stuff. not really planning to transmit anything, im not even licensed yet, just doing a lot of listening and learning right now. does the RSP1B noise floor actually make a meaningful difference for satellite work compared to the dongle or is that kind of marketing fluff

the noise floor difference is real, not marketing. ran both side by side on 137mhz APT passes and the RSP1B pulls out cleaner images especially when the bird is low on the horizon. that said your LNA situation matters just as much - if you dont have a filtered preamp in front of the RTL dongle you're leaving a lot on the table before you even think about upgrading the SDR itself.

for HF the difference is pretty dramatic too, the RTL with direct sampling mod is workable but the RSP1B with its built in preselectors is in a totally different league. if you're not planning to transmit i'd honestly say skip the HackRF, the receive chain on that thing is fine for playing around but it's not what you want if you care about actually hearing weak signals. SDR++ works great with the RSP stuff now, havent used SDRuno in over a year.

i went HackRF and kind of regret it for pure listening honestly. thought id do more transmit experiments than i actually have. the rx noise floor is noticeable if you compare it to even a cheap RSP. for satellite stuff specifically you'll really want that extra sensitivity

one thing though - whatever you get, sort out your antenna situation first. i wasted months blaming my SDR for stuff that turned out to be a terrible coax and a dipole hung wrong. just saying before you spend the money