so ive been running an RTL-SDR v3 for about two years now mostly on VHF/UHF stuff, airband, some P25 trunking with DSD+, the usual. works fine for that. but lately ive been getting more into HF and the RTL just doesnt cut it below 30MHz even with direct sampling mode enabled. its okay for a rough look around but the dynamic range is garbage and i keep getting images all over the place especially around the AM broadcast band.

anyway ive been looking at either going the HackRF route or picking up an SDRplay RSPdx. the HackRF is tempting because you can transmit with it (even though im not planning to do that anytime soon, still nice to have) but from what i can tell the receiver performance is pretty mediocre compared to dedicated rx-only hardware. the RSPdx seems like it has much better specs - 14-bit ADC, decent noise figure, the notch filters for MW and FM broadcast which would really help my situation.

the price gap isnt huge, maybe $50-80 depending where you buy, but im trying to figure out if the RSPdx is actually meaningfully better for HF listening or if im just reading marketing material. SDRuno is also kind of whatever from what ive heard, though i know you can use it with other software too. anyone been down this road and have an actual opinion on it?

had both at one point and honestly the RSPdx wins for HF, not even close. the HackRF is neat hardware if you want to do tx experiments or just play around, but as a straight receiver its kind of mediocre. the noise floor is higher and you really notice it on weak signal HF stuff. the 8-bit ADC hurts you when you've got strong broadcast stations nearby cramming into the front end.

RSPdx with a decent LNA and a random wire outside did more for me in one afternoon than months of tweaking the RTL. SDRuno i actually dont mind, it took a while to learn the layout but the IF bandwidth options and the bias tee control from software is handy. that said i mostly use it with SDR++ now because the interface is just faster to work with. you can pair basically any SDR with SDR++ or GQRX and be fine.

the MW notch filter on the RSPdx is not a gimmick btw. i live maybe 2 miles from a 50kW AM station and without it the whole HF band was basically unusable. with it on, problem mostly goes away. worth the price difference for that alone if you're in a similar situation.

if transmit capability isnt a real need then dont buy the HackRF for HF rx, youre paying for something you wont use and getting worse performance in the thing you actually care about. the ADC depth matters a lot on crowded HF bands.

one thing nobody mentions - the RSPdx has three antenna ports with different input characteristics, the high-z port for longwires is actually pretty useful if you dont have a proper 50-ohm antenna. small thing but i use it.