so ive been contesting seriously for maybe 3 years now, mostly CQWW and SS, and i keep reading about SO2R being this massive rate multiplier but every time i try to actually run it i feel like im just making a mess of both radios instead of actually working stations efficiently. like i get the concept, run on one radio, S&P on the second while the other is in a lull, but in practice my brain kinda falls apart around hour 6 especially when the pileups get heavy.

currently running a K3 as my main and i borrowed a friends FT-991 for the second radio last CQWW but the intermod between the two was pretty rough even with bandpass filters, i think the issue was i was too cheap to get the proper 2-radio setup with the RX antennas separated properly. or maybe my station just isnt laid out right for it. anyway the rate i was getting didnt really justify the headache.

so whats the actual learning curve look like for people who got SO2R working well? and is there a threshold like number of contacts per hour where single radio just kind of plateaus and SO2R is the only way to push past it? just trying to figure out if i should invest more time into this or focus on other things like better antennas or improving my CW speed

honestly the intermod thing you mentioned is probably 80% of your problem. if the radios are bleeding into each other you're fighting a losing battle before you even start thinking about operating technique. proper bandpass filters, a good 2-radio controller like the MicroHAM or the homebrew stuff using the shift registers, and seriously separated antennas make a huge difference. i was running into the same thing until i got a dedicated rx antenna on the second radio just for S&P and it changed everything.

as for the skill curve, yeah it takes a while. i'd say it took me maybe 4 or 5 serious contests before i stopped actively making things worse with the second radio. the trick that finally clicked for me was treating SO2R less like multitasking and more like a rhythm thing. you're not really running both simultaneously, you're just filling dead air on radio 1 with radio 2 activity. once you stop thinking of it as two radios and more like one radio with an opportunistic side channel it gets easier.

the plateau question depends a lot on conditions but yeah above like 150-160 qph in a major contest single radio starts to hit a ceiling pretty hard especially during the slower periods.

the FT-991 as a second radio is kind of a rough choice for SO2R just because the front end isnt exactly known for handling strong adjacent signals gracefully. not knocking it for general use but when you've got a running station hammering away on 20m and you're trying to pull weak ones on 15 with it sitting a few feet away, yeah thats gonna be messy regardless of filters. something with a better roofing filter situation would probably help a lot if you're serious about pursuing it.

that said i kind of agree with taking a step back and asking whether the antenna situation is sorted first. ive seen guys with SO2R setups that were technically impressive but their antennas were so mediocre that a single radio op with a good yagi was still beating them. rate optimization kind of assumes you're already competitive on the RF side, otherwise you're just optimizing a weak signal problem