so ive been doing single op contesting for a few years now mostly just casual stuff, NAQP and some state QSO parties, and i finally put together a second radio setup this past winter. been running a K3 as my main and picked up an used IC-7300 as the second. the antenna situation is... messy, a 40m dipole and a vertical that does 20/15/10 sort of okay.

anyway i tried SO2R seriously for the first time during the last sprint and i think i was losing more time than i was gaining. like i'd be in a run on 40 and then try to S&P on 20 with the second radio and by the time i found a mult or a new call i'd already missed like 3 or 4 guys calling me on the run frequency. is this just a learning curve thing or do people use some kind of footswitch or automation to manage the audio better? i was just manually switching headphone feeds with a toggle switch i built which is definitely not ideal.

also curious how people decide when to abandon a run and go search. my rate was decent but i feel like i left mults on the table by staying glued to one frequency too long. any thoughts from people who actually do this regularly would be helpful

yeah the audio management thing is really the first wall you hit with SO2R. what most guys do is get a proper SO2R controller - the MicroHAM stuff or even the older Top Ten Devices boxes handle the headphone mixing so you can have both radios in your ears at the same time, left/right or blended, and it also interlocks the PTT so you dont key both radios simultaneously and blow something up. doing it with a manual toggle is honestly asking for trouble and yeah youre going to miss callers.

the learning curve is real though, i wont lie. took me probably 4 or 5 serious contests before SO2R started actually helping my rate instead of hurting it. the trick during a sprint specifically is the second radio isnt really for finding mults, its for filling dead air. when your run freq goes quiet for more than like 5-6 seconds you work one guy on radio 2 and then come back. if you try to do long S&P sessions on R2 while running youre going to fragment your attention too much. sprints are brutal because the pileups move fast and people dont call twice.

the antenna isolation piece is something people dont talk about enough when they get into SO2R. if your two antennas are physically close or on adjacent bands with harmonics you'll get RF into the second receiver and it just sounds like a wall of noise. i had a similar setup to what you're describing and had to put bandpass filters on both radios before it became usable. the 4O3A or the Array Solutions filters are the usual recommendation, not cheap but kind of necessary if you want to run both simultaneously without one radio deafening the other.

as for when to leave a run, i basically watch my rate meter in N1MM and if i drop below maybe 60-70% of my average rate for that hour i start S&P more aggressively. but honestly in a sprint that calcualtion changes because the contest is short and mults are worth more relatively. i'd rather grab a needed mult and lose 2 minutes of run rate than finish the sprint one mult short.