so ive been doing contests for maybe 4 years now, mostly phone but getting more into CW lately, and every time i start reading about SO2R i go back and forth on whether its actually worth setting up for someone like me who isnt going to be doing a full 48 hour effort anyway. like i usually do 12-15 hours in a contest weekend, not really gunning for a top score just trying to improve my rate and work some mults i havent had before.

right now im running an IC-7300 as my main and i have an old TS-590SG sitting on the shelf doing basically nothing since i upgraded. obvious candidate for a second radio but the filtering and the antenna switching alone sounds like a project that could eat a whole weekend just to get the RF isolation sorted out. heard people talking about needing like 60-70dB of isolation between rigs or you just trash both receivers the second you transmit on either one.

is there a point where you're operating enough hours that SO2R starts paying off in terms of rate, or is the real gain just in the mult hunting while you run on the other radio? curious what people actually find in practice vs what the theory says

honest answer is that for 12-15 hour efforts the S/O 1 radio game is probably where most of your rate gains are going to come from before you even touch SO2R. like are you using a DVK and CW memories to minimize your turnaround time between QSOs? are you tail-ending runs properly? those things compound way more than people realize before they go chasing the two-radio setup.

that said, if you already have the 590 sitting there, the mult-hunting application is genuinely useful even at casual effort levels. you keep running on radio 1 and use radio 2 to check the bandmap for mults without ever stopping your run frequency. you dont even need full SO2R technique for that, just decent isolation and a way to monitor both receivers. the antenna switching is the annoying part yeah, but a used W2IHY or even just a good 2x4 switch and some relay logic isnt that crazy to put together. the 60dB isolation thing is real though, dont underestimate it, i blew a front end on a borrowed radio years ago being dumb about that.

i went through exactly this debate last year and ended up doing a hybrid thing where i set up the second radio just for receive monitoring during runs. wasnt doing true SO2R transmit switching or anything, just had the second rig on headphones in one ear so i could hear whats happening on 15 while im running 20. felt like cheating honestly, rate went up noticeably in the CQWW because i could flip over and grab a run frequency on 15 when conditions shifted instead of losing 10 minutes hunting around blind.

full SO2R with interlock and all that, i dont know, seems like it takes a while before the technique becomes natural enough that you're not actually hurting your rate by fumbling the switch timing. might get there eventually but im not there yet