so ive been running SO2R for about three contest seasons now and im still not sure im doing it right. last weekend during the state QSO party i had my second radio parked on 15m while i was running on 40 and honestly i think it cost me more time than it saved because i kept losing my run frequency when i'd go answer something on the second radio and come back to find someone parked on my spot.

my setup is nothing fancy, two K3s with a bandpass filter setup between them, dipoles at different heights so the isolation is decent enough that i can usually transmit on both without too much bleed. but the operating strategy side of it is where i feel like im still fumbling. like when do you actually commit to a second radio CQ vs just doing S&P on it when you hear something good. i've read the k1ar stuff and the n5kf writeups but some of it feels like advice for guys running at 200/hr rates which i am definitely not doing.

anyone who's actually ground through this and figured out when SO2R starts paying dividends would be great to hear from. im averaging maybe 80-90/hr on a good run, is that even fast enough for SO2R to matter or am i just adding complexity for no reason

honestly at 80-90/hr SO2R is probably still worth it but the payoff is more about multipliers than raw rate at that speed. when your run frequency is cooking you really shouldnt be touching the second radio much at all, maybe just a quick scan to log a new mult if you spot one. the real value comes during the slow periods, like when 40 starts dying before sunrise and you're trickling calls — that's when you work the second radio harder and keep your overall rate up instead of just sitting there calling CQ into the void.

the losing your run frequency problem is real and never fully goes away. some guys set a really short CQ repeat rate and just blast the call every 4-5 seconds so people know the freq is occupied. others just accept it as a cost of doing business. i've started dropping my power a tiny bit on the run radio when i go to the second radio just to stay in the exchange faster and get back before someone squats on me, not sure if thats actually helping or just superstition at this point

the bandpass filter isolation question is actually the thing that bit me worst when I first tried SO2R. I had what I thought was decent isolation but I was getting enough IMD from the second transmitter that my receive audio on the run radio was getting crunchy during exchanges and I was copying calls wrong which killed my rate way more than any strategy mistake. worth doing a proper isolation test before your next contest if you havent, just key up one radio and listen carefully on the other at various power levels. you want at least 60-70dB between them depending on band separation.

on your actual question about when it helps — i think the honest answer is it depends a lot on your antenna situation more than your operating speed. if your antennas have really different takeoff angles or youre on bands that have genuinely different propagation windows then the second radio is finding contacts that just arent available on your run band at all. thats free points. if youre basically pointing two similar antennas at similar paths then yeah you're mostly just making your life harder