So I just changed from ICU to IR this year and am taking call for the first time. We have 8 RNs in our department, 5 Rad Techs.
Because we have 8 nurses, we each take call every 8th weekend (Friday 5pm - Monday 6am), and 1 holiday per year. The Rad Techs are more on frequent call since there's fewer of them.
Every 8 weeks I have 6 weekday evenings of call (5pm - 6am), so I have 2 weeks out of every 8 with no call at all. I never have more than one weeknight per week unless I pick up someone else's call.
Rad Techs get called in for everything we do except paracentesis & thoracentesis procedures, those are MD & RN only. If it's just a bedside central line placement in off hours, the RN has the option to not come in.
I've only been doing this 4 months so far, and the times I've been on call, I'm more likely to have to stay late and finish up late cases. I've only had to come in at 3am once.
We do IR, CT procedures, Ultrasound, and Xray procedures (mostly LPs) and we don't get called in too often. Call pay is $2/hour and if you get called in, time and a half, for a minimum of 3 hours worth of pay, even if you don't work the full 3 hours.
Edited to add - We are not yet combined with Cath Lab/EP but we will be in a few years. Lord only knows what will happen to call when that happens... We are a stroke center, but we do not do any interventions in our IR above the clavicle basically. My only 3am call was CT guided neph tubes for hydro. Some weekends nothing happens at all, and some weekends you're there the whole time, but at least it's only every 8th! They try not to call us in if it can wait until the next day.