I put up a new antenna for ISS work today. It's a home-built 2m turnstile with reflectors. Numbers wise (SWR, etc., as read on a MFJ analyzer) the antenna is working. I used the antenna a bit on APRS and was able to hear stations and be heard by stations.
I listened to the ISS for 3 passes earlier today. On the first 2 passes I heard a number of stations, but was unable to digi via the ISS. On the third pass (about 40 degrees elevation at max and to the south), I was able to digi via the ISS (sorry if I have the terminology wrong here, I'm somewhat new at this).
My question is, how often should I be able to digi via the ISS? Is it unusual to not be able to on a given pass (all 3 passes were higher elevation passes)? I know there are collisions and QRM involved and someone wins out. I don't have the best station (IC-706MKIIG and a turnstile antenna), I'm sure this plays a part.
Curious what others have experienced.
Thanks,