Lee, that is interesting about the flow pattern with the 2509 original reels and the later with the clips.
Mick,
I purchased the CPE-2 when I was in Germany for a year in '82-83. Our landlady said I could develop film in the bathroom when we made our arrangements. After my first roll of film, she said I had to use the unheated basement. So I was forced to do something like the CPE-2 in order to develop film at all. The CPE-2 produced flow marks on 35mm, 120, and 4x5 using the developers I tried, which would have been Rodinal 1:100 and HC-110. This was when Jobo was recommending the slow rotational speed and not mentioning the 5 minute presoak they came up with later. I also tried the 4 sheet arrangement you use. Within 18-24 months Jobo were pushing a new processor and tanks, another $1500 minimum investment as the way to be assured of highest quality 4x5 results. In the meantime, after 4 months, we got a long delayed first paycheck from the German university system and moved to a place where I had a heated bathroom to work in. I never found the Jobo worth pursuing for film after the initial poor experience. It was great for color printing with Cibachrome and Kodak EP-2 materials later.
Years later, when checking on the internet, I found that Jobo had changed all their recommendations, fast rotational speed, minimum 5 minute presoak, a new reel 2509N with the deflector/retainer clips, and they redesigned the spiral reels as well. Mine just have radial spokes, no solid spiral channels, and those produced standing waves at slow speed, clearly visible as flow marks on 35mm and 120, with varying spacing with the widening radial spoke spacing between the inner and outer parts of the reel.
I did a quick experiment with Rodinal 1:100 a couple of years ago, Pan-F replacing the original Panatomic-X, Rodinal 1:100, same reels as before, but with the 5 minute presoak and faster rotational speed recommended a year or two after I got my setup. Those negatives came out fine. But with a heated darkroom, I just do stainless hand tanks because the setup, breakdown, drying, etc involved with the Jobo is too much bother, and I don't have enough room to leave it in a state of readiness.
I'm not anti-JOBO. I just had a combination of early, insufficient instructions, and bad luck with my chosen film/developer combinations in a system that I was "forced" into buying by circumstances beyond my control. In the days before the internet, keeping up with these sorts of issues was tougher. I also bought in Germany and moved back to the US, so I wasn't registered with Jobo USA and didn't get the newsletters they were sending out that addressed all these issues. Other folks obviously have had great success with the system at all stages, and the same kinds of vagaries are also rife with hand tanks, as the many threads here on APUG show. I still have to think that others were having the same issues as I had, given the design changes to the reels and the changed recommendations for presoak and rotation speed. BTW, Jobo USA was great about advice and supplying me with the proper transformer, fuse, and heating element as parts to convert my CPE-2 to US AC power myself.
Lee