Thanks, Patrick, for your input.(posted 8240 days ago)I seem to recall reading (in the late 50's) that streaking was caused by a by-product of development, created by the silver-bromide/developer reaction, hence the phrase "bromide drag". Agitation was supposed to keep the stuff dispersed so it woudn't streak.
I saw no difference in streak patterns between the 120 and 220 reels. Other developers used over the years have never given me any indication that 220 reels are prone to uneven development.
What's really puzzling are the occasional streaks on the 8x20 sheet film. I tray develope one-at-a-time, being sooper careful to vary the agitation patterns. I'm pretty certain it's not an agitation problem.
I find Ryuji's comment about streaking being emulsion- dependant of interest. All of my "events" involved FP-4 and HP-5, whereas your recent test was with TMY. Ted used TMX and Delta films and saw no streaking. I wonder...could it be that these particular Ilford emuslions (FP-4 & HP-5) are more vulnerable to errant bromide, as mentioned above, and that the addition of Potassuim bromide, as suggested by Ryuji would help?? If I get a moment, I'll try a run with Ilford and Kodak films, with and without KBR.
By the way... why is your "My Favorite" formula (More Pyrotechnics Mar/Apr 2000 Photo Techniques) your favorite?