Any Difference Between Jobo 25xx and 28xx?

[RedSun]

If they are of the same size? I believe they are of the same diameter?
My 2840 is mounted on a 2521.

[ic-racer]

2800 has ridges inside to allow paper (and sometimes sheet film) processing.

[RedSun]

Then, would the 2509 fit the base tank? Or it is too large?

[Sevo]

28xx and 25xx are the same diameter, and will both take 2509's (provided that the rest of your kit has enough of the required axles and a 25xx type lid). I've always mixed and matched mine when it came to film on reels. The one restriction is that the 25xx drums usually have none of the ridges to attach the paper stop clips to (Jobo sometimes seem to have shipped 28xx parts as 25xx, so YMMV), so they cannot be used for several large wall-mounted sheets in one go. Rule of thumb: If you buy drum extensions, pick the 28xx of the desired size and it'll be good for either purpose.

[RedSun]

This is good to know. It appears the 25xx normally come with cog lids and 28xx with regular lids.

[Sevo]

That is no lid code, but must be a peculiarity of your local market. The lid and coupler type used to be encoded into the last digit - 3 for cog, 1 for plain lid with base magnet, 0 for plain lid and no coupling.

Fifteen years ago the relations were the other way around from what you seem to encounter now - the bulk of (25xx) film drums sold with cog (corresponding to the dominance of lift systems and ATLs in advertising photographers in-house E6 labs) while the less widespread (28xx) paper drums mostly attracted a Ilfochrome, black and white and alt process crowd that had much less use for lifts and cogs due to cross-pollution issues.

[RedSun]

The CPA/CPP manual I have has the 25xx with cogs and 28xx with caps, all of them.