Here's a Usenet post that John made back in 2000:
" In my first test of TP in TEC, I followed the instructions and used
the higher dilution stated for TP; I got rather low contrast, speed,
and low D-max. This was with ordinary intermittent agitation.
For the second test I used the 1:15 dilution and got a normal (for
TP) curve shape and EI 50, which is two stops more speed than I get
for TP in any other developer for the same CI and curve shape.
This was certainly a surprise....so, suspecting an error, I tested
again and got the same results.
Subsequent usage (real photos) have shown my test results to be
valid.
TEC is intended for slow films; it came along in the days when
everyone was trying to equal 4x5 quality with 35mm using Panatomic-X,
Pan-F, the slow Adox film etc. There was much more "look how grainless
and sharp this is" than any interest in picture content. I'm glad
those days are gone.
This was long before anyone was using rotary agitation. Mechanical
agitation machines were goofy; there was even one that would invert a
standard steel tank.
The reason I mention that is that I believe TEC works just right on
the edge of exhaustion as a compensating developer; the very low D-max
obtained with the higher dilution of TEC appears to me to confirm
that. The edge of exhaustion isn't a comfortable edge to be dangling
over.
TEC in a rotary processor may not work very well; if it's diluted
too much it may oxidize too much, while otoh at sufficient strength to
avoid too much oxidization (brain fade; I can't recall the exact
spelling) it may give too much contrast.
I never tried it in a rotary processor. You're the pioneer, and you
know what's said about pioneers and arrows....
Data sheets for Ethol products are available from the distributor,
which I believe is still BKA. The Ethol data sheets I've seen are
pretty much a reflection of the old days, with greatly inflated EIs,
no curve plots etc."