Hi SBNY99 (a first name would be great)

I use 24997 for quite a while and they work quite well but have limitations:
- they include a thermal protection unit (will switch off if operated for too long)
- they work well on both Relex and short couplings (KK) PROVIDED the couplings are not in tension (not pulling the train but rather pushing it)
- when operated automatically the best is a short couple of activations
- some Märklin locos make the uncoupling almost impossible (snow blade, etc)
- combinations of old Relex metal couplings and new KK may cause problems, especially if the metal hook is bent too much inside
- height of couplings must be verified as, some cars may have a very low coupling.

Here is an automatic Hump yard on my layout to illustrate this using Rocrail and an home made IR beam to detect the couplers

I have five 24997 uncouplers, all operated automatically all work very fine but, sometimes are very noisy.

Cheers
Jean

Hi Scott
I think there is an issue with the uncoupler or with its control unit.
Does it dol the same when you connect it directly to the transformer or the rectified digital power?
It lokks like there is a bad connection somewhere.
Cheers
Jean

I am not sure why but my 24997 uncouplers are much louder. There is a lever on the side of the 24997. Have you tried operating it to see if it uncouples cars? And have you checked the voltage? Perhaps the setting is too low?

Hi
It is by gravity (2% grade) and a precise uncoupling moment whch push the wagon away
Jean