Hi
Definitely your model is a FX one with standard motor.
It is not described as a high efficiency motor (HLA HochlLeistungAntrieb) so I believe there is no regulation (because of the simplified Fx decoder.
One aggravating factor may be the use of a transfo to feed the 6021 (but you have no choice with the 6021).

The result is that the rectified voltage fluctuates with the load resulting that even on the best regulated engines there are speed fluctuation coming from input voltage fluctuations.

Clearly on a recent MFX loco, with a switched power supply with CS2, CS3 there is clearly a good regulation at play where no matter the incline up or down, the speed remains the same
Cheers
Jean

No, it would not.
Most (Märklin also) transfo have a voltage that changes with the load, up to 10% or more.
Switched regulated supplies have a DC regulated output (on mine typically 19.2 to 19.4 VDC)
The result is the envelope of the digital signal stays always with the same voltage.
This is a MUST for a regulated propulsion to be effective.
If you take a very well regulated loco but have a fluctuating input voltage to your digital system, the speed will vary.
Cheers
Jean

IMO you have to change your digital unit (CS2 or CS3 powered by a regulated switching supply such as the 60041, 60045 or 60101 (depending on your country).
It may be OK to use an MS2 with its power supply, but on this one I cannot say for sure.
On my layout I have a CS2 with a 60101 power supply from 2012.
Inclines are no bigger than 3% trains are no longer than 1.7 m and on my layout I never had to speed adjust because of incline (all my locos are MFX with HLA motors.

Jean

Wow Jean I must very impressive layout you got a lot going in a single space.

According to the product DB the train has load regulation. That should also work in analogue operation.

You may have to reduce the maximum speed of the train using the pots because the decoder needs a reserve to get the load regulation working.

Hi Waterslip

Seeing your video brought me back when I was running analogue Märklin.
It also made me understand I owe you an apology:

• I have not tested all my digital trains in analogue mode recently so I cannot tell really how they behave with AC. It could very well be that most speed and traction regulation is gone in analogue mode. The excuse is now we all know it is best to avoid ruining a 110$ sound decoder
  
• I forgot (but thanks to you now I remember) that in analogue mode, it was really necessary to have sections with elevated voltage for uphill and reduced voltage for downhill.

So apologies and there is a real strong case for going digital
Cheers
Jean

Hello friends,
So I just got my 6021 controller and connected to the layout, ran the loco uphill at minimal speed and it worked perfectly, very smooth uphill climb and well regulated.
Thank you fkowal for pointing it out.