Guus, Tom, Lutz and Perz:
Thanks for your replies and explanations.
I am happy with my 39820. It is running OK, with no jerks or other problems related to voltage drop, even when operating other 3 Locos in the layout.
So, no trip to Germany.(For my 39010, it took 4 months the all around trip from my country to Germany and return....too much time).
Julio

I have done a test with my 39420 SBB Re 4/4

When driving the locomotive and one coach (the 49960 Messwagen), with other locomotives (two big steamers, a 3044 and a 36320) parked on the test layout, the average current is 510 mA.

First of all, I notice that the locomotive speed is very variable. I try to keep 80 km/h, but the speed is varying between 76 and 84 km/h. Also the current is changing quite much all the time. From 483 to 534 mA, but mostly between 503 and 517 mA

Turning one smoke generator on (on a parked locomotive), the current increases 100 mA an is still varying a lot. The locomotive speed drops approx. 10 km/h

Turning a second smoke generator on, another 100 mA is added to the current. The locomotive speed drops another 4 km/h.

All the time the speed changes, basically approx. 4 km/h up and down from the avarage speed.

Except from the varying speed, the locomotive runs very smoothly and quiet.

As Lutz stated, the HWZ 26610 are now being "upgraded" (to the new quality standard). Mine has arrived at my German dealer and is waiting to be shipped home to "daddy".

/Torbjörn

When I look at the setting of the original decoder for my 39420 SBB Re4/4, I find this:

Load Control:
Reference parameter 0,000
Control parameter K 0
Control parameter I 0
Control influence 0

I have no idea what this means, and I see the same data on the catenary maintenance vehicle, 39970.

Can these settings have any influence on the varying speed that has been discussed earlier?
Should I try to change some of them?

Understood, Lutz.

Thank you.

Henschell Wegmann is back and is the way I expected it to be 3 years ago when I bought it [}:)]

Anyway, it is perfect and runs beautifully smooth.

This does show that, one way or the other, even if later rather than sooner, Märklin stands by its products.

I think that they did this the way they did probably because they know their customer base. Maybe 50% static collectors, 25% occasional runners, 25% frequent runners.

Of these, the static collectors will never notice any issue, half of the occasional runners will notice and the frequent runners will notice. This way, only 37.5% of the loks will be returned, minimising costs. And this has happened before, I remember the first 37555s with non-load compensating decoders that were exchanged IF you complained, just like this case.

Right, Luis - they easily could sell them dummies with a junk of lead, inside [}:)]
What waste of motors, gears, and decoders. And Svein's orange wire ...

Just got mye model 39619 in the door after the SDS upgrade

Really looking forward to test it this weekend as it was not running well before

I asked M* about my BR 151 (#39582).
They replied today and told me to phone them in four through six weeks.
I presume that also applies to other locos with mfx and original c-sine motor.

Thank's Per

Old big C-Sinus motor and mfx doesn't really work 100% after my experince either [:I]

So my model's with the old big C-Sinus has either the 6090x type decoder or I have changed the motor to 5-pol to use mfx and sound