Hi Roger, I don't see any 3600's in the 1935 catalog, but I do in the 1936 "OO" catalog (I think OO was introduced for the first time in 1936); however, there are no "AR" pieces.

Is it possible the "R" is a smudged "A"? That would correlate to the "Anschluss-Schiene" (Connection-Rail) 3600 AA in the 1936 catalog

It wouldn't have had a red plastic connector as in 1952+, and it would be male.

I hope this helps.

Brian

Roger - it is 3600 AR.
In the early days of 00 around 1936 the controllers used only had four output voltages so there was no fine control of the locomotive speed.

This power feed track has a small wire wound resistance underneath it and the red knob moves a wiper over the windings. It allowed a limited amount of speed adjustment so the speed could be fine tuned between the coarse speed steps of the main controller.

Google Marklin 3600AR and look at images and you should see a picture of the underside of it.

It's very rare apparently as it was not required once better main controllers became available so was only in the system for a year or so.

Paul

Your welcome Brian.
This has got me thinking now....
On traditional analogue layouts they would be quite useful for feeding power into short adjustable slowing sections before signal stops as they could be quickly adjusted for faster or slower locos.
Also they could be useful for feeding into downhill sections to prevent the trains racing down the hill. Again the knob could easily be adjusted for different locomotives.
It would be a nice little project to make a few.

Paul

Thank you, Roger. This is why I love this Forum.

While low voltage compared to the mains, regulating the return is somewhat scary since an accidental short from the center rail to the return plug on the trafo could be a surprise, as unlikely as that would be. Certainly not as bad as a wall switch being used on the neutral wire (my first home, wired in 1917, had that but not for long after 1987 upon my purchase...)

I need to read tischbahn more often!

Brian