Ah, well ... so the very same thanks to Hans Martin, too - both of you are true pioneers !!!
Sorry - but with that huge amount of information here in this great forum I tend to forget some of it [:I]

Yep - #37621, A-B-A, 2 motors, 6090 Digital FX, 1997-1998

Yep that is the decoder I used. HOWEVER I think that the Part Numbers really refer to the Sound File Loaded. I have had no problems with driving the 2 Motors.

It is, but IMHO it's more likely that you may run into different running speeds of the two motors, since you will in fact have two different loks, knowing nothing of each other. If you use the same decoder, you'll be reducing the probability of trouble .

Hi all,

Connecting two dc motors in parallel to one decoder sounds primitive, but I think it is a very safe and intelligent circuit, as the motors tend to sync their revolution speeds. Impossible when each motor has its own decoder.

That's easy to see. Consider the case that one of the two motors has a higher revolution speed than the other, for some reason. As a consequence it generates a higher voltage across its brushes, and thus supplies additional electic power for slower motor. This slows down the faster motor, and speeds up the slower one, i.e. the faster motor works as a generator.
Well, that's a strongly simplified explanation, but mutual stabilization of two parallel dc engines is well-proved when e.g. combining several electric generators in power plants.

Hans Martin

As a matter of fact it does, albeit only as a spare part. One such example are the twin swiss loks, 37591 and 37593 and their decoders P/N 600597. They're big but I'm pretty sure you'll have the room needed in your basically empty F7. However, I see no need for such a costly solution, when you can perfectly use even a bog standard Lokpilot, not to mention a Märklin 60902. Rest assured it will work very well.

If you are really, really afraid of excess current draw, there's even another ESU solution for you a LokpilotXL or even a LoksoundXL. The LokpilotXL will actually fit in H0 loks, such as the F7 and many other big diesels and electrics. Not sure if the LoksoundXL will fit though. If I remeber correctly, the LokpilotXL is capable of handling 3 amps motors! Still, by all means use a standard H0 decoder such as the Lokpilot.

It's perfectly adequate, and you just have to connect the motors in parallel. As Hans explained, one will stabilise the other, and the result is a very strong and stable puller.

Ah, just rememebered another twin motor example: my turbine train, the BR602. It has a single, normal Loksoundmfx in it and it pulls like a horse.

Luis

It is. But do ponder the extra spending in an XL decoder. As I said the standard Lokpilots and Loksound will be more than enough. Still, if you're REALLY afraid of having a limit in the output current to your motors, the XL decoders are the sure way to go.

Good luck, and be sure to report on your efforts.

Luis

Hans Martin and I have done the F7 with only one Delta Decoder. Hans used the Loksound and I Used the MFX. as far as I can remember there was only one Decoder in the F7 from New.

Use the MFX Loksound Decoder

Thanks, Hans Martin - this is most interesting information
Reminds me a bit of "Das physikalische Gesetz der kommunizierenden Gefäße" ...

Hi Jon,

Installing a Faulhaber motor is indeed an interesting option. Old F7 will run like a Big Boy, I guess .

Hans Martin