i was looking at a video of the Rhaetian Crocodile Gauge G LGB and at one point the whistle gets triggered by a track magnet in one specific location.

is this possible with ho scale MFX locomotives? I am not talking about programming with the PC or with the CS3 but about a specific location that would always trigger the sound every time a loco passes it.

Thanks

CS3 for now with iTrain in the work (learning it), but I think the magnet is just an easy way to program a recurring event for all locos.

Hi
If you reject PC and CS2/3 solutions then you look for a now defunct Märklin system
Here is an extract of the Märklin 1970 catalogue

The principle was to add a frequency (5 kHertz or so) to the normal traction power
The sound was not convincing and the set-up was expensive so it did not last long.

Now, if you wan to use the sound in digital locos you need to have a device able to send a digital order to a loco. A CS2 or CS3 can do that but you need both the loco's address and the function number. This last one is easy if, using MAPPING you standardize the functions (e.g.: all whistles are on F3).
To know the loco number is more tricky: one or two locos: the CS2/3 can track the loco's position to know which to activate.
More locos: then you need a PC s/w like Rocrail as it follows each loco position and you can trigger the whistle (or any other fonction) of the loco located in the zone you wish
Sorry, I understand this is not the answer you were expecting.
Cheers
Jean

I am not rejecting PC or CS3 function nor do I want to purchase extra decoders since my Mfx locos already have them.

I was just wondering after looking at the video presentation of the G gauge loco having its horn blown of the decoder inside the loco by a magnet on the track if this was possible to do with HO.

Unless I am mistaken having the horn blown in a specific location with PC has to be programmed for every locos or remap function (why isn’t Märklin standardizing this?). This seemed a simplier solution.

Here is the video look around the 26:00 mark (beautiful model by the way)


Thanks JohnJeanB for your in-depth answer, I was aware of this but just wondering. I do hope Marklin will eventually implement locos location on track but I am aware of copyright problem with Rocrail (I believe)

Here, when one contact (s88) is trigerred by the loco (BR10 in this case) the signal turns red, the loco stop (no braking module), after a while it sounds the whistle and then start at a preprogrammed slow speed.
Of course you have to create events for each specific loco
Regards