Here is some of the speakers I have used in some of my conversion's.

The first 2 is speakers from Märklin while the other 3 is from ESU.

The Br.23 (39230) with Telex coupling on the tender:

I had seen this model on the German Stummi-forum. A member there had installed red tail lights in the tender. When checking a little bit closer on the tender I saw that it has the same coupling mechanism as many of the bigger steamers... Now I wanted Telex on my Br.23

 

Traction problem with Br.38 from the set 26549:

This is a very nice model but it has only traction tyres on the first powered axle that make's it hard for the locomotive to pull almost anything...

I ordered the first axle, spare part #130228, (including traction tyres) to exchange it with the last powered axle to get 4 wheels with traction tyres :

Picture #1 shows the axle 'A' (#130228) and the smoke generator (#72270) which I also mounted. I took of the body, picture #2, and the tender body also to find out that Märklin has installed another speaker than the one in the spare part list. The black wire that can be seen in picture #4 just above the middle powered axle needs to be unsoldered as this is the wire for the pickup shoe. I then turned the locomotive upside down and removed the pickup shoe and the red bottom plate as seen in picture #5. On the picture the new axle is already in place. Be careful with the middle axle so the springs under it doesn't fly away... Then put the red bottom plate and the pickup shoe back into place and resolder that black wire. Then put the body back on carefully, see the manual. Picture #6 show's the locomotive ready for some testing. It made a big difference !

On the pcb inside the locomotive the AUX-2 is not used. On photo #1 you can see that I have soldered a wire directly on the output on the pcb. Then I put the wire along the other wires and into the tender. Then I installed the Telex coupling, see photo #2, and soldered the wires. Then I did some function mapping on the decoder and put the AUX-2 to F 2. I used "moment function" on the F 2 so I don't need to push twice to turn off the Telex. That's it ! Now my Br.23 has Telex on the tender...

36240/36241 Br.24 Steam locomotive :

Here you see which solder pad goes where on the new Br. 24.

It's also valid for the model from the set 26564.