Progress continues but as this layout has reached the detailing stage, less appears to happen and it takes longer.
In the case of signals this is due to several factors
- Signals are expensive so are slow to acquire if I'm to stick to the monthly budget.
- Which decoder - these aren't cheap either.
- How to connect the signals to the decoder.
The easy answer for DB HO modellers is to go for Viessmann for the simple reason that they have a multiplex drive arrangement which means four wires maximum to connect the signal for the decoder and you get the wiring harness ready made. The cost is not that bad either but I didn't go down that road because I have a Z21 system and I use the Z21 app on my phone to control it. One of the features of the Z21 app is that for the right kind of signal decoder, you can display facsimile replicas of the signal you are controlling. ie what you see on the controller app is what the signal looks like on the layout.
Now the 'right' kind of signal decoder means the Roco Z21 signal decoder. The outputs are intended to control individual signal lamps, not Viessmann multiplexed signals. As I really liked the idea of 'proper' displays on the app, I chose the Z21.
The next step was to choose signals to go with it. The convention for all the signals I looked at is common positive which matches the Z21 signal decoder. MSL have recently started selling a range of DB signals by Spanish company Mafen. They look rather good and they are incredibly thin front to back just like the real thing. This is an entry signal:
It has four wires which are terminated by resistors for the LEDs and I assume a diode for the positive. The base is by Viessmann!
This is a departure signal with distant signal, with marker light to show that the stop signal referred to by the distant is closer than the standard distance which I think is 1km on normal lines.
This signal has 12 wires! I have not yet dared to mount it on the Viessmann base because there's some filing to get a good fit and then all 12 wires + resistors have to be fed through the hole.
Deciding how to connect the signals to the decoder was a challenge. The leads out of the signal are about five inches long and have to go through the baseboard. The decoder is not going to be close enough which means creating an extension harness. The wires will have to go through the baseboard unconnected and then need to be reasonably easy to connect once there.
The solution I have adopted is to create a connector mounted on 0.1 inch strip board. The signal wires go into PCB mounted screw terminals and the cable from the decoder goes into 0.1 inch pitch dual row header / crimps. I was able to use parts left over from my LED lighting project from a few years back.
Here's the completed connector.
The next step is get the decoder mounted under the baseboard and the signals on top....
David