Sunday, September 18, 2011

1....Tick 2.... Tick 3.... ???

I didn't get into the shed on Saturday this week until after lunchtime, and time was short as we had to go to a 3 year old's Birthday Party at 3:00pm.  When I got there I found the DCC system left on from last weekend.  Oops!  The first job was to look at the Cassino to Fairy Hill Loop staff machine circuit.  I tested the power supply for this staff machine and it was putting out 12V.  I tested another power supply circuit where the LED's were working and it was putting out 2V.  I thought I would make a new one up and connected it up and it too was producing 12V.  Hmmm!  I decided to put an LED across this power supply and the bi-colour LED lit.  I turned the bi-colour LED around and it lit the other colour.  Double Hmmm!  So I now decided to start at one end of the section and individually check each panel's wiring.  There were eight panels.  On the third I discovered a loose wire.  I attached it and then applied power to the layout and luckily these panels now all successfully lit.  So an open circuit was producing the 12V reading.  When under load, it produces 2V.  Job 1 Complete. Tick.

After returning from the first birthday party of the day, we had a few minutes while the kids had a shower before we went off to the wife's oldest sister's Surprise 50th Birthday Party.  So I glued down the track across the Upper Richmond River Bridge just north of Kyogle and let it set overnight.  I did this while I was supposed to be getting ice out of fridge in the shed, for the esky so we could take all the yummy sweets the missus had made for the party.  Job 2 Complete. Tick.

Sunday just before midday Brendan came over to hopefully rescue me from my incompetence.  He also came armed with 2 x 38's and 6 x FS, BS and BSR coaches for a test run.  After chewing his ear off for a while about layout stuff, we set about to attack Job number 3.  Measuring, Testing, Thinking, Thinking, Testing, Measuring, Testing and more Thinking.  We discussed a suggestion that another electronics mate from the Gosford Club who visited our Club Exhibition a few weeks back had made and this was discounted due to some sound logic from Brendan.  This suggestion was to install the resistor before the push-to-make button on the microphone circuit instead of after it.

After not much progress at debugging me predicament, Brendan started at one end of my plug-in-point panels and checked them out.  They all looked good.  However, my panels were wired in two radiating runs.  When Brendan attached him Ohmmeter to the circuit, when we plugged into the panels and pushed the push-to-talk button on one run as opposed to the other run, we got different results.  But with what looked like the same wiring on both runs, and different result, we were scratching our collective heads.  Brendan decided to check my tag strip where I joined my two run together.  You guessed it!  He had hit the nail, or in this case the loose wire on the head.  One of my wires had come loose on one of the runs and was shorting the microphone circuit.  Brendan soldered that up and and we gave it another test.


Later on we did another test with the DCC system on and there was a slight hum in the background.  We will keep an eye on that as I add additional plug-in-points.  I now have a task for next weekend.  Wire up the next 18 or so plug in points and test every one as we go.  Job 3 COMPLETE!!!!!  Yeah! A great big Tick.

So with the jobs finished for the weekend we set about having a bit of a run with Brendan's 38's and coaches and my CPH and a couple of 44's.  I stowed the CPH and its trailer in a siding at Kyogle.  I then ran one of the 38's past it and as it did, a strange thing happened.  The CPH tooted its horn!  I ran back the other way and the CPH said "MAX. MAX".  I ran back again and it tooted again.  Back again and it repeated its words.  Now that was strange.  Later on we ended up with two 38's hauling the coaches past the CPH and when it did, Brendan recorded the event on his phone.  I expect him to put this footage up on YouTube possibly tonight and you can see it yourself.  One 38 made the CPH toot while the other made it talk.  They did the opposite in the other direction.  We assume that it had something to do with the magnetic fields generated by the 38's motors on the reed switch ciruit on the CPH.

Tuesday night this week is at Mike's place so it will be good relaxation event.  And the next runnign session is now getting closer.


  1. Sounds like you had a very busy but VERY productive weekend all round. As for the running session, my October Saturdays except for the last Saturday of the month are already booked out. Busy month! GB.

  2. Here is the video. Will post it on my blog soon.

  3. The CPH and 38 class fault is called 'Crosstalk', although I have only ever heard this fault in 1:1 scale. The fault occurs in two ECP (Electronic braked) trains which both have earth faults and the faults 'crosstalk' to each other and can do funny things to the train brakes.