This morning I awoke early and went outside after I heard an unusual aircraft. Did not see it, but apparently a second wold war warplane and a RAAF chopper circled Albury Wodonga. Ths was the only sign that today was special.
THE RAILWAY
In the last few days I first tested the new wiring installed on the old helix.
I did this by disconnecting every DCC track section along the whole railway. I then found the positive and negative feeds for the old helix.
I needed to find a way to isolate and test, to prove that no shorts were present. And so I set up a new command station and plugged the helix into it.
The helix itself was wired up so that the top level was insulated from the rest.
The main power feed to the helix started from the BG station andthe SG from the crossover. This stopped at the top of the helix for BG and the loop points on the SG. It bypassed the reversing sections and continued through the newly installed wires along level 2 to 5 ending at the first points into Wanganella. A new feed will service the area behind.
The reversing section was fed from this same DCC circuit, however each pair of wires fed through a hex juicer rigged to operate as 3 isolated reversers.
Before all this could be completed I needed to hot glue the new feeders to the edge of the helix road bed. droppers were added by shaving the insulation and soldering them directly to the correct DCC bus wires glued along side the track.
Now the BG helix wiring works perfectly., apart from a minor imperfection at the insulated piece I cut in at the top of helix. An easy fix.. tests at DCC voltage 14.7 AC
However the SG helix tracks have failed, and it all appears to be caused by crossed wires in the next DCC section heading towards Allanvale. they test at DCC voltage 2.9AC.
As well the first BG train reached the top and passed over the insulators and powered through the section to Allanvale. Almost certainly the same crossed wire problem stopping the SG
My normal hodge podge of wiring which was mainly caused by adding and adding over time is very difficult to trouble shoot. Easy way out originally is still biting me
And so starting here, I worked back to towards the old helix removing wiring and sorting out the two DCC bus lines white and black were tied together and were SG feeds.
Grey and black tied together to represent the BG feeds.
When I was using a common black feed for SG and BG, I found it caused problems and so I added extra black feeds requiring separation. So far I have found many BG black feeds still connected to the old common feed (now SG feed)
I have also found BG reds connected to SG feeds etc etc.
The fix is to separate all wires that need it and move wires to correct DCC bus lines. Not finished yet, but hopefully this will get the system working properly.
The big gain is that as I finish the first renewed section (the old helix) I have also completely rewired the next Allanvale section. So slower than I would like, but moving right along.
A note on Albury reversing sections.
I seem to have proved my misunderstanding of reversing loops :)
Most times a reversing loop is formed by a single line dividing into a baloon loop at a pair of points (switch) allowing the train to travel around a loop and reenter the same single line.
And so if the left rail of the single line was a black connecion it would be the outside rail of the loop. This means when the track reached the points the black wire would connect to the right rail of the single lie, which is of course a red wire rail.
This would be a short and we can fix this by switching the loop from an arrival configuration to match the departure configuration. I use Tam valley juicers, or the switches on Tortoise machines.
In my case on this large layout, I have decided to just reverse a section of track long enough to carry my longest train. I believe my failure to make this work at Albury is that I have two separate DCC bus lines . One at Albury and other at Coal Sidings. I ran a separate section through the reverser.
At first I disconected that and fed the Albury bus into the reversers. This allowed trains to arrive and depart Albury. However they all shorted out at Coal Siding and had to be pushed over the gap.
I need to add one section to one side to mimic what I have done at the old helix. And so I am going to run the reversers here on the coal siding DCC bus by extending a short section of this bus into Albury. This will hopefully be the fix, I have been searching for all these months.
Ha Ha clear as mud, I expect
Cheers
Rod
