Atlas 220 wiring

[DuceNova]

HELP! 

I'm just getting back to a HO train setup that hasn't been touched in YEARS.  It will eventually be modeled around the Erie Lackawanna in the diesel era (with possibly some steam).

I bought a MRC Prodigy Advance2 system and have slowly but surely made progress with all wiring. 

I'm now at the point where the blocks make sense EXCEPT the reverse loop Atlas 220 wiring!  I can get it set so that a locomotive will enter it from the loop on one end but can't reverse it without getting a "short" indication on the DCC.

My best guess is that I need to take this unit out and install a DCC reverse controller?

Any and all help will be greatly appreciated.

[rich1998]

I do not use reversers but there are a couple Yahoo DCC groups that might also be helpful.

Wiring for DCC with a lot of info in the Files and Photos sections, plus the group is quite active.

http://groups.yahoo.com/group/WiringForDCC/

MRC DCC specfic.

http://groups.yahoo.com/group/MRC-DCC/

I know some here might have suggestions but I find more DCC groups have been a big help for me when they address a specific area. There are a lot of areas for DCC.

lex

[DuceNova]

One of my many "quests" this winter was to clean the cellar which is where the HO setup resides.

JUST after posting my question here I decided to go through a pile of boxes that I knew held HO stuff.  Wouldn't you know that the FIRST box I opened was full of Atlas parts:  #4 turnouts, solenoids for turnouts, switches for turnouts, AND (wait for it!) a NEW IN THE PACKAGE #220 Controller!

On the back of that package was a complete description of how it works!  Top left and bottom right red slide switches control the A or B track direction only (NOT the reverse loop).  The middle left green switch is A off B cab selector for the reverse loop.  The top right gray switch controls the reverse loop direction.

I had an "AHA" moment the minute I finished reading all of that as it all came back to me what I wired 20 years ago. 

The question was then how do I know what the polarity of the reverse loop is in relation the main track.  Another "AHA" and "KISS" moment:  hooked a HO scale incandescent lamp from one rail of the reverse loop to the main line rail of the same side at each end of the reverse loop.  When the polarity for the end of the loop is the same as the main line, the lamp is out.  When it doesn't match the lamp is lit!  Voila, a visual indication that the polarity is either right or WRONG!

[Joe Satnik]

If you really wanted to get fancy, I suppose you could paint that bulb red,

then wire a green bulb from one rail of the main, (across the double gap) to the opposite rail of the loop.   

[jward]

this is the sort of resourcefulness that makes this a great hobby.....

[DuceNova]

Yes, red and green lights are on the "To Do List".