A Case Study in Improving TMCC/Legacy “Track” Signal
The TrainMasters of Babylon Model Rail Road Club of Long Island, NY was having trouble with poor TMCC/Legacy signal pickup. Their layout covers approximately 3000 square feet with multiple parallel tracks and some overhead crossings. Pat Nardella contacted me regarding their problems in February (2015). I suggested they buy one of my MANCO TMCC/Legacy Track Signal Measurement Devices http://www.trainfacts.com/trainfacts/?p=662 so that they could make quantitative measurements that would allow them to see if any changes really resulted in measurable improvements.
I asked Pat to get back to me with their results so that I could learn from their experiences and pass along any beneficial information to others. A few days ago I was very pleased to receive a 1 ½ page report from Pat detailing all the steps they went through and a summary of their results. He even included a couple of photos of their layout! I would like to share this report with you. I have [added] a few of my own comments into his report.
I do not know if you remember me. I called you on 2/5/15 about problems my train club, TMB Model Train Club, was having with Legacy. We talked a while & you gave me all sorts of advice. I also purchased the signal strength meter from you. You asked me to get back to you with our results. I thought I would put them down on paper rather than telling you them on the phone. This way you will have a written record of what I did & the corresponding results. But first let me thank you for your help; without a doubt, things have improved.
Okay, here is a quick review of where we started. The club has a 3,000 square foot layout with 4 different levels. We have 2 main lines, 2 branch lines which pass under the mainlines at different points, & a subway line which runs under the table. The outside mainline has 800’ of track, & the inside 700’ of track. The branch lines have 320; of track each, & the subway has 360’ of track. Most areas have 3 parallel tracks, some areas have 4 parallel tracks & other areas have 5 parallel tracks. (See picture 1 which is a photo merge of what our layout looked like last November.) When we started building thelayout we ran earth ground wires between all tracks. We also ran earth ground wires under all areas where tracks crossed above other tracks.
The first time we used Legacy no engine, neither steam or diesel, would run on our outside mainline without stopping continually. We had to hold our hand over the engine to get them to run.
So this is what I did before calling you.
1. Because, on the inside mainline, one steam engine ran fine. I ran more earth ground wires on both the outside & inside of the outside line. So now every track is sandwiched between earth grounds.
A. RESULT – all diesels ran well on the outside line & some steam engines, but most steam engines did not run. All tested engines, steam or diesel, run fine on the inside line. This is when I called you for help.
This is what I did after calling you.
1. Using your meter I tested the Legacy base. It is reading 2DCV without a load so I knew our base was working. Under load the reading was 1.38DCV. One of our problems is we bundled the earth ground wire with other wires common wires included. If you look at picture 2 you can see the green common wire is tied to the power cord wire.
(Picture wouldn’t print here)
In picture 3 this has been corrected.
(Again, no picture)
A. RESULT – the under load reading increased from the 1.38 starting point to 1.59.
2. Before I changed anything I used your meter to test 3 different areas on the layout. [The readings were made with the meter probes connected to the outside rail and a nearby earth-ground wire.] One location where we did not have any problems had a reading of .54 DCV. One problem area had a reading of .19DCV.
A. RESULT –After separating the common & earth ground the .19 reading went to .33.
3. Then I began to separate the earth ground wires from all other wires around the layout, plus I connected all earth grounds to one earth ground location. When I completed this task I took more readings.
A. RESULT – The readings at the base remained the same but the readings at the different locations around the layout were astonishing.
a. Location A went from .33 to 2.29.
b. Location B went from .19 to 2.51.
c. Location C went from .54 to 2.97.
At this point I thought we were ready to really test everything so on 3/20/15 we had a Legacy only test run night. We started out with various results. Some steam engines ran well, some were stopping at various locations. So I than connected the earth ground wire to pin 5 on the base.
A. RESULT – After cleaning some dirty track areas, all test engines, diesel & steam ran without problems!!! I know that dirty tracks can have a big effect on Legacy running.
We even ran a diesel on one of our branch lines & it ran without problems. Two weeks ago this would not have occurred.
So, at this time, I think we have solved most of our Legacy problems but I realize that we will have some problems with different engines. On behave of myself, & TMB train Club, I want to, again thank you for all your help & expertise. There is no way we could have gotten to this point without your help.
I understand that you sometimes attend the TCA York meet. I hope you see you there so I can introduce myself & thank you in person. Also, if for any reason you happen to be on Long Island, feel free to call me so I can bring you down to our club.
The very low readings at the 3 test points around the layout would make me very suspicious about the earth-ground wires to which the meter was connected. Later testing and reconnecting of the earth-ground wires to a central point that is tied directly to Pin 5 shows that some of the things that we think are good earth-ground points are inadequate. The best point is Pin 5, which is a direct connection to the earth-ground’s signal source inside the Base.
Pat’s steps show the utility of having a meter to quantitatively assess what happens when you make changes.
I would appreciate receiving other case histories like this one so that we can all learn what does and doesn’t work.