DCS signal strength on part of one channel only

The Engineered Filter is supposed to be "at the farthest point" from the TIU.

The TB is not the farthest point, The end of the track is.

I would move them to the dead end of the track.

Now, 2 tracks good, rest bad with the same setup is odd.

I suspect the bad ones are somehow shorting to something else or have a bad connection in the tracks.

Try ohm checking each one from end of wire to end of track, compare to the good track.

Do this with the wire loose from the Terminal block.

Good Luck !

Actually, the filters are supposed to be at the farthest point from the TIU AND on the TIU outputs directly.  Here's Susan's DCS Engineered Filter page.  Also, many have said that these are not really needed or effective on Rev. L hardware.

Here's the link to the design paper describing the theory: MTH DCS Filter Design Paper

To me the bulbs have always worked the best

Joe,

From what you describe, I am rather certain that the problem is not a DCS problem at all.

The engineered filters were invented for use on a buss type track topology and were designed to be used in pairs, i.e., one at the TIU channel output and one at "the farthest point from that TIU output".

You're using the filters on a track topology for which they were not intended. This very well could be the cause of your problem, since there is no "farthest point" on a blocked track plan.

Try just removing all of the filters. This may well resolve the issue, particularly if you have a REV. L TIU. However, if results are still not satisfactory, insert one 18 volt bulb across the black and red terminals of each TIU channel output or, if more convenient, across the entry to each terminal block.

On my mid-sized (but quite complex) layout, I use 9 REV. L TIU channels and have all 10's, without any filters or light bulbs at all.

Thanks Barry. I will give that a try tonite and let you know how it works out.

Joe K

Loose connection (track or terminal block)

I have isolated the problem to one block (one of the blocks that always had a 10 signal strength). this block, when connected, kills the signal strength in the other blocks. The block is only 6ft long, end ends at a lift bridge.

I have changed the wires to this block with no effect.

I am using fastrack. The center rail is isolated by removing the jumper wires at the connecting switches. The block has 2-10" sections, 1-30" section, 2 switches, 1-5" section and 1-5" length of atlas track leading to the bridge.

I removed the engineered filters, the signal on the 5 good tracks went down. Added the filters back in at TIU output and terminal block, and signal on 5 good sections back to 10's.

Replaced engineered filter with light bulb on TIU output channel, 5 good tracks still 10's.

Not sure what problem I can have in this short section of track.

I disconnect the switches from the straight track (which has the power connection) and there was no change (switches do not appear to be the problem)

I will try the following:

1) replacing all the track in this bad section, leaving the switches

2) get therapy if 1 above does not work.

Any other ideas?

Thanks: Joe K

After taking apart the one section of track that had the signal strength problem, I found a second hot lead, which was used to send track power to the AIU for powering my uncouplers. Once this lead was removed, the bad section no longer affected the signal strength in the other blocks.

I will have to rewire to get auxulary transformer power to power the AIU and its accessories.

Even though the AIU accessories were not activated (they are all attached to uncoupler magnet track sections), it interferred with the DCS signal strength.

I also found that a poor connection will reduce the signal strength, much more than you would expect, as a meter indicates there is still proper track voltage through the section.

Thanks for the help and ideas to isolate and eliminate the possible causes and getting this resolved.

Joe K