Legacy Signal Degrades w/ TIU Fixed

Dave,

When you swap the Legacy ground cable from TIU to TIU does the issue follow?

Have our layout split into two as well. The Lionel common wire is split and attached to our 4 common terminal strips, currently 2 for each TIU fixed out. We seem to have good Lionel signal, and with a double main the signal floats so far you could probably have the other track not even hooked in.

We have an issue either with the DCS signal on a section of tracks connected to one TIU output, or we have a finicky P3 engine, as the issue stays even if we swap outputs yet the Lionel signal remains strong.

Lima,

That is the only thing I haven't tried.  The other TIU is the one I have connected to a PC.  I will swap TIUs and see.  I will report the results.

Thanks for the reply!

Dave

Dave,

Is the Base 1L connected to the channel input of the TIU or its output? If the input side, that's quite possibly the problem.

Barry,

I have the base connected to the output side of the TIU.  

Thanks,

Dave

Dave,

Say 2 main lines, are they split:

half on 1 TIU output and half on the other TIU output?

half and half on the same TIU using both outputs?

one TIU output per loop, same TIU?

one TIU output per loop different TIUs and another TIU output is a yard, etc.?

IIRC correctly the commons are not connected to each other in these TIU's. We have an original as well and it has no fuses but commons connected? 

Have you tried it with the Lionel signal wire held onto those tracks by hand or tape just as a test? We've tested that way when it was easier than climbing under the tables.

Problem solved:

A special thanks to Marty Fitzhenry.

Marty gave me a call this afternoon and we discussed some options to try.  One option was to run some more ground plane wire under the affected area.  That was the easiest thing to try and it worked.  My TMCC engines did not seem to be affected only Legacy engines.  The area was also directly over the TIU.  I don't know if that had anything to do with it????

Thank you to everyone who replied!

Dave

Problem posted, diagnostic tree,eliminate the variables and finally resolve...gotta love this forum!

Dave, You might not have time for this, but the question would be if you used a different CAB-1L would the ground plane be needed?

I thought early on some CAB-1Ls had to be sent back for sensitivity or power out issues?  May have a CAB-1L with marginal output.  G

Dave,

When you mentioned it only occurred when the cable was hooked to that TIU, and the TMCC engines seemed to work OK, got the impression everything worked correctly prior to this. How did you run the Legacy engines before this? 

So far we've had two experiences with Legacy. First we were required to send our Z-Stuff Data Line Driver back to Dennis because Lionel lowered the Legacy base output which messed with it sending signal to the switches. Second was two Legacy steam engines that would constantly loose chuff over switches and never get it back so we returned them. IIRC someone on here then mentioned Lionel had changed the software to from the TMCC version where they automatically restarted chuffing to where they now required a battery to continue the chuff and that software was changed again back to the old way on the new Big Boys to eliminate the problem.

As mentioned above, it would be interesting to see if another base eliminates the need for the ground plane, especially as none was required before.

George,

I had a TMCC command base there before that was starting to act up in the same spot.  I didn't try unplugging the serial cable with that base.  I could swap it out and see.

I could reproduce the signal lost every time by plugging in the serial cable with the Cab1L. 

Lima,

I only had two Legacy engines that I mostly ran on the other side of the layout.  The whole thing still seems a bit odd to me.

Dave

David,

   Got to admit this is a strange one, MartyF cleaned up your problem for ya, I only have Legacy and no TMCC Cab1, my buddies Cab1 had a similar problem on my 2nd level, but we thought it was the Legacy Shay causing the problem.  There maybe more of a difference between TMCC & Legacy than we really are aware of.

PCRR/Dave