DCS/TMCC Signal Issues

#1 update your TIU and remote to the latest firmware. 6.10. It's not directly causing your issue, but again no reason not to update- it's needed for many advanced functions.

#2 Classic base TMCC RF signal. There are a LOT of things that could be factors- base slightly out of tune, power source not the right one or not grounded, needing additional ground  plane near layout.

Edit- update- yes, your new engine might have a sound card issue and it might not be signal related- the question would be do you have other TMCC or Legacy engines, and they all work fine and just this since one has the issue?

@Tony posted:

I'm running a TMCC base (not Legacy). I have the appropriate pin cable connection, and running the "one wire" common from the command base to the fixed output common ground which feeds the track.

I'm not trying to nit pick, but an important wording and concept here is that your track outer rail is not "ground".  All of our typical model train transformers are full isolation transformers and as such, your track is not tied to earth ground. Specifically the TMCC or Legacy base uses an extremely specific power adapter that internally is wired such that the output is grounded powering the electronics of the base. In other words, your track is floating- not earth grounded, and connected to the transmit post of the base. The base in turn uses earth ground via the special power adapter with a 3rd ground pin to the outlet.

Again, in TMCC, your track is not grounded. It's better in the forum and discussions to use the word "common"- when meaning this outside rail and often U terminal of many transformers. Common just means they are all connected together- but not earth grounded.

Vernon,

Thanks for the response. I plan on the update as soon as I have access to a computer.

I'm confident the power source is correct and grounded. We can rule that out.

I've added additional grounds along the layout. It did not remedy the issue.

I am not aware of a method for "tuning" the command base. Can you educate me on this topic?

Thanks,

Tony

Thanks for the guidance on terminology. I like to be precise on that stuff.

@Tony posted:

I am not aware of a method for "tuning" the command base. Can you educate me on this topic?

At this point, I am not sure you have this issue and may not be a path we need to go down. The title of the topic is "DCS/TMCC Signal Issues" hence why at first I mentioned this as being a possible reason for a TMCC signal issue. The tuning is the fact these are 1990s electronics that age over time and can slightly change radio frequency over time and thus be out of tune with the frequency the engines are listening for.

Again, if you have other TMCC or Legacy engines and they all work all over the layout and this is the only one having an issue, I would not then go down this path thinking the base is "out of tune".

Again do not do this unless you have a problem, you could easily tune your base right out of working status.

https://ogrforum.com/...tuning-knob-location

This is from the late Dale Manquen, he studied the TMCC system inside and out and was a great resource.  I've used this technique a few times.

Start by warming up the base at least 20 minutes or so and then you can check the tuning.  Nowadays, I slap a 'scope on it to verify the tuning, so most of the time I don't have to tune.

Gunrunnerjohn,

Was hoping you'd relpy, as it was your previous posts - and warnings about using the appropriate tools - that have me questioning the PLCC chip issue. I'm pulling the shell tonight, and my puller should arrive tomorrow.

Any other thoughts on this?  I only have this one Lionel/Legacy - all my other engines are MTH, so I have no others to test and compare.

Good News Update!

Vernon Barry and Gunrunnerjohn,

Based on some of John's previous posts about loose connections, I removed the shell today and began a detailed inspection.  I located the PLCC chip but did not attempt to touch it until I get the appropriate tool.  Nevertheless...

I was shocked to discover just how loose these two parts were.  Both were working their way off the connecting pins.  I'm hoping I can upload the pic for you. The pic is after I re-seated these parts.

I reseated both and started the engine up.  I ran it around the loop for about 15 minutes, and just about every circle around the loop I blasted the horn.  It rang out clear and loud every time.  No hesitations, no static.  Just a clear loud horn. 

I'm not celebrating yet. I'll run it a bit tonight and tomorrow to be sure before I put the shell back on.  But I am cautiously optimistic I may have found the issue.

Thanks for your advice.  I'll be asking for more!

Tony