Skip to main content

That's an interesting point Rick. When I was just running TMCC, everything seemed fine, and all six supplies were plugged in. This Legacy testing exposed the wiring problem when I tried to selectively disable sections of the layout. At least two supplies are bridged, one north and one south. I'll do my "witch hunt" later. I'll look over my master list and try to narrow down the search. I don't think it will be too hard to find.

Yes Matt, but there may be a complexity factor or something environmental that you can't replicate on your layout. As I said before, I have engines that work fine when tested elsewhere, that don't work on my layout. You should know that better than anyone.

The fact that you had it working, leads me to believe that it could be where I have it mounted. Something is killing the signal.

Dale Manquen posted:

full 1 volt sine wave  ???

I see 6.3V peak-to-peak for my Legacy Base with no load on the Track output.

Yes, my base(s) have about 6 volts pp as well. Is it possible that on some layouts, at reduced output will function flawlessly and not work well on perhaps more extensive layouts. Or not on layouts with quite different environments? I have seen bases with low output around just less than 1 volt pp that were probablimatic and needed to be sent in for repair.

Disclaimer: Not an EE, in no way am I nearly as qualified as the folks who have already responded.

My $0.02 is: My dad (Nuclear Physicist) always told me that whenever something is "screwy" with your electrical circuit (trailer lights for the boat, Legacy signals ?), look for some kind of ground/common fault. I have always found this to be true.

So I mean no disrespect when I ask: Is "common" common throughout (For instance, is the TMCC "common" the same as the Legacy "common" for power, etc.)? I have had a lot of wiring issues with common (much smaller layout [who's isn't!] but three loop layout) and still had switches work, etc. It just seemed that there was always "a place that things didn't work well" which, ultimately, I traced to not have common wires "common" (i.e. "ground").

Just trying to help...

Bruce

Thank you Bruce.

Regarding the "common" none taken. The connection wire that I used is the same one that has been on my TMCC base for years. I just moved it over to the Legacy base, per Lionel's instructions. It goes out to the network of ground buses and track feeders.

If there's one thing I do have, it's feeders! Every 3' section of GarGraves track has a ground, a hot, and on the mainline only a detection wire. Non-mainline track has both outside rails tied to ground (no detection). The hots and grounds are tied to 12 gauge buses, and go back to the two power panels. There are two 12 gauge ground wires that just tie the two panels together and keep all six supplies on exactly the same ground.

I don't know if it is possible to have too many feeders. If it is, I might.

If TMCC base works fine. And the Legacy base appears to work fine on another layout. Bruce's comment on a ground fault is worth looking at.

Try using your Legacy set plugged into your normal layout power point. Then just try a short length of track seperate from the layout with a power supply  and one engine and see if it works correctly. If not try on another power outlet.

I recently had a issue with LCS which appears to have been due to a fault within my Legacy base. This sort of thing can be tricky to diagnose. I also had a ground fault from a Hellgate Bridge.

Maybe Lionel need to look adding a diagnostic aspect to the LSU software. So you could plug in a serial/USB cable into your PC and the software would test all the outputs were correct and everything is operating correctly. 

Nick

 

Elliot,

Referring to the comments concerning grounding, and having/not having, too many feeders.  I worked in club/large concert PA and Sound productions for years in the 70s.  One problem we came across at times was a "ground loop".  With this, as it sounds, a completed loop of grounding, there is a tendency for picking up of RFI.. Radio Frequency Interference.  In the business of sound reinforcement it caused severe feedback and the introduction of stray radio signals from Citizens bands, short wave, intercom systems, etc. over the stages PA systems.  Perhaps such a type of ground loop is produced within your layout wiring, and it is interfering with the signals to/from the Legacy base.

Any thoughts or comments?

Jesse

MOKATX and Harty Beatris RR

 

 

 

texastrain posted:

Elliot,

Referring to the comments concerning grounding, and having/not having, too many feeders.  I worked in club/large concert PA and Sound productions for years in the 70s.  One problem we came across at times was a "ground loop".  With this, as it sounds, a completed loop of grounding, there is a tendency for picking up of RFI.. Radio Frequency Interference.  In the business of sound reinforcement it caused severe feedback and the introduction of stray radio signals from Citizens bands, short wave, intercom systems, etc. over the stages PA systems.  Perhaps such a type of ground loop is produced within your layout wiring, and it is interfering with the signals to/from the Legacy base.

Any thoughts or comments?

Jesse

MOKATX and Harty Beatris RR

 

 

 

A few years ago, there was some talk about wifi interfering with the Legacy base signal and changing channel #'s might help.

OK .the Legacy works  at a friends layout.   You guys in the same town or hydro area?

 If both the legacy base & TMCC base are joined by a Y connection only one "U" connection    to the track    cab be used.          

In the pics   it looks like the " U on the legacy base is connected,,, Why not trying disconnecting it and try the command base  U connection.   fail?

Gregg posted:

OK .the Legacy works  at a friends layout.   You guys in the same town or hydro area?

 If both the legacy base & TMCC base are joined by a Y connection only one "U" connection    to the track    cab be used.          

In the pics   it looks like the " U on the legacy base is connected,,, Why not trying disconnecting it and try the command base  U connection.   fail?

Doesn't work that way. You need to use the Legacy base as the track signal. Legacy base does not communicate with the Cab 1 base. The Cab 1 base sends commands to the Legacy base. 

I HAVE FOUND THE ELECTRICAL BRIDGE. After mulling over my power district list, I concluded there was only one place to look. Districts for the north and south supplies touch there. There's a switch at the top of the big helix. This one happened to be a Ross Ready with all the center rail segments bridged together. Usually I cut those off for mainline switches, but obviously I missed this one. I'll get the Dremel and cut the two pins on the frog end, because I can't get under it to clip the bridge. That will separate the three districts and the two supplies. MYSTERY SOLVED!

There could be a lot of ground feedback loops, especially on the main level, where I'm having TMCC problems. When I wired the upper level, I just ran a single ground wire all the way around. I have good signal up there. My only concern is potentially over loading the 12 gauge wire by having it serve too many districts.

ampacity chart that I use rates 12awg stranded at 9.3 amps per 1000 feet for power transmission

This statement is incomplete.  You must tell us the nominal voltage and the percent of allowable drop.  Wire size vs. voltage drop tables are typically for 2% drop of some nominal voltage, and they are usually for a complete out-and-back pair of conductors.  For your example, for a 1000 foot loop your voltage would need to be 1500V to have a 2% drop.

Maybe the easiest way to deal with this whole ground business is to use one 12 gauge wire for all the districts on one supply. This will divide the layout into six reasonable zones. Since each supply can only deliver 20 A anyway, the wire would be appropriately sized. If you break it down in terms of trains, at 2 A load per engine (I use almost all can motors) that works out to up to ten engines per supply. I don't use multiple engines on a train, so we could be talking up to 60 trains layout wide. Trust me, that will never happen! Maybe 20 at the absolute max moving at any one time.

I'm afraid I don't have anything to offer that has not already been suggested by others at this point.

You have a fantastic layout, Elliot, and I do hope you can get the legacy base sorted out.  Others that have already chimed in would know a lot better than I, but my only thought is that there is some sort of load on the legacy signal grounding it out somewhere.  For those that know more than I do, does the Legacy base and TMCC base use the same output circuit, or is it possible that the TMCC signal is more powerful and can overcome a medium resistance connection to earth ground?

By the way, I love the idea of using the 6v transformers in series.  

JGL

Last edited by JohnGaltLine
Dale Manquen posted:

ampacity chart that I use rates 12awg stranded at 9.3 amps per 1000 feet for power transmission

This statement is incomplete.  You must tell us the nominal voltage and the percent of allowable drop.  Wire size vs. voltage drop tables are typically for 2% drop of some nominal voltage, and they are usually for a complete out-and-back pair of conductors.  For your example, for a 1000 foot loop your voltage would need to be 1500V to have a 2% drop.

Dale, I realize that now. I grabbed the chart from a manufacturer's site some time ago. I assume that this is referencing the load carrying ability before wire or insulation failure. I was originally concerned with trying to find some safety points of reference.

It seems to me that the distances needed to have a noticeable voltage drop for 12 AWG aren't found on most home layouts. It could be possible on Elliot's layout, but he has created multiple power divisions. I would not expect a voltage drop on his layout.

I was responding to his recent comment of concern  if the 12 AWG would be large enough.

I just tested my Legacy command base, curiously the voltage output was actually greater connected to the tracks than open circuit.  5.64VPP open circuit and 6.20VPP connected to the track.  There is only about 100 feet of track connected, not quite like the layout in question, but that seems to suggest what you should see as an output signal.  The ground for the 'scope was connected to the same power strip ground connection as the command base power brick.

Command base not connected to track, 5.64 VPP

ADS00001

Command base connected to track, 6.22 VPP

ADS00002

 

Attachments

Images (2)
  • ADS00001
  • ADS00002
Last edited by gunrunnerjohn

The TMCC Base had just a series coupling capacitor feeding the output, but the Legacy Base has additional inductor and capacitor components at that point.  I don't know if they are to help things going out or to filter things from coming back in.  Might be cutting down the digital trash from the internal clocked circuits, or not.  Anyway, they do seem to interact with the load's reactance.

Gregg posted:

 How    are things now?  Does legacy work anywhere? or same old ?

 

My helper Joe was over yesterday, so we worked on other things. Nothing has changed, except I located the electrical bridge as I mentioned in a previous post.

When I go downstairs later, I think I'm going to back to straight TMCC, while I try to simplify my ground wiring.

I ordered Dale's signal strength meter, which should be here Monday.  At this point, I would love to perfect the TMCC signal, then I can revisit the Legacy base after that. I'm afraid that thing is going back on the shelf for a while.

That said, please feel free to continue this discussion, I'll be listening, and others may find useful ideas here.

THANKS GUYS!!! THIS IS WHAT MAKES THIS FORUM SO GREAT.

Last edited by Big_Boy_4005
Big_Boy_4005 posted:
Gregg posted:

 How    are things now?  Does legacy work anywhere? or same old ?

 

My helper Joe was over yesterday, so we worked on other things. Nothing has changed, except I located the electrical bridge as I mentioned in a previous post.

When I go downstairs later, I think I'm going to back to straight TMCC, while I try to simplify my ground wiring.

I ordered Dale's signal strength meter, which should be here Monday.  At this point, I would love to perfect the TMCC signal, then I can revisit the Legacy base after that. I'm afraid that thing is going back on the shelf for a while.

That said, please feel free to continue this discussion, I'll be listening, and others may find useful ideas here.

THANKS GUYS!!! THIS IS WHAT MAKES THIS FORUM SO GREAT.

I may have missed it, have you tried another Legacy base?

John, Matt tried my base on his layout and said it worked, and I believe him. I consider that loop test done and the unit passed. That being the case, the problem must be with my layout wiring, or the environment in the train room. The only other possibility that makes any sense would be a weak output level from the base.


 

One thing that I may not have mentioned in this conversation, though I have said it before elsewhere, to me Legacy is just the frosting on the cake. The cake is still TMCC. I only bought Legacy to access the extra features on my Milwaukee Road S-3. For the purposes of normal operations, TMCC does everything I need, speed, direction, couplers, and turning the volume down or off.

This does not mean that I don't want to get to the bottom of this. It just means that it isn't a high priority, as was demonstrated by my setting it aside for almost four years after my first attempt to set it up when I bought it.

Add Reply

Post

OGR Publishing, Inc., 1310 Eastside Centre Ct, Suite 6, Mountain Home, AR 72653
800-980-OGRR (6477)
www.ogaugerr.com

×
×
×
×
Link copied to your clipboard.
×
×