Lionel SC-2 and TMCC signal issues

Are you using anything to conduct the plane? I'm new to this stuff but if I follow what you're saying, it sounds like your ground plane needs some work. Maybe some chicken wire stapled under your layout?

@BillYo414 posted:

Maybe some chicken wire stapled under your layout?

You want to be somewhat circumspect in how you address this issue, you can make a bad situation worse with the wrong configuration of earth ground or too much coupling between earth ground and the tracks.  One of the major contributors to weak TMCC/Legacy signals is too much capacitance between the earth ground and the track.  This really comes up with really large layouts with thousands of feet of track, places like the NJ-HR layout deal with that issue.

@BillYo414 posted:

Are you using anything to conduct the plane? I'm new to this stuff but if I follow what you're saying, it sounds like your ground plane needs some work. Maybe some chicken wire stapled under your layout?

What I have been using so far for tracks is I take metal tape that's used for heating and sheet metal work, and I tape it below all the raised tracks. I connect all this metal tape together mostly by taping on top of tape, but some places have wires.  This doesn't work by itself, but what fixes the situation for trains is grounding that metal tape to the 3rd prong of the wall outlet. I have an actual degree in EE, but I have zero idea what's going on here myself really.

Honest, I thought I figured this out, and tried a similar thing under the track, of putting metal tape under the layout, and then putting the SC-2 below that with various combinations of wires from the U pin connected to the SC-2 or with wires beneath it, and nothing helps.

I do see posts here in this forum where people declare that it's not a ground plane, and that something else is going on, but mostly they're talking down the official Lionel explanation and I have yet to see someone really say what's going on here.

I wish I could just modify this SC-2 to be honest, and wire it in directly and rip out the antenna, but not sure if that's possible.  I have a PowerMaster that's connected right by it that basic works perfectly no problem.  The whole TMCC signal thing is pretty confusing, especially coming into a layout that's already built.

Try moving the SC2 to a new location.

I loosely wrapped one turn of a ground wire around my SC2, and it went to 100% reliability.

The ground wire is connected to pin 5 of the command base.

@Cathryn Mataga posted:

What I have been using so far for tracks is I take metal tape that's used for heating and sheet metal work, and I tape it below all the raised tracks. I connect all this metal tape together mostly by taping on top of tape, but some places have wires.  This doesn't work by itself, but what fixes the situation for trains is grounding that metal tape to the 3rd prong of the wall outlet. I have an actual degree in EE, but I have zero idea what's going on here myself really.

Here's an excellent treatment by the late Dale Manquen, one of the best coverages of the TMCC signal basics I've seen, and better than I would explain it.  It will also save me a ton of typing.

TMCC Signal Basics by Dale Manquen.pdf

Cathryn:

found this on another SC-2 post. don't know if it has anything to do with your issue but thought I would paste it here.

The SC-2 needs to receive a signal from the house wiring ground. An easy test is  to temporarily lay a three wire extension cord next to the SC-2. The extension cord must be plug  ged into a three prong outlet. The Cab-1 does not talk directly to the. SC-2. Placing your hand next to the SC-2 will let see a stronger signal also. If this experiment improves operation, a permanent solution would be to install a ground wire near the SC-2.

I have a similar size layout, also a wire rats nest, no problem with (3) sc-2's. here's my wiring environment:

-powering them with their wall warts connected to a power strip with heavy duty extension coiled on the floor approx 4' from the SC-2's.

- to power the switches, a Powerhouse connected to a ZW-C (in your environment would be the Powerhouse connected to the Powermaster)  is connected to the same power strip with heavy duty extension cord coiled on the floor.

- my track is powered by (4) PowerHouses, (4) PowerMasters and (1) Command Base. The Command Base along with each of the PowerMaster Common (U)  terminals are connected to the common (U) of the ZW-C (in your case Powermaster) is connected to the common (U) of each of the Powermasters.  These ( Powerhouses , PowerMasters and Command base are connected to another  power strip with heavy duty cord plugged into the same duplex wall outlet along with the power strip supplying the SC-2 and switch power.

Cathryn, your environment is similar to mine so it should work. after checking all the physical connections  of the SC2-2's to the switch motors, that you have a common (u) for everything tied together, Cab1/2 antenna extended,  a different wall outlet? sorry for the scatterbrain approach. I have been there many times myself, but ultimately find the solution, slapping my forehead in disbelief.

All the best!

-

I have three SC2's controlling my turntable, no power anywhere near them, and they do fine.  The most you should have to do is to run the outlet ground close to them.

As a follow up. I don't know what's going on with me, Base-1 and SC-2. I never got it working reliably, it was just always in a weird random state where it'd switch some switches one way, but not the other way.  I'm not sure why we have two Base-1s, but both do the same thing.

But, what I did, is I picked up an ASC3000 on Ebay, for not much money, and this worked brilliantly and perfectly the first time.

What is the wiring like in your home? Is it older where some electrical outlets are only two pronged?

The trains are in an addition to the garage.  There's no dry-wall here, and all the electrical wires are in conduit.  Everything here is 3-pronged, so it's not super ancient, but maybe the conduit is the problem? I can mostly control trains okay with TMCC, there are few spots where I see some blinking lights, but I just never stop there.

With TMCC, the house wiring is how the signal is transmitted. I could see metal conduit being a problem there.

unless it’s also grounded. Which it should be, I think.

I could try bonding the conduit to ground, though I have zero idea if that's code or not. It's  working now with the ASC3000, I think maybe I'll stick with that for now, not mess with the wiring.  I like how this is just direct wired to the serial port.  With the SC-2 I did made an honest attempt at putting the O-wire or the GND wire near the box, and I never got it reliable.

Asc 3000 has the TMCC signal wired directly.   The SC-2 has a signal system similar to a diesel unit or locomotive, where the signal is picked off the track out side rails.  You may have to position the SC-2 closer to a track that has good signal.

The cure for the SC2 is to run an earth ground wire close to the box, that usually fixes stuff like this.  Also, the common of the SC2 power supply MUST be the same as the outside rail so that the TMCC signal comes through.  I use a bunch of SC2 boxes on my layout, no problem at all with the proper wiring.

Thanks, I get it, this shouldn't be that hard, and I've been through this with other hobbies, where it seems impossible, but I'm just doing stupid thing that's obvious to more experienced people.  I still have the SC-2 and I do have some accessories and lights and things, that maybe I could hook to it if I can figure it out.

I did cut the jumper, and I have tried powering this with both the accessory transformer and wall wart, both, and got the same results. I did try various schemes of hooking a wire from the outlet ground, also from the Pin 5 on the RS232 and lying it near the SC-2 based on previous suggestions here.

"Also, the common of the SC2 power supply MUST be the same as the outside rail so that the TMCC signal comes through."

This could be it here It's possible I don't have common on my accessory connected to the  rail common.  I took a few month break from mucking with this thing, but I have some time to try again coming up here, now that the train-room is a little bit more comfortable temperature-wise.

@Cathryn Mataga posted:

"Also, the common of the SC2 power supply MUST be the same as the outside rail so that the TMCC signal comes through."

This could be it here It's possible I don't have common on my accessory connected to the  rail common.  I took a few month break from mucking with this thing, but I have some time to try again coming up here, now that the train-room is a little bit more comfortable temperature-wise.

That would be a major issue, the SC2 needs to get the other side of the TMCC signal via that power supply common.  That is most likely your issue.