For some time I have been having some severe signal problems with my DCS system. Have an extensive fleet of  MTH engines on the main layout; engine not found, engine or repeat sounds when a soft key pushed or unresponsive buttons and difficulty operating lash ups. I had gone through the DCS guide rewired it with star pattern added lights to the distribution power block etc. as recommended in the book. I have been moving TMCC engines off the main layout . Last night I moved my 2 remaining TMCC engines to a siding turned off the power to that siding and unplugged the TMCC power supply. Instantly everything DCS worked perfect. No more signal problems. I went looking for a 22uh RF choke for the TMCC engines that was recommended in the DCS guide. It was suggested a 4 amp choke but the electrical shop did not have any that big will keep looking. Happy to be running trains trouble free again now. 

Original Post

I'd try plugging the base back in and see if DCS still works ok. Keep the TMCC locomotives off any powered track just to isolate the issue. 

I've noticed no issue from the TMCC base on my layout interfering with DCS but some TMCC locomotives will. I've mostly had an issue when 3 TMCC locomotives are powered and more than one PS2 locomotive is powered up. Then I'll have DCS signal loss issues in some spots. Park one of the TMCC locomotives on an unpowered siding and everything is fine again.

Santa Fe, All the Way

Ebay is your friend for cheap electrical parts or Newark, Mouser, and Digi Key.  I've had to ad the choke to a few engines.  When ever I upgrade a engine I always add the choke.

I spent some time testing today to see where my DCS signal is going bad with TMCC. Had a DCS lashup of 3 engines running on the main track and 2 other DCS engines running, I did the track signal test on these 2 engines at the same time. An Older PS2 engine with on 2 middle rail roller pickups showed 10's around most of the mainline with the odd 7 or 8 through a 3 Gargraves switches several other Gargrave and Atlas Switches it stayed at 10 and around most of the layout. A PS3 engine with 4 pickup rollers on the middle rails showed 10 the entire loop of the long mainline. When I plugged in the TMCC Trainmaster base the signal on both trains dropped to low #'s like 2 -4 or 1 or both engines read out of range. As soon as I unplugged the TMCC base the signal quickly rose back to 10's. I tired 5 different TMCC equipped engines a Weaver Steam, Sunset Third rail F9 A and B, K-Line F59 and Sunset Third Rail RDC. With the TMCC base unplugged and track power turned on to any track these engines were sitting on they started up with no TMCC on the track but did not affect the DCS signal. The Signal only went to out of range on the DCS remotes when I plugged in the TMCC base. 

??? Any suggestions on what my problem is? The DCS system runs near perfect with no TMCC plugged in??? And the TMCC equipped engines do not seem to be a problem when the base is not plugged in?   

Remove all TMCC/Legacy locomotives from your layout. Unplug the TMCC base. Run DCS locomotives. Plug the TMCC base in. See if there is any signal problem. If not add TMCC locomotives back one at a time (i.e. only one TMCC locomotive on the layout powered up at a time). See which locomotive causes DCS signal issues. Install choke on that locomotive. Problem solved. 

Santa Fe, All the Way

This is VERY odd! When you plugged the TMCC base back into the layout, did you have any TMCC or Legacy engines on the tracks? If so remove them and repeat the test. It is highly unlikely and improbable for the TMCC base unit alone to affect DCS. It has been demonstrated literally 1000s of times that TMCC and DCS are separate but compatible systems. That said, when problems do arise with the DCS signal, the chances of the TMCC engine being the culprit are extremely high. There are multiple, well known, documented instances with certain brand and model TMCC equipped engines not playing fairly with DCS. Bad TMCC bases, while possible, are extremely unlikely.

As others have stated, verify that DCS and the TMCC base are indeed working correctly together. If you cannot do that, no need to start dealing with the TMCC engines. You will get nowhere. Instead, try another TMCC base just to cover the possibility. You can also break things down to the simplest set up and connect  DCS to about 3-6ft of track. (Put the track on the floor so an unplanned run-away does not launch an engine!) Check your DCS signal strength.  Then connect the TMCC base (without a TMCC engine) and recheck the DCS signal strength. If all is okay, add a TMCC engine to the mix. If all is well, swap TMCC engines and keep testing until you identify all the bad actors. Bear in mind there may be more than one!

 

Chris

LVHR

It has actually been demonstrated that in certain situations that the TMCC signal can interfere with DCS.  It's surprising that it's as bad as he states, but it is possible.  Adrian has posted several threads on the issue, and he's currently working on a solution, although it won't apply to using the WiFi connections, only for folks using the 900mhz DCS remote.

lehighline posted:

That's why I almost never say "never". As soon as I do, someone will find the exception!

I'm your man, that's what I'm here for.

I did some more testing today. With no TMCC engines on the layout when the TMCC base is plugged in just touching the ground wire to the base still sends the track signal testing on 2 engines from 10's to low #'s or out of range. I tired a 2nd TMCC base instead and it did the same thing. A LionChief engine on the track turned on or off at no affect on the signal, just the TMCC base. The base was not plugged into the TIU. 

What I will likely do is to just connect the TMCC base to 1 loop of track and sidings for TMCC only engines with no wire connections to the DCS tracks on the main layout. 

kj356 posted:

….but did not affect the DCS signal. The Signal only went to out of range on the DCS remotes when I plugged in the TMCC base. 

You mean like this? (sorry for the ugly nasty voice! )

I mention the "brick" causing the issue and I meant to say the Lionel TMCC base. Carl Tuveson gave me some tips like moving the base to the farthest point away from the DCS system. It made it better but after a few years I forgot about the tip and moved the base right near the layout control area. Because I only have a few TMCC engines I chose not to run them at the same time with my MTH PS engines. I also wanted to run the TMCC engines by installing a wire near the tracks to carry the signal and not connected to the rails.

" on Sour mash and cheap wine " ??

Why go back to DCC when I have DCS!

Yes, it doesn't seem to be the norm here. Barry and I discussed the issue and Barry thought it might be enhanced because I only have 2 rails! I'm trying to think of ways to solve the issue here. Moving the TMCC base to the farthest point away is just a test. Not sure what brings this on for some users?

I added an upper loop of 3 rail track. The problem popped back up. I traced the issue and found that the TMCC signal got connected thru a common TIU and Z4000 running both 2 rail and the 3 rail loops. I have separated them now using more PH180 bricks for the 2 rail and running the TMCC alone.

" on Sour mash and cheap wine " ??

Why go back to DCC when I have DCS!

There is an identified issue where it's possible that the TMCC signal will affect the DCS signal.  It's not a certain thing, and it does seem that the layout wiring has a significant effect on the issue.  Adrian has posted in some detail about the interactions, and he's also set about trying to engineer a solution to the issue for his club.  I ran DCS and TMCC on around 180 feet of track (Fastrack) in my old house with no issues of interaction at all, so it's not a sure thing.  Also, tons of folks run DCS and TMCC/Legacy together with no issues.

Does common ground wiring/tying all the ground wiring together help? I have 12 gauge wire that all the track common ties to (just a basic loop under my layout with drops from the track). Power/hot wiring is all star pattern. I get a DCS signal of 10 everywhere and no TMCC signal issues. There is one TMCC locomotive that will drop the DCS signal to 8, and that's a Lionel 6-18130 Santa Fe F3 from 1996 with one of the original LCRUs. All my other TMCC locomotives are ERR AC or Cruise Commander equipped and have no effect on DCS signal strength. 

Santa Fe, All the Way

I believe you have identified one possible issue.  The DCS signal is basically a transmission line, and it uses both the hot and common rails to transmit the signal.  For optimum results with DCS, the two lines should be roughly the same length as they go to the individual star distribution points. 

Keep in mind that just because you are getting 10's for signal strength, that doesn't mean the DCS signal is being distributed in an optimal way.  The signal strength test just measures how many dropped packets there are in the two-way conversation.  You can be on the hairy edge and still get 10's.

My guess is if you properly wired the grounds to the star distribution points, you'd have better luck and less interference with the TMCC signals.

Engineer-Joe posted:

...... I also wanted to run the TMCC engines by installing a wire near the tracks to carry the signal and not connected to the rails.

I doubt this would work.  I understood that the receivers in TMCC/Legacy locomotives need both inputs to work properly.  The “track signal” which comes from the outside rails through the wheels of the locomotive, and the radio wave which gets picked up by the antenna in the engine transmitted  from the base.

I tested it with just a long straight track that I set up. The wire was just laid near the track. The TMCC engine responded and ran correctly. I never tested it further. I wanted to string up a line on telephone poles that ran around the layout.

 Try it yourself to test!

" on Sour mash and cheap wine " ??

Why go back to DCC when I have DCS!

While in a simple test this might work, for a reasonably sized layout, it's very doubtful that this would be effective.  Larger layouts frequently have issues even with the track signal connected, relying on weak capacitive coupling would surely exacerbate that issue.

FWIW, I've had limited success running stuff with Legacy on my test bench with no connection if the layout track is energized.  It's somewhat spotty, but even 10-12 feet away under certain circumstances it will sometimes work.  However, that's not the basis for a reliable layout with TMCC/Legacy, at least IMO.

I have probably somewhere around 100 engines running with DCS. I have maybe 2 or 3 Atlas 2 rail with TMCC? (1 I can think of). It's not worth me fighting the TMCC signal destroying the DCS.

 When I run my few 3 rail TMCC/ Legacy engines, I connect the base to that track only. Otherwise, the base is unplugged.

I only posted to back up his claim of the base wrecking the DCS signal. It does happen. Sure an engine(s) can do it too.

" on Sour mash and cheap wine " ??

Why go back to DCC when I have DCS!

You are correct Joe, the TMCC signal can affect the DCS signal.  It's a difficult issue to solve, primarily due to the two-way nature of the DCS signal.  If it were just a one-way communication like TMCC/Legacy, it would be a piece of cake to resolve this.

gunrunnerjohn posted:

I believe you have identified one possible issue.  The DCS signal is basically a transmission line, and it uses both the hot and common rails to transmit the signal.  For optimum results with DCS, the two lines should be roughly the same length as they go to the individual star distribution points. 

Keep in mind that just because you are getting 10's for signal strength, that doesn't mean the DCS signal is being distributed in an optimal way.  The signal strength test just measures how many dropped packets there are in the two-way conversation.  You can be on the hairy edge and still get 10's.

My guess is if you properly wired the grounds to the star distribution points, you'd have better luck and less interference with the TMCC signals.

You're probably correct but since I rarely run more than one locomotive on a loop at a time I'm not too concerned about the signal loss. Plus I'm not in a hurry to crawl around under my layout rewiring. 

Santa Fe, All the Way

kj356 posted:

 The DCS system runs near perfect with no TMCC plugged in???

And the TMCC equipped engines do not seem to be a problem when the base is not plugged in?   

If the TMCC engines are sitting on powered track without the base plugged in, wouldn't they take off at track voltage speed?

Remember that any equipment that takes track power could also be a culprit. Cabooses, lighted cars, sound cars, powered cranes, etc., etc.

" on Sour mash and cheap wine " ??

Why go back to DCC when I have DCS!

kj356 posted:

For some time I have been having some severe signal problems with my DCS system. Have an extensive fleet of  MTH engines on the main layout; engine not found, engine or repeat sounds when a soft key pushed or unresponsive buttons and difficulty operating lash ups. I had gone through the DCS guide rewired it with star pattern added lights to the distribution power block etc. as recommended in the book. I have been moving TMCC engines off the main layout . Last night I moved my 2 remaining TMCC engines to a siding turned off the power to that siding and unplugged the TMCC power supply. Instantly everything DCS worked perfect. No more signal problems. I went looking for a 22uh RF choke for the TMCC engines that was recommended in the DCS guide. It was suggested a 4 amp choke but the electrical shop did not have any that big will keep looking. Happy to be running trains trouble free again now. 

So the answer to making DCS work properly is to open up perfectly operating TMCC locomotives and install RF chokes?  

Seriously?  

George

TCA, NMRA, PRRT&HS Modeling the PRR Panhandle Division between 1948-1957.

G3750 posted:

So the answer to making DCS work properly is to open up perfectly operating TMCC locomotives and install RF chokes?  

Seriously?  

George

No, you can send me all your TMCC/Legacy locomotives, I'll take good care of them.

gunrunnerjohn posted:
G3750 posted:

So the answer to making DCS work properly is to open up perfectly operating TMCC locomotives and install RF chokes?  

Seriously?  

George

No, you can send me all your TMCC/Legacy locomotives, I'll take good care of them.

Don't hold your breath, John.

TCA, NMRA, PRRT&HS Modeling the PRR Panhandle Division between 1948-1957.

When I turn on the power with the TMCC base unplugged and DCS on the track the TMCC engines start up but do not move in neutral, but if I had the breaker trip on off if a derailment or something then the trains would take off like a rocket I only tried it to see what would happen with the TMCC trains on the track and the TMCC base unplugged this is where I am getting the signal problems not from the engines sitting on the powered section of track. Thanks for suggestions for now have the base unplugged and TMCC engines off on sidings with power off to sidings can plug in the base to run the TMCC trains and limit what I run in DCS on other tracks. At some point may try to reorganize the railway and change some tracks around so I have a TMCC only loop as many many other DCS trains on the other parts levels of the layout. 

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