TMCC signal loss

Joe:

If I remember correctly from my own experience; if the locomotive stops and the front lights start blinking it means you have issues with the signal from the top track mixing in with the signal from the lower track. It is not really a loss of signal but too much signal. The locomotive on the lower track receives too much info too fast (I think it is frequency related) and decides to shut down. This is what the ground wire fixes. 

The ground wire stops the signal on the top track from propagating below it and mixing with the signal from the lower track. I first read about the issue in an OGR article written by the NJ Hi Railers. They solved the problem with copper foil underneath their scenery. I used aluminum foil under mine. It sounds like it is too late for you to go this way so best thing to do is run a wire under the top track (does not need to be bare wire) and connect to an independent ground (not track ground if I remember correctly). I don't know how your top level track is laid (roadbed, ballast, elevated structure etc), however the wire does not need to go directly under the track just underneath it somewhere.

I don't know if wire needs to be on both sides of the track or one side only. I will let the experts answer this. Since the signal radiates out in a circular pattern one would think one wire is enough.

You can also do a search of the Lionel YouTube videos. There is one where the problem and solutions are discussed.

Let us know how you make out.

Joe

What is your track?  What are you using for power?

Joe is correct.  Wire over the track works great.  Many guys see the light blink and think they have bad signal.  What they have is conflicting signal like Joe pointed out.  Anyone who has this issue should talk to someone who has been involved with the issue and scored.  

Thanks guys for the information. I just turned off the power to the lower loop and the TMCC engine ran great on the main. So I then turned off the power to the main loop and ran the lower loop and engine ran poorly, wanting to stop. I have three 180 bricks and using 3 channels on the TIU, 2 on the main 1 on the lower loop. 

Thanks again.

You don't need a large wire 20-22 awg will work. It should be connected to earth ground, the round prong on the receptacle, the screw that holds the cover on.

Run it under the top track. Dale Manquen sells the Pin5 connector to the command base serial port. he's debugged some large layouts.

One note:  Make sure that the cover of the outlet is really earth ground if you use that for the signal wire.  Many older houses are not wired properly, which accounts for some instances of poor TMCC performance.

That is very often over looked John.  Try to go to wall outlets and not power strips.

If you are in a basement and have access to a water pipe, wrap a wire around the pipe and use that as a ground source.  That worked for me.

I'm a believer in having both outside rails tied together whether DCS or TMCC and all transformers phased together with a heavy 12 gauge wire on the "U" connections or commons.  I know this may not be part of your problem. 

I am with you Gregg.  Try telling that to some people.  My bet is your trains run great.  All you train guys in Canada do things very similar and have great results.

I am not having a problem, but would the heavy gauge wire apply to the between one's Legacy base and TIU outputs? Sounds like it might. My Legacy base and TIU are only about 3 inches apart, but I got cheap here and used a skimpy little #18 wire. If it would be better, I will fix it with a larger wire to match the rest of the #14 wiring going out to the tracks. I never really gave this part much thought, just hooked it up with what was laying around.

Doesn't matter. 3 inch 18 ga is fine.

I agree with Gregg and Marty on tying outside rails together. I always run ground wires to both rails (not on all track sections - just where power is applied).

Which brings a good question (thought outside the subject of this post) - I have noticed with lighted cars that some tend to blink on/off running down the track. If I just slightly tilt one of these cars I can make the light go on and off. I don't think this is a function of the outside rails not be grounded. Anyone got any good ideas?

Thanks

Joe 

Quite possibly the way the wheels ground through the trucks.  Sometimes with this issue, running a wire from the truck frame to the car frame will help.  It really depends on the design of the trucks and how they conduct the power from the wheels to the frame.

Thanks John - I will try running a wire and see what happens.

Joe

Thanks. The devices are 3 inches apart, but the wire is more like 10-12 inches long. I am thinking this probably doesn't matter much either. It has actually been working very well for over a year this way.  

Joe 

If you put a strip of copper under the top track it will push the signal down around the track. The RF signal is forced up off the bottom track and it gets out of the range of the TMCC antenna. This problem is normal for any RF signal and TMCC is 455 KHZ FM signal. I have used this fix on a number of layouts and it does work. The copper strip is grounded to electrical ground. 

I kind of like Dale Manquan's description best...

 http://www.trainfacts.com/trainfacts/?p=317

Gentlemen,

    I have been using Marty F's technique running one Legacy Connection on the opposite outside rail of the DCS set up, and also running it thru the DCS out side rail, connecting in this way I get a great Legacy signal.  As usual Marty is a head of the curve on most all this stuff.

PCRR/Dave

When I wired the San Diego 3R display I had to put the copper strip on the bottom of the top board under the track and that corrected the problem. I also recommend that this be used on a friends layout who has passed away and it work there as well. I have used it on anumber of layouts and it works. 

Sorry to get off topic but I notice something today when Dave_C brought over his legacy setup.  I've been having reception issue with one engine(which I've final fixed).  I notice that the Legacy signal was noticeable stronger than my old TMCC command base. The engine in question received commands without skipping a beat with Legacy.

Anyone else seen this?  Better signal with Legacy over TMCC command base?

I have noticed that too. I know that Lionel change the circuitry but also updated the software and the I feel contributed to the change more. The software is the key to this which is the programing of the PIC which controls the TMCC signal and they did change the frequency from 27 MHZ to a UHF frequency and that would contribute to the  increase in signal strength. 

The signal to the engine was always 455 KHz, the frequency changed was from the handheld remote to the base. The TMCC handheld is 27 MHz (note the long collapsible antenna rod), and the Legacy handheld is I think 2.7 GHz.

So if the signal is better to the engine, then the output of the Legacy base may just be stronger than the same frequency signal output of the TMCC base.

Also, I have seen a number of Legacy bases that had a very weak output. This is one of the possible issues with the Legacy base as well as the common charging issue. The weak signal issue is not chronic like the charging issue which has been addressed, but it is something to think about if you have a general signal problem getting to the engines.

If you suspect weak track signal, here is a treatise on it...

http://www.trainfacts.com/trainfacts/?p=691

I suspect the tuning of the TMCC command base as Chuck points out.  Having measured the output frequency of the TMCC and Legacy base, I've noticed that the Legacy is rock solid on frequency, but the TMCC bases are all over the map and they drift as they warm up as well.

So it's not an issue of signal strength but an issue of signal accuracy.

John,

I wanted to ask you about my Weaver Pacific I was having reception issue with.  ERR cruise equipped, terrible  reception form day one.  Even isolating the tender shell just in case there was a short I couldn't find and five R2LC08 boards with no improvement.   The fix was R4LC board.  What's the difference with the Radio on these boards?

Gary, I'm not aware that any significant changes were made to the R4LC over the R2LC as far as the signal reception, so I can't say.  The biggest difference I'm away of is the R4LC has a different processor with more memory, that was obviously done to add the Legacy code for the earlier Legacy locomotives.