Legacy connection kills DCS

John,

You can't be stumped on this one, can you?

Do any of the modules have isolated outside rails messing with the legacy signal?

 

Just for my knowledge, are the frequencies far enough apart to avoid intermodulation?

I assume that they are, but I don't know the DCS frequency.

 

 

John. I have also noticed that block contamination kills the DCS signal. I'm not sure if this is a PS3 thing or a rev L thing.

I haven't noticed anything with Legacy. How do you have it tied in?

Dave

Well, I just got the wiring fixed so that the TIU was properly tied into the power districts, then found how bad the Legacy kills us.

 

The frequencies are 455khz for Legacy and 3.27mhz for DCS.  I've not experienced any issues relating to Legacy in any other location, that's why this throws me.

 

Dave, the Legacy is just connected to the outside track, same as any other installation.  The TMCC/Legacy stuff runs dandy.  The difference is amazing, and I can't repeat it here, disconnecting the Legacy doesn't seem to affect the DCS at all.

 

You'd be surprised what I can be stumped on.

 

Is the TIU and the Legacy base connected via the serial cable?  If so does removing it may any difference?

John,

We hooked up my Legacy base on Clem's layout last Saturday.  He is DCS and his layout is folded back on it's self to make a single loop of track 3 scale miles long.   Over half of it looks like a double track main, but is not.  He uses all four channels of one TIU, rev L - I believe, as four blocks on his loop.  We connected the four black TIU output terminals together and connected the Legacy base there.  We ran up to six trains at a time, a mix of DCS, TMCC, and Legacy.  The only problem was when Clem tried to bring out his "Lashed up MU" DCS train.  We lost control of the DCS engines on the track.  Makes for interesting times, thanks for the DCS emergency stop - kills all power to the track.  Clem has seen the MU problem before and recognized it.  You may need to talk to him to get more details. We never checked signal strength.  You can see his layout on the "Detroit 3 Railers" October Meet thread.

No serial cable, and I even relocated the TIU to a more central location to minimize the runs from the TIU to the track connections.  That's when I discovered the screwed up wiring that was killing the signal on half the layout.  After fixing that, I discovered the Legacy issue.  To be more correct Harry actually told me that he saw the effect before, and when we disconnected it, it totally changed things!  I hadn't bothered with it as previously disconnecting it didn't fix anything, but after working on the wiring, now I'm stuck with the Legacy connection issue.

 

I am going to try a different base when I get a chance.

Hi. Dan

our layout is set up about the same. We have about 600 feet of track or more.

 With a loop at each end. It is divided in to 4 power section. We noticed it more With the ps-3 engines than the ps-2. The.Ps-2 ran ok but not well Would loose signal at spots.

 About a month ago is when I found out about unplugging legacy.

I would let the MTH GUYS run for hour  then the Lionel for an hour. 

 

We were probably running mostly PS-2 engines, don't know as they were not all mine.  At home I have only one PS-3 engine and an I3A TIU.  The PS-3 engine is very flakey.  My PS-2 engines run fine.  Will try the PS-3 engine today, then hook the Legacy base back up.

Dan

Let us know how you make out?

Accomplished some testing, maybe a small drop in signal strength.

My layout is three and 1/2 loops ~ 80' to 130' long.  Tested my PS-3 Ann Arbor RS-1 30-20081-1 around two of the loops, no Legacy connected (had to get the Legacy engines and the Kadee height gauge, dead short, off the layout) signal strength was good.  I may have two blocks double feed from the TIU, will correct when I get home from York. I then parked the PS-3 where I had a signal strength of 10.  Added Legacy base, no change (complete shutdown and restart of layout).  Added 3 Legacy engines, no change.  Running two of the Legacy engines and the RS-3 around their loops I saw a small drop in DCS signal strength compared to no Legacy. I don't get repeatable signal strength measurements at the same point in the track as I run the engine around.  

 

Don't know if this helps.

 

Out of time till I get back from York.

Dan

Obviously, something more is at work in our situation, the signal strength went from 8-10 to 1-2!  Most of the time, we didn't have control of the locomotive on that stretch of track.

 

 

I would start with no Legacy engines on the track, add the base, and then engines.  May have one or two bad legacy engines.

Dan

We had no Legacy engines on the track.  Also, it only happened with the command base signal wire connected.  The command base was still powered on, just not connected.

 

 

Have you (or can you) try it with a different command base?

Chris, when I get back from York I'm going to do just that.  I don't know how the command base is killing the signal, but that's the first thing that comes to mind.  I may drag up a new Legacy base, Legacy Lite base, and an old BASE1, just to see what the difference is.

 

Hi John,

           I have noticed a similar effect on my home layout. Legacy kills DCS signal. 

Switching off Legacy base restores DCS signal strength. 

 I should really play around with it some more but I only have a couple of DCS engines. So I just tend to run them on a separate loop at the moment. 

 

Nick

I run my TIU in passive mode at home. I wonder if that would change anything?

Nick, nice to know we're not alone, but I'm not sure if that's good news or bad news!

 

Jeff, I happen to be running it in passive mode right now, but it appears it happened before in active mode.

 

Just when I was thinking of going Legacy   This isn't helping, Neither is the thread on bad 

legacy sets.

 

Clem k

What can I say, just sell all the DCS stuff.

 

Hmmm, maybe its a bug Lionel has engineered into the most recent legacy software upgrade.

 

So much for running "all brands of trains" from the dcs handheld..............

I run two rail mainly. So when I announced I was having troubles, it was assumed it was something to do with the two rail aspect.

 Carl Tuveson, had some helpful hints to get them to work together on two rail.

I ended up yanking my TMCC brick because I have so few Lionel engines. I also converted my off brands to DCS.

 I tried an experiment running TMCC thru a wire laid near the rails but not connected and it worked on a test track. I never went the extra mile to do the whole layout yet. I have enough MTH engines to satisfy my needs now.

 Sadly, a lonely Atlas TMCC switcher sits on a scrap of track waiting for her chance to run.

The Trackers have a dedicated neutral (common) for each of the three tracks, the commons are kept isolated from each other on the modules. The ONLY place they are tied together is at the outputs of the TIU where there is a tie from the four black posts to the Legacy base. It has worked for us with no DCS signal degradation.

 

Steve

Well, next week I hope to do some more experiments and see if I can learn anything new.

 

Dan,

 

My engine was PS3 and ran fine with Johns Legacy/TMCC engines, FWIW.

John, Did you get any further with the DCS signal degradation? 

 I was playing around with it today as Mason's Blue Comet is PS3. 

Our layout is wired as Steve describes the Trackers layout.

Each track has it's own common and they are only tied together at the TIU. With the Legacy common connected to them.

With Legacy off DCS signal strength is 10. With Legacy on signal strength drops to 2.

 

Nick

Not so far, company for the holidays, no time to tinker.  I spend all my "tinker" time with the Big Boy.

 

Don't blame you John. Enjoy the Big Boy

I was under the assumption that DCS only needed one outside rail and Legacy needed two.

 

How does that fit into your wiring Nick?  Perhaps you are getting two rails of DCS signal.

 

Best wishes for the holidays!

Carl, I never heard that before? G

Guns,

   I do think you are going to find that once you change Legacy Base units you may loose your problem.  When we had the fair size office/game room layout we had this happen with one of the legacy bases, it kept me from purchasing the legacy system for quite some time.  Independently the bases worked fine, the DCS worked with one but not the other, Legacy base.  Jim returned the legacy Base, got a new one and everything then worked fine. I was reluctant to post about this incident because I thought it was just one defective Legacy base unit, now hearing about this makes me wonder just what the heck is happening.  The thing is we never had this happen on any of the smaller DCS/Legacy layouts, just the one larger layout.

PCRR/Dave

G,

I based that on what I know of how the signal radiates from the rails. Legacy should optimally radiate from both outside rails and through the wheels and DCS from only one. Am I wrong on the DCS?

 

Example-Lionel ties their outside rails together in FasTrack. MTH leaves the outside rails separated in RealTrax.

 

L & N doesn't state if the Trackers tie the outside rails together or use only one.

 

 

 

 Edit: ok, the trackers tie the outside rails together , so I assume that blows the DCS on two rails issue out of the water, because theirs works.

I had lionel tmcc with the old system 1st and now with legacy base.  The lionel works perfect but with the  new dcs  Dcs system is rev l and has 5.1 software I have trouble with dcs engines on the track with a lionel tmcc engine getting too close to each other (6 inches or less) the dcs engine will not follow commands given to it.  the handheld says engine not on track.  Also I have always had signal strength weakened after the dcs engine goes through one switch.  but after it gets to the next block all is fine again.  I have by passed the switch with individual 18 gauge wires for each track and shows 0 ohms R on the digital multimeter by signal is very weak in that section.  I have limited my dcs engines to 3 because of this and all the rest are trouble free lionel.

The TMCC/Legacy rail signal isn't designed to be radiated anywhere, it's a direct connection to the ground side of the TMCC receiver.  The antenna that picks up the radiated earth ground side of the signal is the other half of the signal.  The antenna does NOT receive the track side of the signal.

 

DCS obviously runs on both outside rails or one, but since virtually all three-rail equipment has all the axles shorted, it's coming in on both sides in any case.   The other half of the transmission line is the center rail.