DCS and gargraves switches

Assuming these are twin coil switch machines, the coils act as chokes to RF, killing the DCS signal.

I use switches as track block locations for that reason.

Also, if you use Aux power instead of track power for the switch machines it should remove the problem.

TMCC / Legacy is a radio signal through the air to the train, the track is just the ground. That's why it doesn't care.

Why will a dcs signal not go through my gargraves switches.  The tmcc signal gets through fine but not dcs? 

This question seems familiar. I believe that you've asked it before and I requested to know exactly what you meant by "would not go through". I don't remember getting a "straight" answer.

I should mention that there are two legacy engines sitting on the same track that I want to put the dcs engine.  Would they interfere with the dcs signal?

Yes, they absolutely could degrade the DCS signal, as you would know from the many, many times that this has come up, if you searched the forum.

Further, this is covered in The DCS O Gauge Companion 2nd Edition, which I believe that you have purchased. (If you haven't, you most likely should based on the questions that you tend to ask.)

If you have the book, what you want to know is on page 152 - check it out!

This and a whole lot more is all in "The DCS O Gauge Companion 2nd Edition", now available for purchase as an eBook or a printed book from MTH's web store site! Click on the link below to go to MTH's web page for the book!

Russel,

TMCC / Legacy is a radio signal through the air to the train, the track is just the ground. That's why it doesn't care.

Not exactly.

Those TMCC and Legacy signals are, indeed, radio signals. However, they are imposed on the outside rails of the track, which then becomes a transmit antenna. The engine does pick the signal out of the air, however, it's a very short trip through the air - about an inch!

Barry, I'm guessing you haven't read Dale Manquen's page on how TMCC functions.  The track signal is NOT picked up by the antenna, which is why when you short the antenna to the frame of the locomotive, TMCC ceases to work.  The antenna is actually for part of the signal that is radiated by the earth ground connection through out your house (and the world I guess).

Quote from TMCC Signal Basics

We must stop here to dispel Myth Number 1 – “The antenna on a TMCC locomotive picks up the Track signal.” As we just concluded, one side of the receiver’s input connects directly to the outer rail, and hence the Track signal. If the antenna also picked up the same signal, there would be no voltage difference and no resulting current flow. The antenna IS NOT PICKING UP THE TRACK SIGNAL. If not the Track signal, then what is the antenna receiving?

Ironlake, I'm not going to get involved with TMCC, but Gargraves switches are all over my layout and cause no problems.  I will state that each of the 40 or so is used to define the ends of 3 blocks, by severing the bus under them.

John,

The track signal is NOT picked up by the antenna

Sorry, however, I never said anything about a "track signal", rather I said that the outside rails become a transmit antenna. You should read a bit further down in Dales paper.

First, the excerpt from Dale's paper that you quoted discusses The antenna on a TMCC locomotive, not that of  the track.

Several paragraphs down he states the following:

We can consider this path from the thumbscrew through the track and into the locomotive frame as one half of the transmitting antenna for the Command Base’s output signal. 

I stated:

...they are imposed on the outside rails of the track, which then becomes a transmit antenna.

Pretty similar, wouldn't you say?  

Pointless to argue this, but go back and read your original statement.  The signal from the ground to the antenna goes a lot farther than an inch, the track is common with the feed directly from the command base.  At best, you described half the signal transmission path, and the part that is generally problem-free.

The statement is misleading at best, and totally ignores the real problem  that sometimes occurs with TMCC signal propagation, that being the signal that goes to earth ground and is picked up by the totally isolated TMCC antenna.  I know of nobody that has a problem with the signal from the track to the locomotive frame.

John,

The statement is misleading at best, and totally ignores the real problem

I'm very sorry that you feel you were misled, and I truly don't share your concerns regarding "the real problem", whatever it may be.

Now, you'll need to post one more time to ensure that you get the last word, as you usually do.

As long as you're not contentious, I promise not to respond.

gunrunnerjohn,

   Remember the question was why the DCS signal does not go thru, not the TMCC,

actually Barry is correct, however I do believe this problem is being caused by the TMCC engines degrading the DCS signal, in the 1st place. 

PCRR/Dave

The last word.

Dave, I've experienced a couple of Legacy locomotives stepping on the DCS signal, I have the chokes now, just haven't gotten them in.

GRJohn,

   Roger that

PCRR/Dave