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We are using the term "ground plane" inappropriately in our TMCC/Legacy discussions. A ground plane is a large conductive area at zero volts reference potential. In our case, the earth-ground leg of our signal transmission signal is neither one of these.

Our ground plane is not "large" in relation to the wavelength of our radio signals, which have wavelengths that are .4 miles long.

Our ground plane is not at zero volts reference potential. In fact, the earth-ground leg of our signal transmission system is the PRIMARY RADIATOR of the airborne radio waves received by our locomotives. If you had to choose a "zero volts reference", you would be much more accurate to pick the outer rails of the track. This is the conductive surface that is connected to the frame of the locomotive and the ground side of the radio receiver inside the locomotive (and the negative side of the regulated power supply inside the locomotive.)

Here are some suggestions for a new more descriptive term:
Supplementary radiator
Added or additional radiator
Extra radiator
Ground signal radiator

I think the term should include "radiator" to help people understand that there is a signal coming off of this conductor.

How do you vote? Any other suggestions?
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quote:
Originally posted by MartyE:
It means everyone has been calling it that so long that no one else will know what your talking about until you say "You know...ground plane". Ohhhhhhh.


I get what you are saying, but I think it's better to be correct. That way, even folks who don't run trains or normally use this forum will better understand what we're talking about. The term ground plane when referring to the ground wire radiator has bothered me from the first time I read it. I don't think it's much to ask for folks to learn a descriptive name, one that describes what it is and does.
Dale, I appreciate your very correct analysis of the incorrect use of the term "ground plane" as it relates to TMCC/Legacy. However, no matter how "wrong" the term might be, it is FAR TOO LATE to change this term now. Everyone knows the term and knows what it means. That's what counts.

This is in the same category with my crusade to change that God-Awful term "Lashup." It is too late to change that, too.

Now you will have to excuse me, I have to head for Home Depot to buy some more rope. I'm gonna LASH UP a couple of diesels tomorrow. Hope I don't bend the hand rails. Roll Eyes
quote:
Everyone knows the term and knows what it means. That's what counts.


Rich, the problem is that everyone DOESN'T know what it means. That is proven quite conclusively by Mike Reagan's video!

Lionel is responsible for much of the confusion regarding track signal problems. My personal opinion (to which I hope I am entitled here) is that the people at Lionel NOW really don't understand how it all works. Maybe the guys at Liontech that "invented" all of this years ago had a good grasp of it, but the true nature of the signal has never been accurately presented to the Lionel customers, and that handicaps the customers when it comes to solving their problems.

Things continue to get worse as we have variations in locomotive receiver sensitivity. I would expect Lionel to have some "standard" that must be met by every new design. I am talking about a real scientific measurement of minimum field strength sensitivity, not just that it runs on the Lionel test track.

My biggest fear is that the folks designing and maintaining the Lionel products really believe their own bunk. How can you build great products on an incorrect basis?

We should give the newcomers to our hobby a chance to start out with good information so that they don't sour and leave us because they have frustrating technical problems. Hopefully, TMCC/Legacy will be around for a long time, and these newcomers will be the core of our hobby when we are gone.

If we "lashup" our efforts, maybe we can make a change. Meanwhile, I will take my airplane model down to the grinding wheel and make some "ground plane". It gets a bit dusty if ground too fine....
Rich, not knowing any better, I used the wrong term for MU. But you corrected me on that some time ago and since then I do use MU. Thanks. I think it's time to fix the ground plane error. It's a ground wire that radiates.
I'm using the correct description for MU. I think you can understand that, and I as an EE and Ham radio operator, understand this.
Dale,

Despite our "irreverent" usage of the term "ground plane", I think we should evolve to use the correct terminology! Because "ground plane" has come to be widely accepted, it will mean going through a transition, perhaps by using both terms for the first time it appears in a post and then the "correct" term in subsequent sentences. If this is done regularly enough it will eventually catch on, especially if it is adopted and used by the more knowlegeable members of this forum.

That being said, I like the term "Ground Signal Radiator" since it includes the word "ground" that we have all come to know and love.........
quote:
Originally posted by Dale Manquen:

Things continue to get worse as we have variations in locomotive receiver sensitivity. I would expect Lionel to have some "standard" that must be met by every new design. I am talking about a real scientific measurement of minimum field strength sensitivity, not just that it runs on the Lionel test track.

My biggest fear is that the folks designing and maintaining the Lionel products really believe their own bunk. How can you build great products on an incorrect basis?

Dale,

We have test equipment to test our designs including the radios, and we do and hold our designs to high standards. Additionally we have many layouts for testing, Neil's being one of them, to verify designs in actual operating conditions - because meeting specs in a lab is not 100% guaranteed to catch all problems. Furthermore, I don't consider my efforts "BUNK". I don't appreciate your comment one bit.
Possibility:
“Counter Poise Radiator” counter poise is the term used in AM radio broadcast antenna systems. CPR refers to the wires laid on or in the earth at the base of each AM radio tower. The copper wires work best laid on top of the earth but are usually buried 8” or more to protect from being stolen. The current into the tower is the equal to the current into the ground system. The current into the outer rails is the same as the current into the power line ground wires.
Denny Todd
quote:
Ground signal radiator

Dale:

I read the above responses and agree with you that if there is an error, and something is being called something that it is not, it should be corrected!

I vote: Ground signal radiator

By the way, whenever I see a post by you, I always read it with great enthusiam as I know I will likely learn something new!

Thanks for your very valuable input to this forum and our great hobby!

Stan
This is getting too technical for most TMCC users. Denny, what do you call your radiator (tower) if somebody walks out into your field and connects the ground of his receiver to one of your radials. OK, now take the whole systen, tower, radials, and receiver, turn it up-side-down and stick it back in the ground. Now what do you call the radiator. That is what TMCC does.

As long as Lionel continues to insist that the signal radiates from the track to the receiver you are not going to convince the average user. Ground Signal Radiator would seem to be a good term but that is too long and confusing for most users. Shorten it to Ground Radiator.

I am sorry Lionel, but with all due respect, how can you insist that any radio receiver will work with it's receiving antenna picking up it's signal from it's ground terminal. If that were the case, just connect the antenna to ground.

Al
quote:
Rich, not knowing any better, I used the wrong term for MU. But you corrected me on that some time ago and since then I do use MU. Thanks. I think it's time to fix the ground plane error. It's a ground wire that radiates.
I'm using the correct description for MU. I think you can understand that, and I as an EE and Ham radio operator, understand this.



The problem again as I see it, it would only apply to this forum. Ground plane is used, even in it's generic state, pretty much everywhere with TMCC. Same as lash up.

If I had to choose I guess Earth Ground Radiator would even be a little more precise. Especially since so many people already use ground incorrectly to describe the common for the layouts.

I just think it will add to the confusion because of it basically became so widely used but I do see Dale's point to be technically accurate.
quote:
I am sorry Lionel, but with all due respect, how can you insist that any radio receiver will work with it's receiving antenna picking up it's signal from it's ground terminal.


Where is this coming from? Pin 5 on the command base computer port is tied to the ground prong on the wall wart transformer. The wall wart is plugged into the three prong outlet on the wall which, if the house was wired correctly, goes all the way back to the load center/fuse box where it (aka the ground wire) is tied to earth ground. I don't think I've ever heard of or seen a radio transmitter that had the output tied to earth ground and actually worked?
quote:
Originally posted by HOSO&NZ:

As long as Lionel continues to insist that the signal radiates from the track to the receiver you are not going to convince the average user. Ground Signal Radiator would seem to be a good term but that is too long and confusing for most users. Shorten it to Ground Radiator.

I am sorry Lionel, but with all due respect, how can you insist that any radio receiver will work with it's receiving antenna picking up it's signal from it's ground terminal. If that were the case, just connect the antenna to ground.

Al
Absolutely correct Al; BTW: Lionel Engineering does not "insist". The signal does not radiate from the track into the Loco antenna. Those on this forum that understand this, kudos to you. I have designed many radios for Lionel (and ElectricRR before my time at Lionel); and I do understand the receiver and the signal paths.
quote:
Originally posted by chuck:
quote:
I am sorry Lionel, but with all due respect, how can you insist that any radio receiver will work with it's receiving antenna picking up it's signal from it's ground terminal.


Where is this coming from? Pin 5 on the command base computer port is tied to the ground prong on the wall wart transformer. The wall wart is plugged into the three prong outlet on the wall which, if the house was wired correctly, goes all the way back to the load center/fuse box where it (aka the ground wire) is tied to earth ground. I don't think I've ever heard of or seen a radio transmitter that had the output tied to earth ground and actually worked?


Interesting enough, the house wire neutral or return path goes all the way to the circuit breaker panel and attaches to the same buss bar that the ground wire from the receptical ties too. Which is the same bar that the power company neutral is tied too. Of course there is a separate ground cable that attaches to the same bar and then into ground rods around your house. G
I have personally seen Jon Z's test equipment for the TMCC signal about 3 years ago. While I didn't personally play with it, or receive a demo I certainly seen it and know Lionel does have a engineering setup to test.

I have had to fix TMCC issues on my own layout and a few of my own TMCC conversions could use some more work on the Antenna. These are my own upgrades and not from factory.

Jim
Chuck, it comes from the way the receiver is connected. Just like a transmitter every receiver has two antenna terminals. One is usually connect to ground and the other is the antenna you see. The receiver in the engine is no different, one side is connected to ground and the other is the one everyone talks about. The problem is that the ground for the receiver just happens to be the same outside rail that everyone seems to think transmits the signal to the antenna. You can use the outside rail for the ground side of your signal or for the transmit side of the signal but not both at the same time. Since the TMCC base unit connects the transmit side of the signal to the outside rail or the ground side of the receiver in the engine. Where does the antenna in the engine get it's signal? It can't get it from the outside rail as noted above. Go back to the transmitter, the TMCC base unit. If the transmit side is connected to the outside rail and the other side of the antenna is the ground side then where is the ground side connected? The ground side (pin 5 on the connecter) is connected to earth ground through the wall wart and the building ground as you pointed out. Therefor it is the building ground, earth ground, that radiates or transmits the signal to the antenna in the engine. Now, since the building ground is the transmitting antenna to the engine is it really proper to call it a ground plane?

Hope I got it right, think I did. Its a long story and easy to get lost.

Al
Jon,
Perhaps I used the wrong word. Maybe I should have said persist. And instead of using the generic term "Lionel" another more specific term would be more appropriate.

Lionel service ?? recently released a video in which they talk about the antenna picking up the TMCC signal from the outside rail. Although I do not recall where, it seems to me I have also seen this idea expressed in some of Lionel's literature.

Lionel tries very hard and I am sorry if I misled anyone but someone representing Lionel seems to be perpetuating this idea.

How the system works and who says so, however, is not the subject of this thread. The subject was one of terminology.

Al
Good explanation, Al.

Jon, if you understand and endorse this explanation, are you in a position as Chief Technical Officer of Lionel to see that the recent video by Mike Reagan that claims "a halo around the track that is received by the antenna", "millisecond timing differences due to small path length differences", "timing pulse interference" and "a ground plane can reflect the track signal" has these items corrected?
Outside rails of the track are not connected to earth ground (or any other "ground" for that mater). They are connected to the "common" side of the transformer.

TMCC signal will function find without earth ground or an "envelope" of house wiring. I've set up a command base to be driven off of a computer UPS power supply and an SC-2 controller to be run off of another one. The two UPS units are not tied together in any fashion. Neither is connected to the commercial power grid. Both units are being driven off their battery packs and power for the TMCC equipment is coming from the internal inverter circuits on the respective units. The "U" terminal of the Command base was wired to a 20 inch piece of brass tubing. A "cheater" was placed between the three prong plug on the wall wart and the the outlet on the UPS . A wire was run from the lug on the cheater to a pizza pie plate that was placed under a plexiglass "table". The piece of brass tubing and the SC-2 were placed on the upper surface of the table. The SC-2 had terminal position one wired up with a pair of LED's and a small battery pack to drive them.

I was able to "throw" the switch points on the SC-2 with no physical connectivity between the components. I can't tell which side of the command base was providing the signal. I know that both wires had to be connected as stated or there was no signal propagation. I know the SC-2 was able to properly receive the command signals and act accordingly even though there was NO physical or electrical connectivity between the devices. The signal/commands were propagated by RF through clear air. No wheels, no wires, no track, no envelope. Just air.

This equipment was set up on my driveway about 40 feet from the nearest active circuit in the house. There are no power lines in the area (power is fed by underground lines and comes in from the back side of the property which is about 120 feet away). There is no re-rod in the concrete, no street lights. Data communication is provided from the back side of the property, same distance/routing as main power.

I chose to use the SC-2 as a test receiver because it doesn't require access to the track to function AND it is an extremely low power device, easily driven off of a back up UPS. Command base is not quite as efficient but was still easily powered by a UPS.

There is a lot of double duty usage of wires/components with the locomotives and dummy sound units. It gets very hard to tell what parts are being used for what. The people who developed this system came up with a very novel way use of em to propagate signals.
I guess thats why adding more antenna to an engine seems to help at our club. It's like putting your hand over the engine to make it go. I still think TMCC should be redesigned that when the engine loses signal the engine should keep moving at the same speed like DCS instead of stopping or going full speed.
Jim D.
Interesting about SC-2s, I had been using the wall warts to power them and had a variable response to programmed Routes. Often missing some of of the switches when selected. I did have a ground wire from pin #5 of the DB9 on the Legacy base draped across the top of them which helped. I had to set the delay between switches on a route to almost 2 seconds. Then it still missed a switch once in awhile.
I decided to power them with a CW80 connected to the aux power of the SC-2s (cut loose from the switch #1 position) and connected the U terminal of the CW80 to the U terminal of the layout (which is connected to the Legacy base. They work flawlessly now and the delay is set faster to 1/4 second or so.
quote:
Originally posted by Dale Manquen:
Good explanation, Al.

Jon, if you understand and endorse this explanation, are you in a position as Chief Technical Officer of Lionel to see that the recent video by Mike Reagan that claims "a halo around the track that is received by the antenna", "millisecond timing differences due to small path length differences", "timing pulse interference" and "a ground plane can reflect the track signal" has these items corrected?
Dale,

I will mention it to him. Mike is trying to assist the hobby by the operational videos that he is making; in the grand scheme of things he is doing a great job. He is not a design engineer by trade; so once in a while he does not have the theory 100% correct. I don't think it is something to get too worried about.

AL, As far as the thread about terminology syntax, agreed - however this thread by inference relates to what the terminology means as well. You received my point, that Lionel is too generic. As a matter of fact, I endorsed Dale's explanation of TMCC signal operation for the last Legacy meeting; as this topic comes up time and time again. Basically I was complimenting you on your explanation. It is quite exact and insightful when you stated:

"I am sorry Lionel, but with all due respect, how can you insist that any radio receiver will work with it's receiving antenna picking up it's signal from it's ground terminal. If that were the case, just connect the antenna to ground."

It would be so nice to connect the antenna input to the track common in the loco! But it won't work! So the antenna input on the radio cannot be picking up the track signal.
quote:
Originally posted by Jim D:
I guess thats why adding more antenna to an engine seems to help at our club. It's like putting your hand over the engine to make it go. I still think TMCC should be redesigned that when the engine loses signal the engine should keep moving at the same speed like DCS instead of stopping or going full speed.
Jim D.
Jim, I am curious: what happens in a DCS loco when you lose contact and it continues to move? How do you stop your train from crashing? How do you blow the horn, how do you control any function? How do you get the loco back under control?
Jon,

I think there are advantages to it stopping to prevent runaways and stopping works for me. What I have heard from others is that they are worried that when a TMCC engine stops due to lack of signal and one behind it continues to run a collision will occur. Not sure which one is more likely to occur, a train coming into a siding and loosing signal and running off the end (DCS), or a train stopping on the loop due to signal loss and their being one behind it and running into it (TMCC).

Question does the TMCC emergency stop button work on all engines on the track or only the one that is selected in the Eng ID?
quote:
Question does the TMCC emergency stop button work on all engines on the track or only the one that is selected in the Eng ID?


It stops all TMCC engines or anything else receiving its commands from the base. Including TPCs, modern ZWs, and Powermasters.

On the question of which do I prefer the engine to stop or keep moving... I'm used to it stopping. Just what I got used to. Then again can't say I have too many issues with either system for this to be a problem.
Jon, if you are interested in any outside help, I would gladly volunteer to help with the preparation of an "application note" that embodies our current understanding of track signals and solutions to problems. I would expect that others here on the Forum might also raise their hands.

This new perspective has been evolving over the last couple of years as we broke free of the old "halo" model and began looking at the real science. I am pleased to have been one of many participants that have helped this along, and I would hope we can bring it to some final conclusion that will minimize frustration to newcomers (and oldtimers!)
quote:
Originally posted by MartyE:

It stops all TMCC engines or anything else receiving its commands from the base. Including TPCs, modern ZWs, and Powermasters.


So just to get this clear in my head, if I had engines 26, 30 and 54 all running and I have engine 54 selected on the CAB-2. Suddenly engine 30 stops do to TMCC issue, I hit the emergency stop would 54 and 26 stop without me having to select 26?
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