TMCC signal and ERR-equipped diesel

I am a long way from an expert but I do have a well operating Legacy system on a layout with a lot of track. See if holding your hand near the side of the engine minimizes the headlight flickering in a signal dropout area. If so adding a small wire connected to earth ground along the track in the bad signal area will likely fix the problem. It can be hidden with ballast or placed under the track/roadbed.

Another choice is to completely insulate the metal shell from the engine chassis using insulating washers. The antenna could then be connected to the shell. Some ERR retrofits in S gauge are done this way. I have one of the Legacy Buffers that Gunrunnerjohn made. These will provide a strong low impedance output from the Legacy base but the wires alongside/under the track for signal transmission must be done first. These wires are sometimes called ground planes, which is somewhat inaccurate.

Thanks, Tom.  The 12 ga copper ground plane wires went in along every track on the layout, usually on both sides, a couple of years ago.  They are connected to a true earth ground rod in several feet of dirt outside the basement wall.  Hands near the unit don't seem to change the problem. It would be hard to insulate the whole metal body of this unit as you suggest (and I've read before, from others), so moving the antenna to a more advantageous location would be more practical if that might help.

Keep the thoughts coming, please!  My grandson extracted a promise that I would get the City of Denver running, as he's taken a major shine to the old girl.

Take the top off of the engine and lay  the antenna on top  of the engine to see if the ERR Commander works right.  You can also let the antenna just drag along the side of the engine.  I always test my new ERR installs with the engine shell off ( I have the antenna wire glued to the shell ready to go on after my testing and use a extra antenna wire for testing. If all goes well, I place the shell on top of the engine and test with the shell just setting  on top, If that goes well I bolt the shell on  the engine.)

Tried elevating loco several inches above rails with signals and attaching wires to track under it for power.  Now, still flickers, but hand next to unit does reduce the flicker to near-none.  Still responds only to part of commands given: horn, bell, diesel revs, but no motor action and shutdown command does not lead to "shutdown" sequence.

This would make me think moving the antenna higher is not the answer.  And makes me wonder if the board(s) are having problems, since another new Legacy/TMCC geep runs all the way around the same mainline like it was meant to do, responding to all commands.

I think you need to borrow a Lionel legacy engine and see how it responds around your layout. This would determine how much of the issue is the converted diesel and how much is the layout.

The only comment about the layout is connecting the ground plane to an earth rod rather than to the ground pin on the Legacy base power supply is known to cause reception problems on some layouts.

I saw your last post after I uploaded mine. Sounds like it is either the metal engine shell or a bad ERR board.

cnwdon posted:

Thanks, Tom.  The 12 ga copper ground plane wires went in along every track on the layout, usually on both sides, a couple of years ago.  They are connected to a true earth ground rod in several feet of dirt outside the basement wall.  Hands near the unit don't seem to change the problem. It would be hard to insulate the whole metal body of this unit as you suggest (and I've read before, from others), so moving the antenna to a more advantageous location would be more practical if that might help.

Keep the thoughts coming, please!  My grandson extracted a promise that I would get the City of Denver running, as he's taken a major shine to the old girl.

The "ground" wires should only be connected to the third wire ground connection in your house wiring. You can reach this point from pin #5 of the DB9 connector on the base. They should not be connected to a ground rod in the dirt. The third wire ground wires in the house are actually the antenna for transmitting the TMCC signal to the antennas in the engines. The power supply for the TMCC or Legacy base is where the signal is connected to the third pin in the house wiring. The gauge of the additional ground wire over the track doesn't have to be large. #20 or so is quite adequate. 

It is possible that your Legacy base has low output. That is not a rare occurrence. There is a thread on how to measure the signal out of the U terminal on your base using a diode, capacitor, and multimeter. I'll see if I can find a link to it.

Looks like 2 vdc is a typical reading using this setup?

AmFlyer posted:

I think you need to borrow a Lionel legacy engine and see how it responds around your layout. This would determine how much of the issue is the converted diesel and how much is the layout.

The only comment about the layout is connecting the ground plane to an earth rod rather than to the ground pin on the Legacy base power supply is known to cause reception problems on some layouts.

A Legacy geep recently received new, running on TMCC from same base, seems to behave completely correctly, so this does seem to be an issue with the City of Denver conversion.

Puzzled about the ground rod versus house panel ground (ground pin of grounded outlet or equivalent ground bar at the electrical panel) versus base ground contact question.  At one time, true earth ground was the accepted wisdom as I recall.  Would like to learn more about that and reasoning behind choices.

cjack posted:

Looks like 2 vdc is a typical reading using this setup?

Thanks, understood, except don't understand value "D1 = 1N400x": what peak inverse voltage or other rating is needed for the diode?  50v or so PIV would seem to make sense, but do not know what the inverse voltage would be for that circuit for sure.

If this is a metal shell antenna is blocked and you must insulate shell from chassis and use it as the antenna.  Or put it outside the shell.

Swap the R4LC.  It may be the issue.  This is like troubleshooting any TMCC engine.  G

cnwdon posted:

cjack posted:

Looks like 2 vdc is a typical reading using this setup?

Thanks, understood, except don't understand value "D1 = 1N400x": what peak inverse voltage or other rating is needed for the diode?  50v or so PIV would seem to make sense, but do not know what the inverse voltage would be for that circuit for sure.

I use 1N4003 diodes, I think they are 1 amp, 200 piv. Good for most things on trains.

cnwdon posted:

AmFlyer posted:

I think you need to borrow a Lionel legacy engine and see how it responds around your layout. This would determine how much of the issue is the converted diesel and how much is the layout.

The only comment about the layout is connecting the ground plane to an earth rod rather than to the ground pin on the Legacy base power supply is known to cause reception problems on some layouts.

A Legacy geep recently received new, running on TMCC from same base, seems to behave completely correctly, so this does seem to be an issue with the City of Denver conversion.

Puzzled about the ground rod versus house panel ground (ground pin of grounded outlet or equivalent ground bar at the electrical panel) versus base ground contact question.  At one time, true earth ground was the accepted wisdom as I recall.  Would like to learn more about that and reasoning behind choices.

Grounding the third wire anywhere but at the house panel is against code. But anyway, for the purpose of the TMCC, the idea is to provide more third wire above the engines. I think the word ground caused a lot of confusion. The third wire is grounded, but only at the panel. The base introduces the 455KHz to that wire in the house wiring and it behaves as the antenna in the walls and ceiling to transmit to the engines. That's all there is to it.

cnwdon posted:

The 12 ga copper ground plane wires went in along every track on the layout, usually on both sides, a couple of years ago.  They are connected to a true earth ground rod in several feet of dirt outside the basement wall. 

This really is the wrong way to add a ground plane.  I see a couple of issues.

#1, the earth ground wires should NOT be right next to the track, they should be inches away, and preferably above the rails.  The locomotives respond to the signal differential between the outside rails and the earth ground.  Having them close to the outside rails is actually likely to reduce the signal levels and not enhance them.  The idea of the earth ground wiring is to enhance the signal to the antenna of the locomotive, these are usually near the top of the locomotives.

#2, the earth ground should always come from one point, that being the same outlet as the command base is connected to.  It's permissible to connect directly to pin-5 of the serial connector or the outside barrel of the command base power brick as well.

gunrunnerjohn posted:

cnwdon posted:

The 12 ga copper ground plane wires went in along every track on the layout, usually on both sides, a couple of years ago.  They are connected to a true earth ground rod in several feet of dirt outside the basement wall. 

This really is the wrong way to add a ground plane.  I see a couple of issues.

#1, the earth ground wires should NOT be right next to the track, they should be inches away, and preferably above the rails.  The locomotives respond to the signal differential between the outside rails and the earth ground.  Having them close to the outside rails is actually likely to reduce the signal levels and not enhance them.  The idea of the earth ground wiring is to enhance the signal to the antenna of the locomotive, these are usually near the top of the locomotives.

#2, the earth ground should always come from one point, that being the same outlet as the command base is connected to.  It's permissible to connect directly to pin-5 of the serial connector or the outside barrel of the command base power brick as well.

Ground wires are to the side of the ballast in most cases, so probably 1-1/2" away from the outside rail typically.  Difficult to change that in my case, too many hundreds of feet of track involved overall, and rarely a place where overhead placement could be made cosmetically acceptable.

I now hear the principle that the ground plane wires "send" the signal to the house ground wiring via the same outlet that powers the base, so I'll move the connection from the ground rod to a tie from the nearest ground wire point to the ground at that outlet. 

I still suspect I need to do something with the antenna on the City of Denver.  Is there a fraction of signal wavelength principle involved in the length of the ERRCo antenna wire?  Could that be doubled or quadrupled, say, to extend the wire and make the antenna into a train radio/phone antenna on top of one of the coaches, away from the heavy locomotive castings?  Wondering if loco base (or roof, too) casting is a load of some sort (capacitive?) on the signal, that could be reduced this way.  Out of my depth in the radio theory here.

cjack posted:

Looks like 2 vdc is a typical reading using this setup?

Good question, what would the DC voltage range be for a strong signal?

Steve

Read this thread on the TMCC signal strength using various measuring methods...

 https://ogrforum.com/...rack-signal-strength

Since the wavelength of 455khz is 656.979 meters or around 2155 feet, don't worry about fractional wavelength computations.  Just use the biggest antenna you can fit in.

cnwdon posted:

gunrunnerjohn posted:

cnwdon posted:

The 12 ga copper ground plane wires went in along every track on the layout, usually on both sides, a couple of years ago.  They are connected to a true earth ground rod in several feet of dirt outside the basement wall. 

This really is the wrong way to add a ground plane.  I see a couple of issues.

#1, the earth ground wires should NOT be right next to the track, they should be inches away, and preferably above the rails.  The locomotives respond to the signal differential between the outside rails and the earth ground.  Having them close to the outside rails is actually likely to reduce the signal levels and not enhance them.  The idea of the earth ground wiring is to enhance the signal to the antenna of the locomotive, these are usually near the top of the locomotives.

#2, the earth ground should always come from one point, that being the same outlet as the command base is connected to.  It's permissible to connect directly to pin-5 of the serial connector or the outside barrel of the command base power brick as well.

Ground wires are to the side of the ballast in most cases, so probably 1-1/2" away from the outside rail typically.  Difficult to change that in my case, too many hundreds of feet of track involved overall, and rarely a place where overhead placement could be made cosmetically acceptable.

I now hear the principle that the ground plane wires "send" the signal to the house ground wiring via the same outlet that powers the base, so I'll move the connection from the ground rod to a tie from the nearest ground wire point to the ground at that outlet. 

I still suspect I need to do something with the antenna on the City of Denver.  Is there a fraction of signal wavelength principle involved in the length of the ERRCo antenna wire?  Could that be doubled or quadrupled, say, to extend the wire and make the antenna into a train radio/phone antenna on top of one of the coaches, away from the heavy locomotive castings?  Wondering if loco base (or roof, too) casting is a load of some sort (capacitive?) on the signal, that could be reduced this way.  Out of my depth in the radio theory here.

The wavelength is over 2 thousand feet. Which also flies in the face of much of Lionel's video about timing differences between lengths of track on the layout.

cjack posted:

Read this thread on the TMCC signal strength using various measuring methods...

 https://ogrforum.com/...rack-signal-strength

Chuck, thanks for the link, very informative.

Steve

AmFlyer posted:

I saw your last post after I uploaded mine. Sounds like it is either the metal engine shell or a bad ERR board.

AmFlyer: Missed your post in the exchange, sorry.  Thanks.  Antenna is on outside of shell on the bottom, to clarify, with some electrical tape between it and the shell and then covered with another layer of tape.  Metal is pretty thick there, moreso than say a die cast steam tender shell where the antenna might be in a similar situation, so perhaps that is a problem for the signal (capacitance load??).  Anyway, will follow Keith Johnson (CBS072)'s suggestion and temporarily put antenna further "outside", on spacers above train, and see how headlight flicker and control response changes.  If not enough will try a longer 20 gauge antenna wire in the same way, along top of train, insulated.

I have a spare AC Commander board purchased recently from 3rd Rail folks (for planned 2nd B unit), so can try swapping board if all else fails.

Should mention present installation is combined A and B units, so board is running 2 open frame (prewar-style) motors.  Amp draw is only about 2 amps total, so don't think load is a problem.

Thanks again, Don

GGG posted:

If this is a metal shell antenna is blocked and you must insulate shell from chassis and use it as the antenna.  Or put it outside the shell.

Swap the R4LC.  It may be the issue.  This is like troubleshooting any TMCC engine.  G

George, missed post in exhange, late reply.  Antenna is insulated by strip of electrical tape and covered by another layer, OUTSIDE on bottom of shell, now.  Just replied to AmFlyer with other details of next testing plans.  The R4LC is the AC Commander board, yes?  Or is it a component board (radio) that is just part of the AC Commander larger board?  Have a brand new spare of the latter.

Thank you for the suggestions

Don

CBS072 posted:

Take the top off of the engine and lay  the antenna on top  of the engine to see if the ERR Commander works right.  You can also let the antenna just drag along the side of the engine.  I always test my new ERR installs with the engine shell off ( I have the antenna wire glued to the shell ready to go on after my testing and use a extra antenna wire for testing. If all goes well, I place the shell on top of the engine and test with the shell just setting  on top, If that goes well I bolt the shell on  the engine.)

Keith, missed your reply in chain, so late reply.  Will try your suggestions, and include trial of longer 20 ga antenna wire over top of trailing cars if existing short one not working well during trial (a train phone antenna atop the dining car wouldn't look out of place, if "longer" is better.)  Saw suggestion elsewhere that, with ~2000 foot wavelength for signal, longer antenna could not hurt and might help.)

Thank you, Don

cjack posted:

Read this thread on the TMCC signal strength using various measuring methods...

 https://ogrforum.com/...rack-signal-strength

Chuck, thanks for this.  I read the thread and emailed Dale Manquen today to ask if his signal strength testing device/meter is still available.

Don

I regret to say that Dale passed away last year. A true loss to his family, friends and the hobby.

Gunrunnerjohn completed the Buffer but does not make signal strength meters. In any event it sounds like you have a problem unique to this engine since other Legacy engines run fine on the layout.

Oh Don, I regret to inform you that Dale passed away a couple years ago.

The meter in question is just a way of measuring base output. There is also a meter for measuring signal strength around your layout, so you can spot check different problem areas. You can make your own one of these using an R2LC and the output from pin 13 as discussed in the topic linked by Chuck. 

I built one of these a few years ago from plans posted in this topic.

gunrunnerjohn posted:

Since the wavelength of 455khz is 656.979 meters or around 2155 feet, don't worry about fractional wavelength computations.  Just use the biggest antenna you can fit in.

GRJ: In another thread, I see mention that you offer (offered?) a TMCC or Legacy signal booster in kit form?  If Dale is not offering his device now, can you supply your kit (and is it for TMCC, Legacy, or both?)

Thanks, Don

Don, first off, the antenna taped to the tinplate is probably not going to yield the best signal strength, even a separation of around 1/8" is far better.  The capacitive coupling decreases as per the square of the distance between the two conductors.

I sold out of the TMCC buffer kits, but I did order a few sets of parts because I had some blank PCB's left, so in about a week I will have all the parts to build a few more.  After I get a chance to assemble the kits again, I'll post them.

I read in your post that your Legacy engine runs fine around the layout while the converted engine has problems in several locations. I had similar problems on my layout, one Legacy locomotive would be fine everywhere but another of the same type of Legacy locomotive had problems around the layout. The thing that solved the problem was first adding the ground plane, which improved performance greatly. I then added the signal booster that initially worked up by Dale M and built by gunrunnerjohn. I now have no signal problems, none of my engines Legacy or TMCC conversions lose the signal.

Ray

If your layout work fine with all your engines, except one.  You can certainly chase improving your layout, but usually the faulty engine is the problem.  Receiver on the R2LC/R4LC can go bad and have sensitivity issues.   Upgraded metal shell engine can have antenna get grounded, or have poor antenna location.

Take the shell off, run the basic antenna in the kit and test the engine . IF it runs fine, you need to get a better antenna location. Typically you insulate shell from chassis with Kapton tape, nylon washers and screws.  If still not right, swap R2LC and retest.  G 

George: Thanks for latest suggestions.  I have a list of "do's", will try one at a time and record results.  Believe I have a spare R2LC bought in error a while back, luckily. Don

All: Here is the first list of results.  Thanks to all of you, I've just been through "Legacy/TMCC" 401, the course I missed in college!

1. Changed the connection point for the ground plane wires from true earth ground to the ground terminal at the 110v outlet where the bases get their power.

WOW !!!  Few theories turn out to be so right, so fast.  The City of Denver's headlight flicker was almost completely undetectable, and I had control of all functions all the way around the 110 feet of mainline with just a couple of weak spots farthest from the base, and with layers of physical obstruction (plywood table top and backdrop, center curtain wall in basement.  Nearly "cured."  And this with antenna still taped to bottom of loco's cast underbelly.

2. Moved the antenna to a rooftop "radio antenna" location and lengthened it in the process: soldered about 9 in of 22ga solid copper wire to the end of the existing ERRCo antenna wire, enclosed it in slender styrene tubing I have on hand, mounted in a couple of improvised stanchions made from crimp loop connectors reshaped so they do the job.  Another major improvement in response to control signals.  Now have good control of speed and all other functions at all points around the mainline.  Photo included here.  A bit more dressing up with some additional and prettier stanchions, and some paint close to UP prewar streamliner "Leaf Brown", and it will look more like a train radio antenna.

3. Made a signal meter circuit with on-hand 47Kohm resistor and 1N4004 diode (PIV 400v instead of 1N4003's PIV 200v, otherwise same ratings).  With my Klein Tools electrician's meter, signal readings from bases as follows:

My old TMCC base: With no connection to track, 1.7 volts.  With connection to track in place, 1.2 volts

Legacy base: No track connection, 2.1 volts.  With track connection in place, 1.54 volts

Not yet tried: (1) Legacy 1L base/remote to put in service next, to try and also measure signal output.  And (2) the TAS signal booster, with my old postwar ZW for power instead of the twitchy ZW-C (separate thread!)  Do have some 0.1 mfd capacitors on hand, so I can make more boosters for additional mainline circuits if needed.  Doubt I would need except for the 3 long mains that have the greatest distance and obstructions to base signals.

Comments wanted--thanks, all, Don

Don, you do great work! That engine looks really nice.

This is one more example of how much the Legacy system dislikes 2 separate ground locations. Regarding your voltage measurements, I have one of GRJ’s Buffers. It has DC voltage measurement terminals at the input and output. I measure 2.7V at the input from the Legacy base and 8.05V at the output to the track. These are both with a little more than 700’ of track connected. I am not certain these are directly comparable to your measurements but they should be close. I need to reduce the gain from the Buffer to about 5V to get the sensor tracks to work.

If GRJ makes a few more of these available I recommend you buy one.

cnwdon posted:

All: Here is the first list of results.  Thanks to all of you, I've just been through "Legacy/TMCC" 401, the course I missed in college!

1. Changed the connection point for the ground plane wires from true earth ground to the ground terminal at the 110v outlet where the bases get their power.

WOW !!!  Few theories turn out to be so right, so fast.  The City of Denver's headlight flicker was almost completely undetectable, and I had control of all functions all the way around the 110 feet of mainline with just a couple of weak spots farthest from the base, and with layers of physical obstruction (plywood table top and backdrop, center curtain wall in basement.  Nearly "cured."  And this with antenna still taped to bottom of loco's cast underbelly.

Funny thing, you connect it right and things start working!

cnwdon posted:

2. Moved the antenna to a rooftop "radio antenna" location and lengthened it in the process: soldered about 9 in of 22ga solid copper wire to the end of the existing ERRCo antenna wire, enclosed it in slender styrene tubing I have on hand, mounted in a couple of improvised stanchions made from crimp loop connectors reshaped so they do the job.  Another major improvement in response to control signals.  Now have good control of speed and all other functions at all points around the mainline.  Photo included here.  A bit more dressing up with some additional and prettier stanchions, and some paint close to UP prewar streamliner "Leaf Brown", and it will look more like a train radio antenna.

Yep, major improvement in antenna location, get it away from the frame and magic things happen.   Steamer antennas are less than 1/4" away from the metal shell, but that little bit of spacing does wonders over being right next to the frame.

AmFlyer posted:

Don, you do great work! That engine looks really nice.

This is one more example of how much the Legacy system dislikes 2 separate ground locations. Regarding your voltage measurements, I have one of GRJ’s Buffers. It has DC voltage measurement terminals at the input and output. I measure 2.7V at the input from the Legacy base and 8.05V at the output to the track. These are both with a little more than 700’ of track connected. I am not certain these are directly comparable to your measurements but they should be close. I need to reduce the gain from the Buffer to about 5V to get the sensor tracks to work.

If GRJ makes a few more of these available I recommend you buy one.

It's not a question of separate ground locations, it's the case connecting the additional ground wires at all. It's not a grounded wire that helps, it's a wire connected to the third wire ground wires in the house wiring. Connecting to a grounded rod is essentially totally not connected to the house wire grounded at the service panel.

I like the GRJ buffer as well. Of course the dc voltage readings using different circuits will yield somewhat different results. Don's readings are in the ball park as are yours.

As to the antenna close to the boiler or a bit away, the issue is capacitance which will short out the signal to some extent. The formula for capacitance is EA/d, that is a constant E, times the Area of the wire, divided by the distance d between the wire and the boiler. As you can see, a distance of .25 inches is a much bigger number than say .01 inches and consequently the capacitance is much greater and a much greater short circuit from the increased capacitance.

That's why even a small separation from the frame/metal shell makes a huge difference.  Any significant capacitive coupling between the track signal (locomotive frame) and the antenna really kills the reception of the TMCC signal.  We're usually talking about micro-volts here.

In reference to separate grounds, several layouts have solve significant issues with grounding by using a common connection point for the earth ground, it's not just me theorizing.

After the voltage measurements, went back to run the train while both Legacy and TMCC bases were powered and connected to track (without the interface cable connected for running TMCC using Legacy remote).  Headlight flicker and TMCC signal failure were baaaaaack!  (Loco started up "conventional" as though no command signal was present at all.)  Disconnected Legacy base from track and all was well again.  Guess they don't play well together?

AmFlyer posted:

Don, you do great work! That engine looks really nice.

This is one more example of how much the Legacy system dislikes 2 separate ground locations. Regarding your voltage measurements, I have one of GRJ’s Buffers. It has DC voltage measurement terminals at the input and output. I measure 2.7V at the input from the Legacy base and 8.05V at the output to the track. These are both with a little more than 700’ of track connected. I am not certain these are directly comparable to your measurements but they should be close. I need to reduce the gain from the Buffer to about 5V to get the sensor tracks to work.

If GRJ makes a few more of these available I recommend you buy one.

Yes, will watch for John to announce those guys, agree it would simplify my life. I note your Sensor Tracks comment, and will remember that when I finally start using those--too much gain is not "better". Don

How could I forget?  I had to call grandson Sam and ask him which train he thought I was running, and toot the horn for him over the phone!