Big_Boy_4005 posted:

I've thought of poles, I'm not sure what kind of lateral reach the signal would have, ie how many tracks can one wire cover.

I just added this structure yesterday. It runs right down the middle of a trouble spot. It will be very easy to add a wire here. The trick with poles is keeping them out of the way, so they aren't getting snagged.

 

Before you do a lot of work, I would try a wire along the top of the wall on the right...just to see.

Now you're reading my mind Chuck. That wall is right down the middle of 6 parallel tracks. The foam bluff, yet to be built, will cover it perfectly. It will be a good test. See if one wire will reach all 6 tracks. Fingers crossed.

One ground wire covers quite a wide space as  rule.  It's likely that one wire sort of centered on the tracks will do the trick.

gunrunnerjohn posted:

One ground wire covers quite a wide space as  rule.  It's likely that one wire sort of centered on the tracks will do the trick.

Excellent John! One down about ten to go. I'll try to be creative about it.

Personally, I don't think the situation is as bleak as others would portray it.

Mike Reagans TMCC/ Legacy signal video  recommends running the ground wire along the tracks, between parallel tracks. Go to 12:40 on this video https://youtu.be/UQ-hiIvPxVs

Earlier in the video it discusses the signal interference of over and under trackage

I'm under the impression your chicken wire keeps the lower level from interfering with the upper, but it doesn't solve the parallel tracks ground plane issue.

I'm no expert, just "cobbling together" information I've gathered from other sources.

Love your layout.

Good Luck, John 

I new it was the base. Great find. And now you can get back to the layout! 

NYC,SUBWAY TRANSIT SIGNAL posted:

Love your layout.

Good Luck, John 

Thank you John. I do love the NYC subways. Last time we were there, we did some serious riding. What I'm modeling is Minnesota local.

Rick, I have those wires throughout both hidden yards, as well as along some of the mainline on the lower level. I need to revisit those, because some seem less effective than others.

I have seen Mike's video many times, just not recently. I think I've found that a wire placed higher rather than lower, works better. One of the things that that was supposed to combat was conflicting signals from parallel tracks of different lengths. I really don't have situations like that, because every section of the layout shares the same ground wire, so there is only a single signal on all parallel tracks. It seems like it's more about the antennas finding the airborne component, which is why the higher wires seem more effective.

I'll keep working on it.

Very glad you got the legacy base sorted out, Elliot.  This has really been a great thread with lots of knowledgable people sharing their experience and wisdom.  Thoroughly enjoyable to follow along.  I'm looking forward to seeing how the signal issues are solved.  

For clarification, you have chicken wire laid out under the plywood on the upper level, and that level is working without issue, but on the lower level, up to this point you have only the conduit of the 120VAC lines acting as a ground plane source?  I understand that an overhead wire is probably the best solution to provide the strongest signal, but have you tried perhaps stapling some chicken wire to the underside of the layout in the trouble areas? (or perhaps using spray glue and aluminum foil?) My brain is thinking if it works in one level, it may provide enough signal in others.  Then again, it may be that with six parallel tracks the track signal side will wash out the ground plane side with it radiating from below.  Again, just tossing out ideas to which more experienced folks may already know the answers.  

JGL

Nice job Elliot. Glad you got the main problem sorted

Nick

Thank you Nick. Patience and persistence are the words of the day. There were those who just said send it in. I'm glad I toughed it out a bit. If you look back on page 4, near the middle, that's where the diagnosis came together. After that, the surgery was easy. This has been a fun topic, getting a lot of people involved, and thinking out in the open.

This isn't the end of the story though. There's a lot more to be done to get everything running smoothly. I just ordered a cheap AM radio off eBay to do one of Dale's tests. Should be here next week. 

Thanks JGL. I was actually thinking about adding some ground plane material under there to see if it helped. The nice part about the upper deck was it was built in during construction. Retrofitting is a pain, because all the wires and Tortoises are in the way now. 

Have you ever seen a picture of the small helix? Best signal anywhere on the layout, because I lined it with foil, and built the ground plane in. The big helix was recently retrofitted with a single wire all the way up. It works pretty well too now.

Now that the legacy base is fixed, I think I'll change the topic title one last time, to something we can run with...

Adventures in TMCC & Legacy

RickO posted:

Mike Reagans TMCC/ Legacy signal video  recommends running the ground wire along the tracks, between parallel tracks. Go to 12:40 on this video https://youtu.be/UQ-hiIvPxVs

Earlier in the video it discusses the signal interference of over and under trackage

I'm under the impression your chicken wire keeps the lower level from interfering with the upper, but it doesn't solve the parallel tracks ground plane issue.

I'm no expert, just "cobbling together" information I've gathered from other sources.

 

RickO,

I learned in another thread where a club was losing signal in one curve, that the elevated wire is the more effective method. There were some notes from Jon Z., perhaps posted by NJ Hi-Railers in working out their signal issues. If I find that, I'll post the link.

One thing of note with a large layout.  If you have too much "antenna" area and get excessive coupling between the track signal and the ground signal, that could result in a lower amplitude signal from the base due to excessive loading.  I suspect if you measure the capacitance between the outside rail and the ground plane, you might be surprised how large a value it'll be.  Obviously, this measurement would be with the command base disconnected.

gunrunnerjohn posted:

One thing of note with a large layout.  If you have too much "antenna" area and get excessive coupling between the track signal and the ground signal, that could result in a lower amplitude signal from the base due to excessive loading.  I suspect if you measure the capacitance between the outside rail and the ground plane, you might be surprised how large a value it'll be.  Obviously, this measurement would be with the command base disconnected.

My exact thoughts this AM. First of all the use of the term "ground plane". It's just a wire (connected to the house ground wire), in the air, over the track the engine is running on. The use of a large surface area like the chicken wire or large area metal foil seems like, as GRJ points out, a large capacitance between the track and the in the air ground wire. Which would reduce the amplitude of the signal.

I have asked Elliot to disconnect some of the earth-ground mesh to see how much the signal amplitude increases so that we can better understand the loading effects.

I suspect that the chicken wire is so close to the upper track that the effective radiation downward from the mesh is weakened.  More testing to come....

Sounds like a plan Dale.  I'm sure you're on top of this, it'll be interesting to see what effect it has.

Big_Boy_4005 posted:

"Thank you Nick. Patience and persistence are the words of the day. There were those who just said send it in. I'm glad I toughed it out a bit. If you look back on page 4, near the middle, that's where the diagnosis came together. After that, the surgery was easy. This has been a fun topic, getting a lot of people involved, and thinking out in the open."

Now that the legacy base is fixed, I think I'll change the topic title one last time, to something we can run with...

Adventures in TMCC & Legacy

Curious, would this have been solved much sooner if a known good Legacy base was substituted since the TMCC base functioned? Nice layout and construction thread.

Elliott, I am very happy to hear you got it resolved. 

BobbyD posted:

Big_Boy_4005 posted:

"Thank you Nick. Patience and persistence are the words of the day. There were those who just said send it in. I'm glad I toughed it out a bit. If you look back on page 4, near the middle, that's where the diagnosis came together. After that, the surgery was easy. This has been a fun topic, getting a lot of people involved, and thinking out in the open."

Now that the legacy base is fixed, I think I'll change the topic title one last time, to something we can run with...

Adventures in TMCC & Legacy

Curious, would this have been solved much sooner if a known good Legacy base was substituted since the TMCC base functioned? Nice layout and construction thread.

While this makes sense and I do agree. Sometimes it's just not that easy. I have my Legacy set away for repair at the moment. My issue was LCS operations so different from Elliot's problem.  It could have been quickly diagnosed with a spare Legacy set. However I only know of around 6 Legacy sets in the whole UK! Arranging to borrow one would have been a bit tricky.

I guess I could spend $300 and have a spare sitting in a drawer. But I have a spare TMCC base for a backup. 

I would like to see a diagnostic utility built in to the LSU software. So you attach your base to the serial/USB lead and your PC and it automatically checks everything is within operating limits. Might need some sort of special lead so it could check the output on the terminal so it could diagnose an issue like Elliot had. 

Nick

Elliot,

Put a frame up high  with chicken wire in the middle of  Train Room..

That should help improve a better signal throughout the entire Train Room 

Your  have to hard-wire to the chicken wire. but i think you was doing that already.

Please let us know how you make out.

Good luck, John