Hello all DCS experts,

The National Capital Trackers will be experimenting with various modules and wiring configurations in an attempt to get a reliable DCS signal around the layout. We are soliciting any and all suggestions on what has proven to work for modular layouts, and what experiments we should take.

The modules are currently wired according to the Tinplate Tracker standards using 4-pin Jones (Cinch) plugs on a 4-wire bus loop.

Our initial experiments will be:
- test alternatives to connecting the TIU to the track - via lighted track lockons or via a track wiring harness.
- use aux power for signal injection or run power through the TIU.
- break the layout into blocks and run a star harness for power feed to the blocks.
- location of balancing lights.

Thanks in advance for any constructive input this forum can offer,

John

Hi John,

I would suggest you start with power going through the TIU to your existing buss. I assume you want more than 10 amps capacity, so try using two or more TIU channels and splitting the bus into two or more sections. Leave out buss jumpers and use insulating track pins on "bridge" sections so the channels are isolated. In fact, your best bet is to install a center rail insulating pin on one end of each "bridge" section on the entire layout. Doing this means that each module is a separate "block" with only one pair of wires to each isolated section of track.

For light bulbs, start with a #1445 or #1447 bulb on each TIU output.

Early reports on DCS seemed to indicate that modular layouts worked well unmodified. This might have been because of the strong and consistent wiring throughout the layout coupled with the possible effects of the connectors. Hard to say.

I'd recommend you set up a "base test" layout configuration first as you need a consistent layout size to make the comparisons. You'll also need to set the variable channels to fixed to handle the two mainlines. As a former Tinplate Tracker, I'm going for the minimum amount of feed sources.

Since Tracker modules feed from the buss, I'd use insulated pins between modules to cut feedback.

I'd start by separating the layout into two equal-sized blocks. From there, the first test would be feeding from the end of the block using one channel per mainline -- a Fixed1 and Variable1 for block A's mainlines and Fixed2 and Variable2 for block B's mainlines. Check the signals at that point to see what you get. Depending on the length of the blocks, you may or may not get signal degradatation or feedback.

Next, I'd add the light bulbs on the TIU outputs and try again.

The next step I'd try is using a pair of terminal blocks -- one for each mainline and feed each from a single fixed channel. Put a light bulb on each terminal block and check your signal strength again.

After getting good baselines, I'd try another layout configuration. You may end up having to split larger layouts into more block sections.

Good luck. Let us know the results.

John

I sent Steve an E-mail. I live near by and have attended meetings on occation.


The Trackers layout was at York and I believe was still running DCS. Carl installed it very early one and actualy had the TIU positive leg in series so they could run 30 amps through an output. It was the early over lay set up we used to talk about but I forgot the name.


From what I have hear most of the modular layouts have worked well on good orginal grid wiring. I think having the center pins pulled really helps in this case.

Jamie

quote:

Originally posted by CSX FAN:
John

I sent Steve an E-mail. I live near by and have attended meetings on occation.


The Trackers layout was at York and I believe was still running DCS. Carl installed it very early one and actualy had the TIU positive leg in series so they could run 30 amps through an output. It was the early over lay set up we used to talk about but I forgot the name.

From what I have hear most of the modular layouts have worked well on good orginal grid wiring. I think having the center pins pulled really helps in this case.


Jamie

Jamie:

What you describe sounds like "passive mode" where the track power DOES NOT go through the TIU, but rather the TIU is paralleled onto the power leads and an aux power input is used to power the TIU itself. That allows full (30-amp) current to go to the layout without frying the TIU while allowing the TIU digital signal to superimpose onto the track voltage. I've tried it that way and it does work with varying results (depends on the integrity of the layout wiring, of course.) The only thing you lose is the E-stop (aka Panic Button) option with the DCS remote.

I've tried "passive mode" I think it works providing you follow Barry's wiring suggestions. Paired wiring, terminal blocks, light bulbs etc.

If you expect 2 wires from the output of a tiu channel connected to the track to super impose the Dcs signal on the track something similar to a Tmcc command base it's not going to work very well. Just my 2 cents.

Tracker John, I think the first step is for use to all use the same brand of track. Not the giant mismatch of all the manufacturers. The second step is to make sure all track and track pins are tight and clean. We need to break the layout into insulated blocks (center rail only). I will be getting together with the other trackers on Saturday. Hope to see you there!

...keep the rails polished...

John,
Here is what the Lehigh Valley HiRailers use.


And in operation...


We have run successfully with up to a 24x52' layout using this configuration and standard 6 pin molex connectors. Nothing special, no breaks in the track. 8-10s all the way around, except near one turnout. (I suspect a bad solder joint.)

Any troubles we have had were due to a semi disorganized multi-operator environment, not the equipment. What is important is to get handhelds, TIU addresses and engine addresses organized BEFORE a show! Things go a whole LOT smoother! (If this sounds like the voice of experience...) I whole heartedly recommend a totally separate "add track" for anyone bringing an engine that is not already "correctly" added in a manner to account for multiple operators. I also recommend NOT using the main layout for adding engines during a show. All kinds of whacky stuff can and does occur.

Chris
LVHR

Chris
LVHR

The Standard Gauge Module Association would like to add DCS to our next display at the November 1st and 2nd Train Fair in Syracuse, New York. Our existing wiring scheme has a track hot, an accessory hot and a common ground for each of the three tracks. The resulting nine wire bus is connected to adjacent modules using nine pin Molex connectors. Currently we connect each track hot to one throttle of a MTH Z4000, its accessory hot to the second throttle and the ground to the ground post. (Each track and its associated accessory hot has its own Z4000 transformer, providing ten amps to each throttle.) This allows us to use sections of insulated outside rails grounded by passing wheel-sets to activate relays for signals and other accessories. The 12 gauge bus wires are connected to the rails at two points on each module. We measured the voltage drop at our last event, and found it to be 0.1 volt for each 100 feet of track length. Each track loop will be about 250 feet long at Train Fair, although this will probably be increased at future events.

DCS seems like the perfect way to allow the operation of multiple trains on each loop. Unfortunately, Standard gauge trains use a lot of power, and 10 amps would typically be enough for only two trains. Our idea would be to divide the track loops into power blocks, providing ten amps of power to each from a TUI. Any pointers that could be provided by this group would be greatly appreciated.

Some of my observations of DCS operations at NCT shows:

1. Sometimes it works great.

2. Sometimes it is extremely erratic with signal levels ranging from 10 to check track. Sometimes the problem areas are mobile and shift to another layout segment during efforts to achieve a better signal.

3. We have observed this many times:

quote:

using the main layout for adding engines during a show. All kinds of whacky stuff can and does occur.

4. Yards and turntables typically have degraded signals (but this is where we want the most reliable control of engines).

5. Passive mode is desirable for high-amp multi-train operation but signal levels are typically better when we run power through the TIU.

6. TIU channels may output different signal quality.

7. Using 100% tubular track does not assure good signals. Some shows with good signal levels are a mix of track types.

So, we want to build a "cookbook" approach to adding DCS to a modular layout and have confidence that, after spending a hectic 2 hours schlepping the gear and setting up the layout, we can power up and operate DCS engines without fussing for another two or more hours.

After considering Frank Maguire's discussion of signal transmission issues, we have challenges.

John

John, thanks for the link. Frank Maquire's description of the dcs operation is very helpful in understanding what is going on. Every post I read on this subject builds my understanding, so thanks to all. I still find it interesting how complex these trains are becoming. I hope this does not lead people to stay away from command control reading these posts. Joe P.

quote:

4. Yards and turntables typically have degraded signals (but this is where we want the most reliable control of engines).

Add tiu, Trying to run everything from one tiu is going to be difficult at best.
In my opinion "Super mode" is the answer, You can have up to 5 Tiu, that's 20 channels, Each channel has it's own signal generator.

Try using a tiu channel just for the turntable stalls.

John,

I am currently working towards a "cookbook" solution for us as well.

Two tries so far have yielded less that satisfactory results. But I plan to keep trying.

Here is a thread about changing the wiring, which of course led to a lot of DCS signal discussion.

http://ogaugerr.infopop.cc/eve/forums/a/tpc/f/57660482/m/3601053174/p/1

The above referenced signal transmission thread was also very useful.

Chris,

Is that a surge arrestor with the green lights?

Bill,
Yes. It's a 4 channal Frank Qualls special. Check the HiRailers Unlimited website. I have each track and the acc voltage protected.

The TIU is wired for pass through on the Red side only. The Black side (common)is tied together with a heavy brass bar on the output side, so there is only one wire feeding the common side of the layout. This way, you don't blow the fuses inside the TUI!

Wire is all 14ga stranded.

Chris
LVHR

The National Capital Trackers team of Steve and Matthew K. (L and N), Frank H., Watson M., Bill R. (Farmer Bill), Bill C., George T. (GET Tracking), and Regis H. spent a hot Saturday in a non-air conditioned hall experimenting with DCS using a simple rectangular modular layout configuration.

The good news is the team developed what promises to be our cookbook approach for achieving high DCS signal levels on a modular layout. Their report follows.

I want to congratulate the NCT team for a lot of hard work and persistence. Well done, guys!

I also want to thank this forum for an excellent technical discussion of DCS signals and suggestions on what to try in our experiments.

I hope that other modular clubs can try the NCT approach and confirm that it works for other layout configurations. This experiment did not include T-modules, yards, and turntables. However, NCT shows in the coming months will provide us an opportunity to determine if our approach succeeds for varied layout configurations.



National Capital Trackers
DCS Project
28 June 2008

The problems we have encountered with DCS include:
1. The TIU doesn't see any engines, or the engines do not see the DCS signal, causing Check Track or Engine not on Track.
2. Losing control of an engine as it navigates the layout
3. Can't add or delete engines
4. Can't make any modifications to engines once control is established. Smoke, sound, etc.
5. Erratic Track Signal, 0-1-2 or nothing

We decided the only way to address the problem was to build a test layout for the sole purpose of trouble shooting the problem with a goal of at least improving the Track Signal strength. Our modular club adheres to the Tin Plate Tracker standards for module construction. Two main loops of track for each module connected via steel track pins and a wiring harness using 4 pin Cinch plugs for connectors.

The layout we constructed was 18 feet x 32 feet in a rectangular configuration. This approximates a typical NCT layout. The track on the modules was also typical ranging from Lionel O gauge to Atlas, K-Line, and GarGraves. Several switches were also evident, the old Lionel variety.

The main troubleshooting tool will be the DCS remote using the Track Signal option to test signal strength around the layout.

A) The first step was to set up the layout just as we do at any typical show this meant connecting the Track Power directly to the Buss wiring harness via a pigtail connector (utilizing male and female Cinch plugs.) A single MTH Z4000 transformer was used connecting both main outputs. One for the outer loop and one for the inner loop. Track power was not routed through the TIU. The power for the TIU is provided by an auxiliary power supply with the two fixed outputs of the TIU connected via another pigtail harness in a similar manner. The Buss was continuous with lights placed across the posts of both fixed TIU outputs.


Results: Both loops were checked using the Track Signal option. The same engine, running at approximately 3-4 mph, was used on both the inner and outer loops. We were not disappointed. The strength of the Track Signal varied from nothing to 1-2. We duplicated the problem, now to fix it!


While the layout was being assembled we looked for any bent track or loose fitting track pins and repaired them. Once the first pass of Track Signal checks was completed we cleaned both loops of track using several Trackman 2000 track-cleaning cars, plus wiping the track with an isopropyl alcohol cleaning fluid. The track was dirty but retesting showed no visible improvement.

B) The second step was based on input from the OgaugeRR Forum. We kept the power and TIU configuration the same, but removed the module-to-module center track pins and replaced them with fiber pins essentially eliminating the mechanical track-to-track path for power and the DCS signal. The only electrical path being the wiring buss. We started by breaking the buss and adding modules one at a time testing the signal strength as we proceeded.

Results: Initially the signal looked good, 8 to 10's, but when more than 6 modules were added the signal deteriorated to 1-3's. We attempted to "tune" the layout with bulbs connected to the buss using specially built test Cinch Male and Female Connectors with a bulb across the white or outside power wire. This was tedious and time consuming but achieved acceptable signal strength. Moving the bulb from one end of a module to the other caused significant signal strength degradation. Although satisfactory we ruled this out, as each set up would require tuning and the time required would be prohibitive. It is also noted during the testing process we improved the signal strength on the GarGraves modules by burnishing the center rail. Readings improved from 1-4.

C) We entered the third step confident that we could break the layout into four sections and provided separate feeds in a star pattern for the DCS and power connections. The Z4000 and TIU connections remained the same, but with four parallel feeds. We terminated the buss again with light bulbs across the end of the respective four busses.

Results: Track Signal testing commenced, but with no improvement. The best Track Signal we managed was 1-3 or nothing. We all were a bit frustrated at this time. Our 5 + hour effort had nothing to show for it. A lunch break was in order!

D) During our break we discussed our T/S plan and the apparent lack of any significant progress. We expected at least some improvement. So we came up with a few modifications to our plan. We did away with the star pattern cabling, but left the fiber pins intact between the modules. The wiring Buss was reconnected normally, but at the halfway point around the layout the Buss was disconnected. The big change this time was disconnecting the Z4000 feed and routing the two main Z4000 outputs through the two fixed ports on the TIU. We also left the auxiliary power supply in place.

Results: Testing began and to our surprise we were seeing 6-8's around the entire outside loop. The next step was testing the inside loop and again 6-8 on every module. Could this be our breakthrough? At the Buss break we put light bulbs across each feed; we did this on both ends of the Buss cable. To our amazement we immediately saw steady 10's on each module, both inner and outer loops. Just to see if the bulb placement was critical we reconnected the Buss and made the break at 25% point from the TIU connection with no change. Still steady 10's. The process was repeated in the other direction with the same results. It looks like bulb placement is not significant, as long as it's at the wiring Buss break. We even added additional bulbs across both fixed TIU outputs with no apparent effect. These bulbs were removed. Armed with our success we added several additional engines and saw no degradation of the signal or operational problems. We added five18 inch passenger cars all with working light bulbs, again no degradation. We even added a car with a blinking EOT light without incident.

E) The next step was to check each of our TIU's in this working configuration. We had four TIU's for testing .Two were Rev I3/4.0, one was Rev H1/4.0 and the last one was Rev G/3.1.

Results: Surprisingly the software level made a definite difference. Each of the 4.0 boxes all returned 10's while the 3.1 level ranged from 2, 4,6,7,9 in the exact same hookup. The Virginia TIU was at 4.0 and the Maryland TIU was at 3.1.

F) We then reduced the size of the layout by 4 modules
resulting in an 18x24 configuration. Retesting did not show any changes.

Results: Still steady 10's on both loops.

The NCT DCS Wiring Diagram is posted in Photo Albums.

Conclusions: Isolating each module proved effective. The fiber pins between modules, center rails only, seemed to eliminate any degradation caused by track type or track pin connection. The fiber pins and breaking the wiring Buss simplified the wiring path for the DCS data signal by eliminating multiple paths. Adding the light bulbs at the both ends of the Buss showed a marked improvement in signal strength. The light bulbs used were #53 a 14.4v and 12v.

The biggest improvement came from routing the track power through the TIU. With our modular layout the auxiliary power supply alone was not as effective. By keeping the auxiliary supply connected, even when routing of track power through the TIU, we could be assured the TIU would stay powered up even if track power were turned off.

The biggest surprise was the difference in signal strength relative to the different software level of the TIU. The latest level of 4.0 makes a big difference. Along with this observation the level of the DCS remote is also important. The older remote software level works fine but with a noticeable delay in engine response. Level 4.0 in the remote and TIU had an immediate response.

Respectfully Submitted by the NCT DCS Project Team


**************

Thanks again to the NCT team and the forum for working to develop a DCS cookbook solution,

John

Congratulations to John and all the NCT team!

It's nice to see you're taking such a methodical approach and documenting your results. Your improvement in signal strength with V4.0 vs. V3.1 is similar to what I saw on one large layout I used during beta testing. Areas that were flaky with 7,8,9 turned into 10's.

If you're interested in trying another configuration of "passive mode," I'd suggest you get some heavy amperage inductors and insert them into each wire of the pigtail used between the buss and transformer(s). That will isolate the transformer windings from the DCS signal. I've tested this on two layouts now and the results have been positive. However, neither of these layouts was over 300 sq. feet.

Hi Dave,

I'd like to try that so we can run high amps for multiple trains. A couple of questions:

Why is an inductor needed to isolate transformer windings (an inductor) from the DCS signal?

Do you have a part number for the inductors or should I thread the 12g power feeds through a ferrite donut?

Thanks,
John

Hi John, Good stuff, I'm curious how many tiu are you using? 1 for six modules?

The var channels can also be set to fixed mode. I'm sure you already know.

The club uses a single TIU for show layouts driving two main lines. Typically both of the fixed channels are used. The total number of modules in the loop is rarely less than 20. The DCS team conducted their testing on a 16x32 layout which is 4 corners plus 16 straights.

We see variation in DCS signal strength across TIUs and channels.

FWIW, my personal TIU has the strongest DCS signal out of Variable 1 in passive mode.

Tracker John:

Glad things worked out. Your wiring diagram tends to validate a theory I've had about how DCS works. Your diagram is virtually identical to the old "Thin Net" Ethernet computer networking configuration -- terminators on each end with the "computer" taps in between. Now I'm curious to see how far a buss can be run without severe signal degredation. Congratulations on your success and I admire the approach you guys used in the testing.

Hi Matt,

The Thin Ethernet analogy has me running screaming with loathing. Those were NOT the good old days ,,, workstations would randomly loose connectivity depending on which group of nodes were posered up. We always carried 50 ohm resististors with us and had to install Ts to add resistance along the line. (Sounds a bit like DCS.) Aaaargh!

John

quote:

Originally posted by Tracker John:
Hi Matt,

The Thin Ethernet analogy has me running screaming with loathing. Those were NOT the good old days ,,, workstations would randomly loose connectivity depending on which group of nodes were posered up. We always carried 50 ohm resististors with us and had to install Ts to add resistance along the line. (Sounds a bit like DCS.) Aaaargh!

John

Absolutely correct. The issuea with Thin-Net were exactly the same -- signal reflection and packet collisions. It used to be really entertaining setting one up. You had to balance everything and make sure you didn't have too many workstations on any branch. I actually had to run a "branch to nowhere" with a terminator on the end to clean up an imbalance. Go figure. Glad it's gone. DCS in a train layout is fortunately a little more linear.

Hi John,

quote:

Why is an inductor needed to isolate transformer windings (an inductor) from the DCS signal?

Do you have a part number for the inductors or should I thread the 12g power feeds through a ferrite donut?

An inductor of suitable specs (at least 100µH in my testing) absorbs what ever DCS signal is back feeding down the wires and prevents it from interacting with the transformer's secondary windings. Exactly what for of interference the transformer creates, I don't know. But, using the inductors to effectively eliminate it from the data network seems to help. If you look inside a TIU there are several large inductors inside. I don't know, but I suspect they are there to perform this filtering task across each channel.

The donut might be a good idea. I haven't tried that, but it's worth a shot. I've been using these INDUCTORS from Mouser. They're not cheap, but you only need two for each 10 amp power supply. I'll be very interested in your results, especially if you try the donut.

Tracker John, It's always good to get together with members of the Trackers. Figuring out problems as a group on our own time sure was a lot less stressful than figuring them out during a show. With problems being resolved we can now show off the best features of the different manufactured locomotives that we run without any embarrassing glitches. Watson M. (NCT)

...keep the rails polished...

The Standard Gauge Module Association plans to add DCS and TMCC to its control system. Currently we connect three MTH Z4000 transformers to the 12 gauge buss wires that run under each module. Two drops from each end of the three tracks are attached to the buss wires of each module. Separate grounds are maintained for each of the three tracks. In addition there are three buss wires which are used to provide power for relays grounded to insulated outside rails. Nine pin Molex connectors are used to connect the buss wires at each end of the module.

If we divide the layout into power blocks so that additional power can be provided (we want to avoid "passive" mode), would we expect the best DCS signal by running "star" wiring to the center of each power block and connecting light bulbs to the disconnected Molex connectors at both ends? Do the "star" wires running from the TUI to the buss wires need to be in twisted pairs, and do they need to be the same length? Should steel track pins be replaced with insulating track pins so that each section of rail is electrically connected to its buss wire but not adjacent rails? Is here any problem with the buss wires not being in twisted pairs?

Dave,

Thanks for the part number. Before I order parts, I'll try the donuts (takeouts from junked power supplies so the inductance will be a SWAG), and I'll also try snap-on ferrite RFI filters from Radio Shack (trying to find a easy solution).

Ironhorse,

quote:

would we expect the best DCS signal by running "star" wiring to the center of each power block and connecting light bulbs to the disconnected Molex connectors at both ends?

The NCT team stopped testing when a single-legged star achieved signal strength of 10s. To address STD Gauge high amperage operation with power districts (more than a single leg on the star), I would suggest each leg of the star follow that pattern with balancing lights terminating the bus at each end of the district.

quote:

each section of rail is electrically connected to its buss wire but not adjacent rails?

Many NCT modules are built using 10" tubular straights. The NCT team installed fiber pins only on the bridge tracks connecting the modules.

quote:

Is here any problem with the buss wires not being in twisted pairs?

Our bus wires are 4-wire trailer wire harness, 4-wire 14 Gauge electrical cord, and bundles of single wires taped or wire tied together. No twisted pair. I would recommend that your power and ground be paired to maintain consistent capacitance.

When I rewired my yard modules to improve DCS signals, keeping the power and ground feeds paired up (vs. individual wires straying all over the underside of the modules) helped considerably.

John

This is the way we have 50 modules wired. It will be difficult to pair the hot and common wires for each track.


[/URL]

quote:

Any speculation as to how much of an impact isolating every center rail had vs just isolating at the "ends" where the lamps are?

I have tried that at 2 different shows where all three rails of both tracks and the bus was not connected. I did not give us any measurable improvement in track signal.

Steve

L and N,

I think I would like to try this with the steel pins in except between modules 1 and "N"

Bill

PS I really think this is a very important thread and should be sticky!!!

quote:

think I would like to try this with the steel pins in except between modules 1 and "N"

The purpose of the insulated pins is to create 1 hot and common drop per block
in the diagram each module is a block.

BillP,

I think we should set up with one tether wired 1 to n modules with steel pins and the other with insulating pins. And see if there is a difference. And add the inductors. (MTH supplies inductors as apart of the Steam Upgrade kits.)

Bill,

After rereading my post it isn't exactly clear. The experiment that was tried at a show was to hook up the modules in the normal fashion. Metal pins were installed in all three rails of each joint on each loop of track. The only place that had insulated pins was the farthest point (180 degrees out) from the transformer. At this particular point the buss was not connected as well. Magic light bulbs were added, this did not work for us. This was tried at least twice, as they say results may vary.

Steve

I'm hoping we can leave most of the steel track pins and all of the track feeder drops to the busses in place, and just disconnect the molex connectors and add insulating pins at the break between the power blocks (with a feed to the center of the power block and lamps at each end of the busses). That would be a lot easier! I should be able to set up a SGMA design 16x36 foot (22 module) three track loop in my garage for testing later in the summer. I'll let you know how it goes!

Kirk

Steve,

I see so having pins in was not good. In that case we will go with insulating pins.

In fact, because it is the center rail, I think we will likely simply omit pins on the center rails. As a bonus that should make setup more quick.



There is only thing that scares me here. We have no redundancy. Usually the track pins provide a redundant path for power. Also we would run 3 feeds total for more redundancy.

We will now find out if any solder joints to the center rails have gone bad, because they will cause a dead block.

Also we are totally beholden to the molex connectors to carry the power around the bus.


Frankly its got my spider sense tingling...

Tracker John,


In trial C) did you have the center rails pinned or insulated?


Thanks,
Bill

Hey Andy,

How about making up the inductor caps? 1 male and 1 female 6 pin molex connector.

The wiring for each would be

Pin 1 -> bulb socket -> pin 4
Pin 2 -> bulb socket -> pin 4
Pin 3 -> bulb socket -> pin 4
Pin 6 -> bulb socket -> pin 4

I think I read once here that 24v bulbs are the best????

Clearly they need resistance soldering!!!!

quote:

In fact, because it is the center rail, I think we will likely simply omit pins on the center rails. As a bonus that should make setup more quick.

Initially we were thinking the same thing. We had a couple of issues during the test.
The first problem was we had a module next to a corner module with a large gap. After several laps around an engine got stuck when the roller dropped into the gap.
The next issue were a few modules with track that touched adjoining track, the insulated pins made quick work of that.
Related to the one above some of our bridge track rails slide easily, it is felt with the prolonged running the rails could shift and then touch.

With the above scenarios the team felt that using the pins would be better than encountering the above problems or any other that may show up.

There are going to be some areas where we don't use pins, any module with differing track. There are no insulating transition pins.

quote:

In trial C) did you have the center rails pinned or insulated?

The center rails were insulated.

About the bulbs, 18 volt bulbs are reported to work better than 24 volt. For testing we used #53's #1445 & 1447 are reported to work well. From the start of testing we had bulbs at the outputs of the TIU, when we came up with the winning combination the bulbs were removed from the TIU outputs with no signal strength degradation.


Steve

BILL P, yes this should be sticky, I second that motion. The two sticky's up top seem to be dated? I would always like to see a post this helpful and relevant stay up there. I have several topics saved as favorites on my computer for reference. If it crashes again I'll be hurt,

Barry's from Rand F.
http://ogaugerr.infopop.cc/eve/forums/a/tpc/f/93360682/m/9771054174
Grousing
http://ogaugerr.infopop.cc/eve/forums/a/tpc/f/93360682/m/1511082964/p/1
DCS tips
http://www.toytrains1.com/DCS_Tips.htm
more dcs tips from ramond
http://www.rayman4449.dynip.com/DCS_Tips.htm
BillP transformer...
http://ogaugerr.infopop.cc/eve/forums/a/tpc/f/57660482/m/3601053174/p/1
John S: bulbs
http://ogaugerr.infopop.cc/eve/forums/a/tpc/f/57660482/...691068754#8691068754
and more assorted readings if you get bored. Thanks to everyone again, Joe

BillP,

I don't understand your request.

I will call you when I get home and you can explain--slowly for the technically challenged.

I still think that we should set up away from a show and work out all the gremlins. As Tracker John's group did.

Andy

This message has been edited. Last edited by: ctr,

ctr,

Can we do it in your basement?

If we had a place to setup outside of shows I would be there right now running!!!

quote:

I still think that we should set up away from a show and work out all the gremlins.

This was something that couldn't have been done at a show as the layout was taken apart and reassembled many times. We tried a couple of things before during shows but you really don't have time to do science.

One of our members was able to get his church hall for a Saturday just for the purpose of the experimenting.

Steve

Bill P;

In response to your questions:

"¢ We used about 20 modules

"¢ Voltage drop from the module receiving power from the Z4000/TIU and the far end of the layout (farthest from power) was only about 0.7 volts.

"¢ Our modules are all connected to each adjacent module by wiring harness using 4 pin Cinch plugs for connectors PLUS track connections. It is the isolation of the center rail by way of fiber pins that eliminated multiple feedback paths. So you must insulate each module to insure total isolation of the signal to prevent multiple feedback paths from occurring anywhere on the layout.

Also, if you decide to air gap the center pins as opposed to using the fiber pins on the center rails, make sure the center rails do not touch!

Take Care!

George,

Thanks! Very valuable information.

Dropping 0.7 volts over 10 modules is probably OK. Our layouts tend to be closer to 40 modules so I would estimate 1.4 volts lost at the "far" end.

Another question for NCT.

Since you will be fully dependent upon the drop from the center rail to the bus for power, do you have any an y special plans for fixing field emergencies?

I see a few possible problems that can crop up at a show:

1) The drop feed from the center rail to the bus goes bad. The symptom is a dead block of track 1 module long.

2) The bus connector goes bad. The symptom would be a string of dead module blocks "moving" toward the "far" end (eg where the bulbs are.) Also a bulb would be out.

Under normal wiring: 1) would likely go unnoticed as the center rail pins would carry the current. 2) would also likely go unnoticed because current would be free to travel in either direction of the bus. So if on side of the bus was bad current could still travel the other direction.

3) the feed is bad in which case an entire track is dead.

We normally have redundant feeds for that issue...

I don't find any of these insurmountable, but likely scenarios we all would need to be prepared for. Because we all know anything that can go wrong will go wrong once you are at a train show!!!!

Dear Forum Moderators,

This thread should be sticky at the top.

The two present sticky threads are a bit dated.

Bill,

We haven't made a formal plan for these kind of "what ifs". During our testing we used some bridges that have no buss or feeders also one of the modules in our test layout has the bus but it did not have feeders to the track. For these areas we just simply used metal pins on one side to make what was in effect a longer module. These longer modules still just had one feed so we did not see a loss in signal strength.

Hopefully we will not have issues where something goes bad (bus wiring)during the during the show. We usually do a pretty good job of checking these kind of things before the show opens. We do have an assortment of jumpers that can be used for bypassing bad bus wiring. The affected modules would have to use regular pins between them until they connected to a module with a working power feed.

Steve

Steve,

So for now you would wind up separating the module and inserting pins if you detect the problem before the show... Easy enough.

But what if the problem develops mid show? I don't think our group could realistically stop all mains, separate two modules and insert pins in the middle of a show. Especially once scenery is up etc...