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Discussion Boards => HO => Topic started by: SteamGene on July 14, 2007, 03:22:04 PM

Title: DCC acting up
Post by: SteamGene on July 14, 2007, 03:22:04 PM
I got DCC mostly installed on Thursday and it ran fine with the two locomotives previously reported.  Suddenly they wouldn't respond to the throttle.  I shut everything down, and Friday morning I turned the system back on, tried the locomotives, and they worked fine.  I added C&O H-5 1524 (USRA light Mallet) and it ran fine.  Then again, after several hours they refused to respond to the throttle.  Background sound - pumps, air leak, appliances turning on and off, etc, continued to work.  But nothing with the throttle.
I tried again this morning.  Track power on and sound was on, but no response to the throttle.  I tried another locomotive, VT&P T-4, Number 354 (USRA heavy Santa Fe) and it didn't respond either.  I'd called Tony's and got "It's something wrong with the locomotive."  I don't think so.  Not all four. 
Any idea?  I'm using Digitaxx with the DSC100 (?) command station and a DT400R throttle.
Gene
(BTW, wife went in not knowing I'd already been in and heard the locomotives simmering and got worried - or so she claimed.  ;D
Title: Re: DCC acting up
Post by: richG on July 14, 2007, 04:57:28 PM
I would put only "one" loco at a time on the track. Don't know if you did that. Also join the Yahoo Digitrax group. Over 7000 members. http://groups.yahoo.com/group/Digitrax/

Rich
Title: Re: DCC acting up
Post by: SteamGene on July 14, 2007, 05:11:50 PM
That's how I started.  But I can remove all four, or three, or try a new one.  I'll do that.  OTOH, the 400 now displays "Ra=00" which is a code I can't find anywhere.
Gene
Title: Re: DCC acting up
Post by: richG on July 14, 2007, 05:19:33 PM
I have the NCE Power Cab and I am not familiar with the Digitrax. Probably not any help.

Rich
Title: Re: DCC acting up
Post by: tomcat623 on July 14, 2007, 05:23:16 PM
Gene, check your engines at the power supply track section. I had the same problem. turned out it was hairline cracks in the soldered track joints
Title: Re: DCC acting up
Post by: tomcat623 on July 14, 2007, 05:27:08 PM
it seems that the cracks would open up after running a while, after being off for a while they would work again. Super close inspection revealed the problem.
Good luck, Tom
Title: Re: DCC acting up
Post by: SteamGene on July 14, 2007, 05:55:37 PM
Tom,
The problem with your idea is that each locomotive is on a different track.  It's hard to believe that four tracks lost current at the same time.  But I can check tracks for voltage.  OTOH, as i said, I'm still getting sound out of them - just not sound I can control like bells and whistles.
Gene
Title: Re: DCC acting up
Post by: tomcat623 on July 14, 2007, 06:00:40 PM
Sorry it didnt help, I sure hope its something simple and cheap to fix. Let us know what you find out. Good luck
Tom
Title: Re: DCC acting up
Post by: SteamGene on July 15, 2007, 02:04:43 PM
Well, they seem to be working again, with the possible exception of the BLI light Mike.  The USRA heavy Santa Fe also works.  I took them all off, put the heavy Mountain back on and BAM! sound and movment.  I think there are DCC gods with strange powers and desires.
Gene
Title: Re: DCC acting up
Post by: SteamGene on July 15, 2007, 05:37:53 PM
Confirmation - taking them all off the track and putting them on again solves the problem.  Now the question is "why?"  Also, the BLI light Mike seems dead.  I will have to check it.
Gene
Title: Re: DCC acting up
Post by: SteamGene on July 16, 2007, 08:59:21 AM
Hmm - B LI Mike came back to life, but now, even after taking every locomotive off the tracks, I have no control - sound, but no control. 
Where is the post by Nigel?
Gene
Title: Re: DCC acting up
Post by: Tim on July 16, 2007, 11:06:21 AM
Gene

You may have toreset the BLI to the as delivered settings.
That has been my experience with them.

The problems you have experienced with your system are not new
but are not well documented.

The problem is noise on the track buss, it can cause wacky operation
of the decoders, (usually temporary) and can sometimes cause a loco
to forget it's programming.

A good fix is to terminate the track buss (s) with a RC circuit as follows.

At the end of each buss pair , attach a 100 ohm 1w resistor in series with
a 0.01 ufd 100v ceramic capacitor, between the legs of the buss.

Noise can also occur on the control buss in extreme cases, (very long
runs).

The power buss is usually the guilty party.

My E-Mail is in my profile if you have more questions.

Tim Anders
Souderton, Pa

Title: Re: DCC acting up
Post by: SteamGene on July 16, 2007, 11:12:00 AM
Thanks, Tim.  I'll try that.  The longest run I have so far is for East Penninsula, which is probabl about fifty feet total for the buss wire.  I'm assuming that the length is the total length and not just the length that already has drops attached to it.
Gene
Title: Re: DCC acting up
Post by: jsmvmd on July 16, 2007, 11:14:46 AM
Dear Tim,

Terrific answer!  I will consider doing as you suggest when I take the plunge into DCC.

Not to waste your time, but have you any links comparing Digitrax, CVP, NCE, Dynamis, etc.  I do not have the opportunity to try these systems hands on, and it is making my choice very difficult.

Best Wishes,

Jack
Title: Re: DCC acting up
Post by: Tim on July 16, 2007, 12:37:18 PM
Gene

The noise filter goes at the very end of the buss.
If you have more than one buss put one at the end of each.

At 50ft run, you may want to consider adding a booster at about 25ft.
It depends on how heavy the load will be near the end of the buss run.

Jack

The Digitrax Zephyr and NCE powercab are directly comparible, as are the
Digitrax Super Chief and NCE Power Pro. The Digitrax systems are more
technically oriented, whereas  the NCE systems are more user friendly.

CVP has two systems, Easy DCC & RailCommand, Easy DCC is NMRA
compatible and can run any decoder as the above systems.
RailCommand requires it's own decoders.

MRC Prodigy is also worth concidering, but lacks expandability

The rest aren't worth looking at.

Tim Anders
Souderton, Pa
Title: Re: DCC acting up
Post by: SteamGene on July 16, 2007, 12:44:52 PM
I'm using Digitraxx entirely - other than decoders, of course.   Each penninsula will support, as a rule, three locomotives - two mainline and one branch/switcher.  Eventually all the locomotives will be sound equipted.  That will take awhile. 
I'm not sure why the DCC companies are having a PC/Mac war.   It would be nice if one could mix and match command stations/boosters/ throttles. 
Gene
Title: Re: DCC acting up
Post by: Tim on July 16, 2007, 01:28:37 PM
Gene

You can use NCE & Digitrax boosters together, the command stations
all use a different command protocal between the throttles and command
stations.  Each one is the best depending on your point of view.

Jack

I forgot to mention LENZ, their system 90 and system 100 are comparable to
the mid-size systems of digitrax & NCE.

Tim Anders
Souderton, Pa
Title: Re: DCC acting up
Post by: jsmvmd on July 16, 2007, 03:20:54 PM
Dear Tim & Hunt,

Thank you, both!

Best Wishes,

Jack
Title: Re: DCC acting up
Post by: SteamGene on July 16, 2007, 04:03:40 PM
Hunt, sorry.  I had to wait to answer the questions.  I'm still going through a lot of things and getting hit by different opinions. 
Gene
Title: Re: DCC acting up
Post by: Jim Banner on July 16, 2007, 11:41:01 PM
Gene, this is just a thought.  When you turn on your DSC100 using your DT400, does the power dot stay on steady or does it flash?  If it is flashing, it means you are in Stop Mode and have track power but no DCC signals being sent.  This should give you sounds but no motion.  See page 53 of your manual.

Another thought.  Your sound decoders probably have large capacitors on them or attached to them to allow them to work on "regular d.c." which is unfiltered, rectified a.c.  It is weren't for these capacitors, the sound system would hum on regular d.c.  On DCC these capacitors can appear as a short to the command station when first turned on.  Try setting the short circuit shutdown time to 1/2 second by closing OP switch 18 in your booster.  See pages 115 to 118 in your manual.

You probably won't have appreciable ringing (noise) on your track power bus unless it is over 30 feet long.  My longest is 50 feet and is as clean as a whistle when checked with an oscilloscope.  I use a DSC200 which is the same as your DSC100 except for a larger output.

The rA:00 on your DT400R is just telling you that it has detected a radio receiver and is operating on radio channel zero.  See page 98 of your manual.
Title: Re: DCC acting up
Post by: SteamGene on July 17, 2007, 07:52:40 AM
Thanks, Jim.  I'll check that out this morning.  I had a thought in the night.  The end of the East Penninsula buss is curled around a couple of risers as the track work is not finished yet.  Could that be a part of the problem?  I'm going to unwind that this morning and string it along  the benchwork to where it will go when the rest of the risers are attached and see if that solves the problem.
Gene