Analog Operation

[CTValleyRR]

OK, assume I know next to nothing about DCC and you won't be far off.

I want to get into DCC, but for economic reasons I can't afford to buy a DCC system and a bunch of decoders all at once.  What I DON'T want to do is take my layout out of service until I can get a full- scale DCC system installed.

After reading a lot -- here, elsewhere online, and actual, old fashioned paper -- I have arrived at several conclusions.  Maybe impressions would be a better word.

1) Most DCC systems will not run a loco without a decoder in it, so if I bought the system first and then bought and installed decoders, I would be limited to running those locos with a decoder in them, and locos "returning to service" would be limited to how fast time and money allowed me to install decoders in my locos.

2) Many decoders (all?) will operate in "analog mode", so that if you put it on a DC-powered track, it will operate normally, provided one of the CV's (29?) is set to "analog operation on" (or something like that).

Now, it would seem -- if the above is correct -- that I should start gradually purchasing decoders and installing them, and then spring for the DCC system once I have a few decoders installed.  BUT (there's always a but, isn't there?):

a) is there a risk of shorting out a decoder by giving it too much juice on a DC track?

b) are DCC locos operating on DC tracks prone to operating anomolies?

c) if I don't have a DCC system, I can't program a decoder, so is there a way to fix operating issues (like the default value of the analog CV is "off") short of ripping out the decoder again?

Any insights would be greatly appreciated.

[jeffrey-wimberly]

davidmbedard

 If you go with Digitrax, you can absolutley run one Analogue loco. 

Good decoders (NCE SRJ13s) can be had for cheap when bought in 10s.

David B

With my Digitrax Zephyr I can run 1 analog loco at the same time as my DCC locos or run 2 or more analog locos using the blocking switches on my layout. Only problem is all the analog locos will run at the same speed and in the same direction. That's what's so cool about DCC. I can have several trains running at once, in different directions at different speeds.

[maxman]

CTValleyRR

2) Many decoders (all?) will operate in "analog mode", so that if you put it on a DC-powered track, it will operate normally

I don't know if "all" is correct, but many decoders are supposed to run in analog mode.  Unfortunately, at the club where I belong we have had difficulty trying to do this.  I think it might have something to do with the type of DC controller one has, or maybe more specifically the quality of the DC power output.  The DC controllers at the club are a handheld type from Dallee.  Some of the more electrically astute members believe that there is some backgroud AC mixed in with the throttle DC output.  This seems to "confuse" some of the decoders.  As power is initially applied, the engines will start moving in one direction, and then suddenly reverse themselves.  This causes havoc with a double-headed unit when one engine tries to move in opposite direction to the other.  Another issue with the sudden reversal is the slack being run in and out of a train, causing a derailment problem.

You may not have this problem.  Might I suggest if you want to try this is to install one decoder in an engine and try running it around and experimenting a bit.

[CTValleyRR]

davidmbedard

 If you go with Digitrax, you can absolutley run one Analogue loco. 

Good decoders (NCE SRJ13s) can be had for cheap when bought in 10s.

David B

Don't forget, I'm a DC guy.  One loco, one direction, one speed.... that's what I get right now.  But you're saying that with a Digitrax, it will run ONE non-decoder equipped loco, right?  So, in theory, having a Digitrax unit with no decoder-equipped locos would be no different than DC.

The Walthers website shows an NCE D13SRJ -- same thing?.  $75 for a 4 pack (yes, I'd shop around for a better price before buying) would be about the maximum I would want to spend at any one time.  $150 for a 10 pack is almost a budget buster -- I sure wouldn't be doing that and a DCC system in the same month.

 

[mfm37]

CTValleyRR

 But you're saying that with a Digitrax, it will run ONE non-decoder equipped loco, right?  So, in theory, having a Digitrax unit with no decoder-equipped locos would be no different than DC.

  

 Having a DCC system with no decoder-equipped locos would be pointless. With one DCC engine and one DC engine you could run them both in the same block with no switches. Even have a cornfield meet.

CTValleyRR

The Walthers website shows an NCE D13SRJ -- same thing?.  $75 for a 4 pack (yes, I'd shop around for a better price before buying) would be about the maximum I would want to spend at any one time.  $150 for a 10 pack is almost a budget buster -- I sure wouldn't be doing that and a DCC system in the same month.

I wouldn't purchase decoders from Walthers unless I was into spending MSRP. Places like Tony's Train Exchange http://www.tonystrains.com/ , Litchfield Station http://www.litchfieldstation.com/lobby/index.htm,  have discounted prices even for single items. There are many others with comparable prices.

There can be some issues running Decoder equipped locos on analog DC.

First, their slow speed operation is non-existant. That's because the voltage has to overcome the drop through the decoder's components before you get any movement.

Second, you need "clean" DC. Analog Packs with pulse power will not work until the speed is turned way up and the pulses smooth out . That's because the DCC signal is a pulse. So at lower speeds the decoder sees pulses but since their message is not addressed to that decoder, it just sits there as it was designed to do. Finally; when  the pulses smooth out, the decoder sees it as DC and responds.

Most (if not all)  decoders come new with CV29 set to run on analog. You would normally need a DCC system to turn that ability off.

Martin Myers

 

[cudaken]

 My bench had two main lines that where blocked for DC. A line was ran with one DC controller and B with a different one. I bought a simple Bachmann E-Z command and used it on the B line and A was still DCC. It was a simple way to get started.

 Many DCC system will run a DC engine's, Bachmann E-Z is one of them. Down side is most DC engines make a nasty humming sound when ran on DCC.

 Digitrax DH 123 and 163 are fine on DCC. I still clean my wheels with a MRC unit. As noted, long as the has not been changed so it will not.

          Cuda Ken

[MisterBeasley]

Buy the box.  Then you'll have something to think outside of.

If you have a very simple one-block, one-throttle DC layout, it is very easy to add a double-pole, double-throw (DPDT) toggle switch which will let you go back and forth between running DC and running DCC.  Connect your track wires to the center posts, the DC power to one side, and the DCC power to the other.  Then, you can continue to run your DC engines on DC, and switch over to DCC as you add decoders to your fleet.

 Most (but not all) DCC system support a "programming track."  This is a separate set of outputs used for programming engines with decoders.  One big advantage of this is the ability to pre-test your decoder wiring using very low voltage on the programming track before you put the engine on your main line and give it full power.  If you've wired the decoder correctly, you'll be able to program it.  If you can't program it, though, then it's wired wrong.  Because you've only used a low test voltage, though, you will have done no damage.  If you put an incorrectly wired decoder on the main line, you stand a pretty good chance of "smoking" the decoder.  Since you're on a budget, you don't want to be turning these things into paperweights.  For one thing, they're light, and won't hold down much paper at all.