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BLI 2-8-0 Consolidation - says DC and DCC, but is it really?

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Posted by crossthedog on Sunday, August 22, 2021 11:49 AM

Can someone please change the title of this thread to correct "Consolidated" to "Consolidation"? How embarrassing. I know someone can do it because my post titles have been edited by others before. Please and thank you.

-Matt

UPDATE: Never mind, I figured it out. -mdf

 

Returning to model railroading after 40 years and taking unconscionable liberties with the SP&S, Northern Pacific and Great Northern roads in the '40s and '50s.

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Posted by crossthedog on Sunday, August 22, 2021 11:41 AM

Before this becomes completely about something else (too late, right), I just thought I'd say thanks everyone for the information about this... and even your personal opinions on this. I don't think I'll have a compelling reason to run my new DCC loco on the DC system and thanks to this thread I can see compelling reasons NOT to.

When I'm in a sound mood I'll be able to run my Consolidation as the mainline power (freight or passenger), and drop cuts of cars for the RS-3 to come fetch off the siding, build into trains in the yard, and run up the branch to deliver in Priest River. Otherwise, I'll run my DC locos and I have ten power blocks to play with. Tickety-boo.

@Sheldon, I'm glad you said you find sound annoying after a while. I have experienced the same thing and felt guilty about it. I like the sounds, but it does start to get on my nerves and I thought maybe there was something wrong with me.

JDawg
I think we have the same dreams. That engine is like a temptress. Buy me sir, I can be all yours for less than you think. Still talking about the engine by the way.

Ha ha, yes JDawg. Well said.

-Matt

Returning to model railroading after 40 years and taking unconscionable liberties with the SP&S, Northern Pacific and Great Northern roads in the '40s and '50s.

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Posted by rrebell on Sunday, August 22, 2021 11:24 AM

ATLANTIC CENTRAL

 

 
Lastspikemike

Anything bought new in the last few years equipped with a dual mode decoder will run fine in DC mode if powered by a relatively new DC powerpack.

 

 

Completely wrong, old or new, if that DC throttle/power pack uses pulse width modulation, most, if not all decoders will go nuts.

 

 
Lastspikemike

Once you run DCC with sound regularly you won't think too highly of DC only. 

 

 

Says you. I have spent dozens, if not hundreds of hours operating the DCC layouts of my friends with sound equiped locos, After 15-30 minutes I can't stand the noise. Especially if there are multiple engines running (even at low volumes) and people trying to talk over the loco sounds.

To each there own, but don't assume you know what others like/want.

I will now defer to Tom's request and wait for a more detailed discussion elsewhere if it appears, and if not, that's ok too.

Sheldon 

 

I was strictly a DC guy but was hedging my bets with DCC ready locos way back. DCC did not appeal to me at my new abode as I was building a small railroad but a chance buy on e-bay of a MTH diesel with sound and a DCC starter set fo less than $200 got me to playing an a straight peice of track, got hooked on the sound, and then the other electronics like frog juicers etc.

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Posted by tstage on Sunday, August 22, 2021 11:22 AM

Lastspikemike
Once you run DCC with sound regularly you won't think too highly of DC only.

I agree with most of what Sheldon states.  While I, myself, like and use DCC, I am more into it for the independent control than the sound.  And, as far as sound, my tolerance level is higher for a steam locomotive than a diesel.  But even after a period of time my ears say enough and F8 (for mute) is a welcome alternative.  That allows me to listen to and enjoy the clickity-clack of the metal wheels crossing over the rail joints, which I find relaxing.

Tom

https://tstage9.wixsite.com/nyc-modeling

Time...It marches on...without ever turning around to see if anyone is even keeping in step.

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Posted by ATLANTIC CENTRAL on Sunday, August 22, 2021 9:46 AM

Lastspikemike

Anything bought new in the last few years equipped with a dual mode decoder will run fine in DC mode if powered by a relatively new DC powerpack.

Completely wrong, old or new, if that DC throttle/power pack uses pulse width modulation, most, if not all decoders will go nuts.

Lastspikemike

Once you run DCC with sound regularly you won't think too highly of DC only. 

Says you. I have spent dozens, if not hundreds of hours operating the DCC layouts of my friends with sound equiped locos, After 15-30 minutes I can't stand the noise. Especially if there are multiple engines running (even at low volumes) and people trying to talk over the loco sounds.

To each there own, but don't assume you know what others like/want.

I will now defer to Tom's request and wait for a more detailed discussion elsewhere if it appears, and if not, that's ok too.

Sheldon 

    

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Posted by JDawg on Sunday, August 22, 2021 9:19 AM

crossthedog

I just bought the engine of my dreams, the green-boilered Great Northern 2-8-0 Consolidated from Broadway Limited. I'm mainly interested in having a DCC buddy for my only other digital loco, so now I can take full advantage of my DCC operation by having more than one engine on the layout. I can already do that in DC because of the block wiring, and I have several DC locos to run. But the description says that this DCC loco also runs on DC. I'm skeptical because I've heard cautions and fail stories about that.

So here's my question: In your experience, can we really expect a DCC locomotive to run well in DC mode?

It doesn't even matter if the answer is "fuhgettaboutit". I don't have to run it in DC because I have the layout rigged to switch entirely over to DCC. But I am curious what others have experienced with DC/DCC locos.

Thanks!

-Matt

 

 

I think we have the same dreams. That engine is like a temptress. Buy me sir, I can be all yours for less than you think. Still talking about the engine by the way.  

JJF


Prototypically modeling the Great Northern in Minnesota with just a hint of freelancing. Smile, Wink & Grin

Yesterday is History.

Tomorrow is a Mystery.

But today is a Gift, that is why it is called the Present. 

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Posted by tstage on Sunday, August 22, 2021 8:47 AM

gregc
selector
It will still accelerate from a full stop, but only after the decoder gets about 6+ volts to activate the lights and the sounds if it's a sound decoder.

i'm curous.   have no real experience running DCC locos with DC

as mentioned, the DC voltage needs to be high enough to power the decoder processor after the voltage drops (~1.4V) across the bridge.

but at that point, does the same voltage go to the motor or does the decoder use PWM to more gradually increase the PWM motor voltage?

in other words, as the DC voltage increases from ~6V to ~12V, does the motor see a gradual increase from 0 to ~12V?

is the behavior the same for all decoders?

In order to avoid the "potential" hijacking of the thread and to help facilitate longer discussions on queries that are highly technical in nature (and, yes - this has happened more than once already this year), I would recommend starting a separate thread on the topic - Thanks.

Tom

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Time...It marches on...without ever turning around to see if anyone is even keeping in step.

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Posted by richhotrain on Sunday, August 22, 2021 8:34 AM

ATLANTIC CENTRAL

My advice, don't run DCC locos on DC, don't leave decoders in locos you plan to permanently run on DC.

Don't be on the fence, be DC or DCC.....

Sheldon  

As I look at this thread, and recently so many more like it, I am amazed that more and more guys want to run DCC locos on DC layouts, and DC locos on DCC layouts.

I get it. Some guys have operated DC layouts for years, accumulated a lot of DC locos, and just cannot convert to DCC for financial reasons, or sentimental reasons, or both.

But, I gotta agree with you in general, Sheldon. Why not one or the other? Or, run separate layouts if you have the space. Or, add a DCC powered track to your DC layout. Or, figure out a foolproof way, if there is one, to flip a switch to run either DC or DCC, one or the other.

Rich

Alton Junction

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Posted by ATLANTIC CENTRAL on Sunday, August 22, 2021 7:56 AM

gregc

 

 
selector
t will still accelerate from a full stop, but only after the decoder gets about 6+ volts to activate the lights and the sounds if it's a sound decoder.

 

i'm curous.   have no real experience running DCC locos with DC

as mentioned, the DC voltage needs to be high enough to power the decoder processor after the voltage drops (~1.4V) across the bridge.

but at that point, does the same voltage go to the motor or does the decoder use PWM to more gradually increase the PWM motor voltage?

in other words, as the DC voltage increases from ~6V to ~12V, does the motor see a gradual increase from 0 to ~12V?

is the behavior the same for all decoders?

 

Yes Greg, we know you are curous.

There are variations from decoder to decoder regarding how they perform on DC.

And then the bigger problem, it depends on WHAT KIND of DC you are using.

Very few power packs are pure, well filtered DC, and that is not the best way to control a motor on DC anyway. We all know by now that PWM is the best way to control a DC motor, that's why the decoder uses it.

The OP needs to understand that as long as DC operation is enabled, his loco will run on most "normal" DC power packs. How well it will run, its realitive top speed, and the comprssion of the speed range will vary with a lot of factors. 

I'm not going to try to explain them all.......

WARNING - if by chance a DC user is using a full voltage pulse width modulated (PWM for short) throttle, there is a good chance the decoder equiped loco will not run, or will run VERY poorly.

I have yet to find a dual mode decoder that will run on my ARISTO CRAFT TRAIN ENGINEER throttles. 

The behaviors are alarming. Some locos sit there and vibrate, others have two speeds, stop and full throttle, etc.

The high frequency pulses of the DC PWM throttle confuse the DCC side of the decoder. It does not know what to do.

VOLTAGE - Most "average" DC powerpacks are not well regulated regarding voltage. This makes up for some of the issues Greg is asking about. The no load voltage at full throttle of most/many DC packs is easily 14-16 volts, sometimes more, leaving plenty of headroom for the voltage that the decoder "sucks up".

Generally not the case however for those of us using more advanced DC throttles.

I use regulated and filtered 13.8 volt power supplies to feed my TRAIN ENGINEER wireless throttles. The TRAIN ENGINEER is just a throttle, it does not come with a power supply. It can handle up to 10 amps at 24 volts IIRC. It was designed to work with all scales up to and including large scale.

Sound equiped dual mode decoders are most annoying on DC........... but admittedly I generally find sound equiped locos annoying after 10 minutes in any case, so maybe my opinon does not count there.

My advice, don't run DCC locos on DC, don't leave decoders in locos you plan to permanently run on DC.

Don't be on the fence, be DC or DCC.....

Sheldon 

    

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Posted by gregc on Sunday, August 22, 2021 7:20 AM

selector
It will still accelerate from a full stop, but only after the decoder gets about 6+ volts to activate the lights and the sounds if it's a sound decoder.

i'm curous.   have no real experience running DCC locos with DC

as mentioned, the DC voltage needs to be high enough to power the decoder processor after the voltage drops (~1.4V) across the bridge.

but at that point, does the same voltage go to the motor or does the decoder use PWM to more gradually increase the PWM motor voltage?

in other words, as the DC voltage increases from ~6V to ~12V, does the motor see a gradual increase from 0 to ~12V?

is the behavior the same for all decoders?

greg - Philadelphia & Reading / Reading

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Posted by selector on Sunday, August 22, 2021 2:42 AM

crossthedog

 

 

 
Lakeshore Sub
I purposely disable DC functions on my decoders to prevent runaways during short circuits when straight DC current can sometimes be introduced to the track.

 

How does that happen, exactly?

 

Actually, I'm not even sure I understand what you mean by straight DC. If you run a DCC engine on a DC system, then isn't there straight DC going through the track the whole time? I guess maybe if it goes through the encoder then it has somehow become some OTHER kind of DC?

I'll consider giving the new engine a spin on DC when it comes, but the moment it looks or sounds at all weird I'm shutting that circus down. I'm more just curious about it in a theoretical way, and I've separated my DC from my DCC with a center off DPDT and the impossibility of having both systems' power sources plugged in at the same time.

Thanks for sharing your experience, Scott.

 

You disable the decoder's ability to operate in DC by altering the bits programmed into CV29.  That particular CV is very important in DCC world because it also controls your light operations, which end of a diesel goes 'forward', and so on.  If you google 'CV29 cal" you'll quickly find the search engine providing you with several sites with tables to determine which operating characteristics you want for the locomotive, and then it will tell you which value to programme into CV29.

The decoder only operates in DC.  It will accept the square wave alternating current, but it rectifies that AC into DC because that's all the can motor can use; it's a strictly DC motor.  So, while it might get DCC at the rails, it must decode the packets and then rectify the power going to the motor.  If it gets DC current, it won't have the packets and will behave differently.  It will still accelerate from a full stop, but only after the decoder gets about 6+ volts to activate the lights and the sounds if it's a sound decoder.

However, unless your decoder is configured to sense and to operate on both types of track power, it is a moot point as to what it will do in DC.  This is important because, in previous years, some decoders, not all of them, would take off like jackrabbits as soon as AC power came rushing into the rails in DCC.  The decoders concluded that they were being fed fully-dialed up DC and take off, usually with bad results.  The word got out that if one configured CV29 correctly, with the correct value, everything else would be unchanged, but the decoder would just sit when full DCC current became available again next time in a sudden rush.  The decoder was instructed to not act on DC current....so it didn't.

For decoders with values higher than 127 for an address, and not Add '03' as comes from the factory, a value of 34 in CV29 removes the ability to operate in DC, but all other features are maintained, such as lights and direction of travel.

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Posted by gmpullman on Sunday, August 22, 2021 1:45 AM

Before I "switched over" to DCC in 2005 I ran several Broadway Limited locos (they only had the GG1 and NYC Hudson back then) and they ran fine on DC. That was with old QSI decoders, though. The speed range is limited while on DC.

Good Luck, Ed

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Posted by crossthedog on Sunday, August 22, 2021 12:09 AM

Lakeshore Sub
I purposely disable DC functions on my decoders to prevent runaways during short circuits when straight DC current can sometimes be introduced to the track.

How does that happen, exactly?

Actually, I'm not even sure I understand what you mean by straight DC. If you run a DCC engine on a DC system, then isn't there straight DC going through the track the whole time? I guess maybe if it goes through the encoder then it has somehow become some OTHER kind of DC?

I'll consider giving the new engine a spin on DC when it comes, but the moment it looks or sounds at all weird I'm shutting that circus down. I'm more just curious about it in a theoretical way, and I've separated my DC from my DCC with a center off DPDT and the impossibility of having both systems' power sources plugged in at the same time.

Thanks for sharing your experience, Scott.

Returning to model railroading after 40 years and taking unconscionable liberties with the SP&S, Northern Pacific and Great Northern roads in the '40s and '50s.

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Posted by Lakeshore Sub on Saturday, August 21, 2021 9:53 PM

Hi Matt.

It will run in DC just not nearly as well since everything still goes through the decoder.  Your starting voltages will be higher and you will have a much smaller usable range on the DC throttle. I have tried running some my DCC lcomotives us DC and was not impressed.

You will also have to make sure that DC mode is enabled on the decoder or it may not work with DC voltage at all.   I purposely disable DC functions on my decoders to prevent runaways during short circuits when straight DC current can sometimes be introduced to the track.

 

The performance of DCC locomotives on DC varies so what you will experience is hard to say.

Your best bet is to try it out and see what happens.

Good Luck.

Scott Sonntag

 

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BLI 2-8-0 Consolidation - says DC and DCC, but is it really?
Posted by crossthedog on Saturday, August 21, 2021 6:07 PM

I just bought the engine of my dreams, the green-boilered Great Northern 2-8-0 Consolidation from Broadway Limited. I'm mainly interested in having a DCC buddy for my only other digital loco, so now I can take full advantage of my DCC operation by having more than one engine on the layout. I can already do that in DC because of the block wiring, and I have several DC locos to run. But the description says that this DCC loco also runs on DC. I'm skeptical because I've heard cautions and fail stories about that.

So here's my question: In your experience, can we really expect a DCC locomotive to run well in DC mode?

It doesn't even matter if the answer is "fuhgettaboutit". I don't have to run it in DC because I have the layout rigged to switch entirely over to DCC. But I am curious what others have experienced with DC/DCC locos.

Thanks!

-Matt

Returning to model railroading after 40 years and taking unconscionable liberties with the SP&S, Northern Pacific and Great Northern roads in the '40s and '50s.

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