BLI Pennsylvania M1a/b

[Joetrain59]

Should the headlight dim, or go out when loco is backing?
 Thaks,
 Joe D

[Lemosteam]

Yep.

[jdcolombo]

Should the headlight dim, or go out when loco is backing?
 Thaks,
 Joe D

This is actually not prototypical, but it is the way all DCC decoders (including sound) are set up from the factory.  You can usually change a CV in the decoder to keep the headlight on whether going forward or backward.

[Bob Bufkin]

Correct me if I'm mistaken but in the real world the PRR did not use headlights in the daytime during the steam era. 

[Mike C]

This is actually not prototypical, but it is the way all DCC decoders (including sound) are set up from the factory.  You can usually change a CV in the decoder to keep the headlight on whether going forward or backward.

If you could point me in the right direction on how to keep the headlight on in both directions I would be grateful ! I know it should be possible , but I just don't get the "bits" thing .

[Cajonpassfan]

Correct me if I'm mistaken but in the real world the PRR did not use headlights in the daytime during the steam era.

Nor did most of the other roads. On the ATSF, daytime headlight use didn't become a practice until 1953, and by that time the vast majority of ATSF steam locomotives were no longer in service. YRMV, but not by much. On the other hand, those headlights are so *cute*   
Otto K.

[nstars]

I was thinking of this very problem this morning.  I have a DC layout that has functioned very suitably over many years, but back when I built it,
I wasn't too knowledgeable about wiring.  (I have a couple posts about this on this thread two pages back.)  Now when I got my DCC K4, it ran
very well, beyond even my expectations.  Then I got the M1a, and it was a different story.  My track feed wasn't good enough, or consistent enough,
unfortunately, for the M1a. 

What I wonder about now is this: if I decide in the future to get another DCC locomotive I worry that I won't know in advance
whether it will run well like the K4, or if my layout won't sustain it, like with the M1a.  I wish there could be a rating, or some sort of indication, as
to the current requirements of each loco's decoder when it comes out.  I realize that the higher current requirement of the M1a is related to its quality
performance, but it would be great to have some idea beforehand about the decoder situation, so you could avoid getting a loco you can't run.

Our experience with sound decoders is, that most sound decoders are sensitive to current collection. Try for instance a Tsunami decoder without the capacitor and it hardly runs. The exception used to be the old Loksound V3.5 which used 100 ohm speakers (=less current) so the current draw is certainly a parameter. BTW the current Loksound decoders (select or V4) are also not bad, but still do require a capacitor when there is limited pick up. The reason why the K4 runs well is the fact that there are some nice big capacitors installed. Perhaps BLI should increase the installed capacitors size. However both our centipedes and M1's run without hiccup and the BLI E's we have needed run in time to remove the blackening on the wheels to get good performance.

Marc

[Jay Gould]

I'm smart in some ways, but electricity has always been difficult for me.  But thanks for that information---it gives me (and
maybe others) a start on information about the demands of various sound decoders, e.g., the Loksound (select or v4) being somewhat
tolerant of less than ideal current.  In my own case, I'm not planning much with these sound-type locomotives, but I am so pleased with
my K4 that I do hope to have (someday) a sound emitting freight loco to run (on DC, of course) when I'm running the K4.  The only thing is that
obviously I'll need one that will work.  Of course, if I was younger I'd try to improve my layout, but I'm no longer "younger" I'm sorry to say.
However, as it now exists, my railroad performs well enough and where the current happens to be a little slower is often, by complete
unplanned luck, right where the train should be slower, where it is passing by a station or through a yard.  But I couldn't run the M1a, so
I will be hoping to get another freight engine that I can run, and one that I can purchase with some confidence that I won't be returning.

[peteski]

Jay, to be honest, I think that your situation is a fairly rare one. Plus I'm still not convinced that it is an extra-power-hungry decoder which is the culprit.

The decoder's current consumption can vary by quit a bit (there are many variables like how many functions are turned on, the motor's current consumption, the locos speed and load, the volume of the amplifier).  Even if you came up with some sort of average current draw chart of various decoders, I'm not sure how useful that would be to an average model railroader.  It might more sense to spend that time getting more feeders to the track (again unscientifically assuming that that's where the problem is). 

Then there is also a possibility that your M1 is defective.

[Jay Gould]

Peteski--Now I'm not very knowledgable about electronic stuff, but maybe all of the decoder accessories were turned way up at the factory, maximizing current demand---I'd read some posts earlier that noted that, and the headlight on my M1a was turned up bright enough to do surgery.  I never tried to turn it down because I was already preoccupied with the loco's unruly stalls and speed-ups, and besides, I don't yet own a hand held device to control individual loco functions, since I don't have DCC in the first place---so I never dimmed the headlight or anything else.  (I don't know if that observation is helpful---but there it is.) 

In any case, it was nothing like the easy success of the K4, and as I say, I hate to return something I bought.  It makes me feel kind of guilty.  But thanks a lot for your analysis.  At least I'm gradually getting a better understanding of the situation.

[peteski]

Peteski--Now I'm not very knowledgable about electronic stuff, but maybe all of the decoder accessories were turned way up at the factory, maximizing current demand---I'd read some posts earlier that noted that, and the headlight on my M1a was turned up bright enough to do surgery.  I never tried to turn it down because I was already preoccupied with the loco's unruly stalls and speed-ups, and besides, I don't yet own a hand held device to control individual loco functions, since I don't have DCC in the first place---so I never dimmed the headlight or anything else.  (I don't know if that observation is helpful---but there it is.) 

In any case, it was nothing like the easy success of the K4, and as I say, I hate to return something I bought.  It makes me feel kind of guilty.  But thanks a lot for your analysis.  At least I'm gradually getting a better understanding of the situation.

I was just generalizing that it would be a bit difficult to come up with an average power consumption of various sound decoders.   The headlight by itself might be bright, but it is a very efficient white LED. Maybe is consumes about 0.02A when brightly lit and maybe around 0.005A when dim. But that is relatively small amount of current when compared to what the motor consumes (probably around 0.25A at full throttle.

Do you have friends with N scale layout or maybe a model RR club?  It would be interesting to see how your M1 runs on another layout.

[Jay Gould]

That's right, I forgot how completely efficient these new LEDs are!  But thanks again, for the help.

As to other N scale layouts in my area, I don't know of anybody in the area right now who has an N scale layout.  We had an NTRAK club once, 10-12 years ago,
but a few key members died or moved away and the remaining people couldn't be harmonious.  I still see now and then one guy from the club, but he no longer
has a layout.  That would be a great idea, though.  I wish I'd thought of it, because if I tried I could probably have located someone, maybe through the local railway
historical society.  But I already sent the M1 back, anyway.  At this point I'm just trying to get some idea of the terrain with DCC/sound, for future reference.

I could possibly have freight trains this way: I have a Con-Cor set of PRR Merchandise Service cars, and Con-Cor sold the original set with a K4 at the head end.
I don't know if prototypically they ever had a pacific at the head end of such a train, but Con-Cor thought so, so maybe I could see about getting another K4, using these
express freight cars, just to tide me over.  I am double tracked, and I really would like to see, not one, but two locos chugging along at the same time.

In the meantime, I have lots of other stuff, including a new-found strong interest in the DL&W, things like that to keep
me occupied as I slowly get the picture about this new technology.

[chicken45]

I could possibly have freight trains this way: I have a Con-Cor set of PRR Merchandise Service cars, and Con-Cor sold the original set with a K4 at the head end.
I don't know if prototypical they ever had a pacific at the head end of such a train, but Con-Cor thought so, so maybe I could see about getting another K4, using these
express freight cars, just to tide me over.

I don't think Merchandise Service cars ran as a unit train. I think they were LCL things and were peppered in where needed. "Typical Con-Cor."  They weren't even used in express services, right? Strictly freight? Like, you wouldn't seem them being MS60'd* on a mail train, would you? So, if they were strictly freight, they may not have been pulled by a K4. To me, the guys at Con-Cor probably thought they were used as some sort of express service like a mail train or fast freight or something.


*http://www.pennsyrr.com/index.php/forum/faq/6-faq-what-is-an-ms60-passenger-car

[Jay Gould]

The New York Central had their gray and red "Pacemakers" which were often cited as comparable to the PRR Merchandise Service, and I understand that the Pacemakers WERE often
run as unit trains.  I don't doubt that with these Merchandise Service cars Con-Cor was probably operating on a myth, but in this case I just may go along with the myth.  Nevertheless I
always do appreciate authentic information, and I usually try to follow it.

By the way, there was a guy in our club who had about fifteen beer can tank cars, and he would arrange them in a train according to their colors, sort of like a rainbow.  That kind of thing
I would never do.  But a Merchandise Service unit train (with a few REA box cars at the front), well maybe!

[eric220]

I think Con-Cor's reasoning may have simply been that it was a prototypical PRR steam locomotive that was available.