Decoder Question...

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rhoward

S.L.O.&W. Trainman
Howdy!

I have gotten my brand new HO Spectrum 4-4-0 out of the box and I am getting it ready for service on the S.L.O.&W. Looking at the specs on the elcheapo decoder that comes with it, they have been purposefully vague about the speedsteps available in CV 29. In some places it says 14/27 or 28/128, in other places it says can use 14, 27, 28, and 128 speed steps. In the PDF that is downloadable it says CV29 bit 8 0=14/27, 1=28/128. All my present decoders are 128 speed steps and I want a decoder in this little beauty that also respons to 128 speed steps.

Can any of you clarify if the Bachmann decoder does indeed respond to 128 speed steps when set up properly? I wouldn't have noriced this probably but the loco does about 200 scale miles per hour at speed setting 29........... I don't run sound so a 2 function decoder is all I want and need for steam in 1925.

Thanks in advance!
 

HaggisKennedy

Coal Shoveler
Dunno. I'd put CV29 to '1' and see what happens. I think as far as the documentation is concerned, the decoder will respond to whatever the command stations says to do; I would expect that to be the case to be fully backwards compatible (as in, somebody out there has a command station that runs on 14 speed steps).

I think if your DCC system can do the 128 speed steps, the loco will as well, once you set CV29 to '1'.... Try it and let us know.

BTW, if the loco does Warp 5 as a top speed, you'll need to fiddle with the vMax setting.

Kennedy
 
Lenz Decoders Installed in Spectrum Locos

All my present decoders are 128 speed steps and I want a decoder in this little beauty that also responds to 128 speed steps.
Yes, the newest generation of Lenz decoders that are factory installed will operate in 128 speed step mode. However, that doesn't mean they will operate "well"... If you're in the mood to replace this cheapie decoder, install a decoder by NCE in its place. They are, in my experience, the most reliable decoders in the marketplace, and they come with excellent, easy to comprehend documentation.
 

SpaceMouse

Fun Lover
I don't run sound so a 2 function decoder is all I want and need for steam in 1925.
I'll tell you what, I'll send you a nice decoder and you send that nasty old sound decoder to me. I'm pretty sure I have an NCE sitting around.
 
Last edited by a moderator:

rhoward

S.L.O.&W. Trainman
Thanks all!

Chip, I'll gladly send you that decoder that I am taking out. No sound though. Under the right circumstances, you might get it to smoke.....:rolleyes: :eek:

After doing some asking at a DCC guru in the Rochester area, I have ordered some NCE D13SRJ decoders (I could get a 4 pack very cheap, under $12 each and yes they are a great decoder). My locos are about half Digitrax and half NCE Decoders. Very pleased with both.

BTW CV29 is set to 1 from the factory. The box proudly proclaims that it will run at 28 speed steps. Then says in the documentation that if CV29 is set to 1 you get 28/128 speed steps....?
 

NZRMac

In Training Down Under.
I have all mine set to 28, just so I don't need to push the throttle button so many times:eek:

Ken.
 

HaggisKennedy

Coal Shoveler
You wrote:

> Then says in the documentation that if CV29 is set to 1 you
> get 28/128 speed steps....?

That's because if your command station can issue instructions at 128 speed steps, it will do so. 128 speed steps is actually an extrapolation of the values that are set in the 28 speed steps.

If you look at your speed curve CV values, there are only 28 of them (CV67 to 95). It's physically impossible to program 128 individual speed values into your decoder. So, the command station does the extrapolation. Basically 4.5 increments between each of the 28step increments. At least that's what my calculator says!

Kennedy
 
That's because if your command station can issue instructions at 128 speed steps, it will do so. 128 speed steps is actually an extrapolation of the values that are set in the 28 speed steps.

If you look at your speed curve CV values, there are only 28 of them (CV67 to 95). It's physically impossible to program 128 individual speed values into your decoder. So, the command station does the extrapolation. Basically 4.5 increments between each of the 28step increments.
That's the best explanation I've seen, yet! :D
 

hminky

Member
The decoder that is supplied in Bachmann's products is really crappy. I couldn't believe their lack of performance until I replaced them with a Soundtraxx Tsunami in my On30 2-8-0's, night and day.

Probably Lenz is dumping all their old chips and crap, in the days of the good $12 DCC decoder they could have easily done better.

Just a thought
Harold
 

rhoward

S.L.O.&W. Trainman
The decoder that is supplied in Bachmann's products is really crappy.
Harold
That is exactly what Tim at Empire Northern said, and what my experience with the 4-4-0 was. I figure that another $15 to get an NCE decoder in it was a reasonable upgrade. Decoders should be arriving today (also ordered 4 Digitrax 1.5" wiring harnesses - NMRA Medium plug). Not bad $63.98 for the lot.
 

HaggisKennedy

Coal Shoveler
That's the best explanation I've seen, yet! :D
Looking at my post again, I have to clarify what I originally said regarding the extrapolated increments. It's still appx 4.5 step increments, but the value of each 'increment' is based on the total range value of the speed curve. If SS 28 (max speed) is 255, and the curve is linear, then the value between each value is 9 (255/28). Then, to me, if you apply the 4.5 step increments for the 128ss, you're looking at each speed increase value of 2. Which is what the command station will send to the loco, and it's speed increases accordingly.

If the 28ss values are less, say 6, then you're talking 6/4.5, or 1.3. Which means a slower increase in speed. Some people program individual values into each CV, and that would change the values sent by the command station to the loco.

I know nothing about what each 'value' means to voltage...

:D

Kennedy
 

rhoward

S.L.O.&W. Trainman
Just a quick update. I just installed a NCE decoder into the 4-4-0. What a difference! I will still take some tweaking, which i expect with all my locos, but it now runs at a much more realistic speed at half throttle.

Chip, you want the Botchmann crapolla decoder? I will probably keep it for "emergency use".......maybe.
 




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