Daylight, the RFD TV channel's Trains & Locomotives program last week was a history of the SP Daylight.  I recorded it but haven't watched it yet.

Bill

Jward, no, I don't hear a clicking sound when I start my BlueLine locomotives.  My experience with DC locomotives, like the Lifelike F7 with my first HO train set, is that they start & stop quickly.  Maybe better DC locos operate more smoothly.

Jim, thanks for your detailed explanations.  In my BLI DC with sound Heavy Mikado, having its own sound decoder, I installed a Digitrax DN143IP motion decoder, because it was at the top of the list of recommended decoders in the Mikado's manual.  I have EZ Command.  I turn the throttle very slowly, hear the Mikado wake up, turn more & then see it move.  The best I can do is minimize its lunge to avoid uncouplings.  It can pull 16 cars at about 120 mph.
When I ordered the BLI SD40-2, I also ordered a Digitrax DN143IP for it.  When I received them, I saw that the manual listed a Digitrax DZ143PS as the top choice.  The SD40-2 reacts like the Mikado:  after it awakes, more throttle makes it move, & it wants to lunge.  It pulls 14 cars ranging in length from 40' to 75' at 100 mph, & it probably isn't completely broken in yet.
You lost me a few times, but I did not get sleepy.    Now, I know that top speed & momentum are not connected.  I've ordered The Dcc Guide: How to Select and Use Your Command Control System by Don Fiehmann, & I may buy a Digitrax Zephyr, if only for programming.

Bill

Quote from: Jim Banner on May 22, 2009, 02:49:00 PM

I am not sure if Mathew has N-scale or H0-scale GP-50s so here are some thoughts on Digitrax decoders for both scales:

N-scale -  DZ123 (low cost) or DZ125 (includes BEMF)

H0-scale - DH123 (low cost) or DH163 (includes BEMF and four extra function outputs)

BEMF stands for Back ElectroMotive Force, which is the voltage generated by a motor when it is turning.  This voltage is measured by a BEMF decoder and compared to a voltage that represents the speed you set via your throttle.  If the motor is going too fast or too slow, the decoder makes the required corrections.  In this respect, it is rather like cruise control in an automobile.

Where BEMF control really shines is at low speed.  With most locomotives, you have to set the throttle to about 30% to get the locomotive to start.  Then it runs, but often faster than the slow crawl you would like.  But with BEMF, you set the throttle to say 1%.  If the motor does not start, the decoder ups the voltage until it does.  When it does start moving, the decoder will reduce the voltage before it moves too fast.  The result is a locomotive that starts smoothly and runs smoothly throughout its speed range, including the all important low speeds.  This is ideal for switching freight cars and just as great for pulling a passenger train out of the station without spilling a single bowl of soup in the diner.

Jim, if I had installed BEMF decoders (which I didn't know about until I read your post) into my BlueLine DC with sound locomotives, would they then have momentum, instead of lunging at start & stopping suddenly? 

Also, does momentum decrease the top speed of locomotives?  I wonder because my 4 Bachmann locos with DCC onboard have top speeds of about 80 or less, while my 2 BLI DC with sound into which I installed DCC decoders, have top speeds of 100+.

 I solved the problem with the ditch lights by moving the 4-wire plug back from J7 to J1.  I can still turn the headlights on & off, but the ditch lights remain on. 

While it creeps smoothly, its Digitrax DN143IP, like the one in my BlueLine Heavy Mikado, needs to have momentum programmed into it.  I gave it the same address as my Spectrum SD45 for possibly running them in consist occasionally.  However, the Spectrum pulls my 14-car UP train at a top speed of 80 HO mph, but the BlueLine SD40-2 pulls it at a top speed of 100!  I wish I'd known what Jim Banner just posted at the thread DC to DCC Conversion, that some Digitrax decoders come with BEMF, which "stands for Back ElectroMotive Force."

 Four months after I pre-ordered it, my BlueLine DC with sound SD40-2 UP arrived.  Monday, Tony's Train Exchange called to say that they were ready to ship, but my credit card had expired.  I was told that some BLI preorders take 3 years.  I suppose some of the customers expire during that time!

After running it in DC, I installed a Digtrax DN143IP DCC decoder.  Since I'd left my BlueLine DC with sound Heavy Mikado on address 3 after I'd installed a DCC decoder, I wondered whether the separate sound & DCC decoders would work at a different address.  I had no problem changing the SD40-2's address from default 3 to 4 with EZ Command.  I also changed the 4-wire plug from J1 to J7, because I wanted to be able to turn the lights on & off from my EZ Command.

I like its horn!  It sounds like what I hear, clearly, from the railroad a mile away from inside our house with the windows closed.

One of the oscillating ditch lights does not come on.  I think both worked in DC.  I'll wait a day before removing the couplers & shell & putting all that back together again.

 Thanks, Joe & Rusty, for the information about where to get those books.

 Thanks, Atlantic Central, but I just looked up Operation Handbook for Model Railroads on amazon.com, where the cheapest used copy is $45!

I enjoyed the further discussion.  Maybe I'll let someone else answer the question on relativity.   

  Yes, I will try to slow my trains down!

 Thanks for the information & interesting discussion.  Thanks for the link, Bob.
  This question occurred to me:  suppose my layout is 1/2 HO scale mile & I am running my train at 50 HO scale mph.  If I speed my clock from real time to 10 x real time, so that my layout now seems to be 5 miles, is my locomotive still travelling 50 mph?  I suppose the speed remains the same.
  I also find it interesting that we use real time to calculate scale speed for scale distances.  Scale time just doesn't seem to fit.

 Reading the manual for MRC Prodigy Advance, I found Fast Clock & settings for time ratio.  The manual is too brief to explain the use for such a feature (or its other complex features) but refers one to "How to Operate Your Model Railroad" by Bruce Chubb.  I looked up the book on amazon.com & found that it was published in 1977 & costs $49 used!   HO minutes & hours don't seem to equate with HO feet & miles.

Rusty, apparently, if I wanted to use my Bachmann 5 amp booster with a Digitrax Zephyr, I'd have to create a second power district insulated from the first (which I'd have to learn how to do).  So I see another thing I like about EZ Command:  connecting it to the booster.  It's too bad any booster can't be connected to any DCC control.

Ray, I hate to think what it would cost for Tony's to program a decoder they'd installed.

 My first kit was an Athearn caboose costing $7.  The weight was already attached.  I was happy with the result. 
My second was an Accurail boxcar costing $11.  I had to glue the weight but it soon fell off.  A closer look revealed that the floor was warped, so I clamped the floor to the weight to make all of both surfaces touch.  The couplers came in halves with the pin a third piece, the poorest couplers I've seen.  When they open, they stay open & must be closed by hand.

 I watched, for the first time, RFD TV's I Love Toy Trains.  It was about accessories, specifically Lionel.  I was impressed with several of them.  I like the mail car that snags a mail bag off a trackside pole, & the water tower that used real water that was pumped down to simulate filling the boiler & then pumped back up to simulate refilling the water tank.  The narrator evaluates each item for collectors' value.

TCline, we live 25 miles from the nearest city with broadcast HD channels & 65 miles from a big city, so we couldn't get much.  I'd love to choose only the channels I want to pay for, but cable & satellite companies have more influence in Washington than consumers do.  I switched from cable to satellite, because cable is a monopoly in our town, but we have a choice of two satellite dish companies.  It isn't fair that DirecTV requires us to lease their HD receiver, instead of buying it, but charges us to repair it or buy a service contract. 

Thanks, Rusty.  My LifeLike power pack has no pulse power switch.  I'd prefer to be able to use it rather than pay $60 for a throttle in addition to buying a Zephyr.  Some have bemoaned that Digitrax has not improved Zephyr since it won awards in 2002.
  One reviewer said,  "It definitely needs an LCD panel with a menu driven interface. Personally I'd like a recall switch that let's you toggle the last two locomotives without having to enter an address." http://modeltrains.about.com/b/2008/07/28/does-digitrax-need-a-new-zephyr.htm

 Then buying throttles would become expensive.