Speed matching an FA and an FB diesel unit

[rbryce1]

I have 3 Erie Lackawanna diesel units, one is an A unit with sound, on is a B unit with sound and the third is an A unit without sound.  I am trying to make a consist from the A unit without sound and the B unit with sound.  The A unit is traveling faster than the B unit to the point where the A unit is growling slightly like a laboring motor.  The A and B units (both with sound cards) seem to match each other's speed almost perfectly and do not produce this noise.  If I watch carefully at the couplers, the A and B units that have sound pull evenly when starting out. When the A unit without sound and the B unit with sound start out together, there is a sharp snapping tug on the B unit by the A unit.

Does a sound card affect the engines voltage to the point where I will see this much difference in torque or is it something else.

I am running with a Bachmann Dynamis controller and no other loads on the layout.

[Jerrys HO]

Do a search of this forum for speed matching. A lot has been discussed on this issue.

[richg]

Sound has nothing to do with this.
You have to tweak the some CV's for proper speed matching. Check the Bachmann DCC documents for the CV's that have to be tweaked. They are in the Bachmann site, under Parts & Service.
There is a learning curve.

Rich

[railtwister]

If I recall correctly, the FA's from Bachmann are available from the factory with the Sound Value decoders from Soundtraxx, or as DC-Ready with no decoders and a jumper installed in the DCC socket on the light board. This would mean that the non-sound loco has a user-installed decoder in it now, correct? Depending on which decoder you are using, you may or may not be able to adjust the CV that control speed settings to match the Sound Value units. Soundtraxx offers some non-sound mobile decoders that are designed to match up with their sound decoders, so this might be an option for you if you are unsuccessful in your speed matching attempts. Be advised that while all versions of these decoders are attractively priced, not all are capable of also running in analog mode, if that feature is important to you, so be careful which one you choose, and call Soundtrax directly if you have questions. Here's a link to the mobile decoder page: <http://www.soundtraxx.com/MotorDecoders/MotorDecoders.php>

Bill in FL

[rbryce1]

Bill,

You are correct in what you assume.  The A and B units did come "Sound Equipped" and the other A unit was DCC ready.  I purchased Bachmann's decoder and converted it to DCC equipped without sound.  I am looking into whether I can adjust with CV's or not.  If not, I may just get a sound card and make them all sound ready, and couple the two who are working well together as an A-B unit instead of the way I wanted to do it, a non-sound A unit with the sound B unit.

[wjstix]

Putting a sound decoder in the silent engine won't make it go slower. Two sound equipped models of the same engine don't necessarily run the same speed.

If you have a programming track and can read back CVs, put the fast engine on the programming track and read CV 5. It will probably come back "0" meaning the engine is bypassing the speed control CVs. Change CV 5 to say 200 (256 is the max) and see how it runs compared to the other engines. If it still needs to slow down, put in a lower number. If it's now a little too slow, increase the number a little.

[jward]

according to bachmann's literature, cv5 and cv6 are not supported. these are essential for speed matching, controlling the top and mid range voltages. you may have to adjust your sound equipped locomotives to run with the non sound one, instead of the other way around.

[rbryce1]

These are all three Backmann engines.  What if I just install a sound card in the non-sound engine?  Will CV5 & 6 be available then?  I really like the sound of the Tsunami card much better than the low cost card that came in the other engine.

[wjstix]

OK, don't panic!! 

First we're not talking about sound cards, those are in your computer...we're talking about decoders to control a model railroad engine.

You have three engines with decoders, two have sound decoders and one with a non-sound decoder. The non-sound Bachmann decoders are pretty basic decoders, and don't allow you to adjust the speed of the engine with CV 5 and 6. (They're about the only decoders now out there that don't have that capability.)

That means you can't slow that engine down to make it match your sound engines, but all you have to do is take it out and replace it with a better non-sound decoder. If you want to spend $100 for a Tsunami sound decoder, that would work. However a good non-sound decoder from NCE, TCS, Digitrax etc. will run you around $18-25. Personally, I'd go with TCS because they work well and have simple easy-to-follow instructions.

Once you have a new decoder in the non-sound engine, you can adjust CV 5 and 6 down to limit it's speed, and you should be able to run all three engines (or any two of the three) together with no problems.

[BlueFox]

I have converted 14 Bachmann FT-A & B's and 5 GP-40's with NCE drop-in replacement decoders with no problems.  Just a little playing with CV's 2, 5 & 6 (if needed) and I had them all running fine in their respective consists.  Even one of the FT-B was a DC  model and after replaceing the OEM DC board with a NCE decoder mentioned above it ran fine, too.

Frank