Bachmann DC weirdness

[UncBob]

 I am running two ovals--18" and 22" with DC

 

I have 2 MRC Sound and Power 7000 supplies

 

I can switch the  supplies between the ovals

In addition to other manufactuer steamers I have Bachmann  2-8-0  2-8-4  4-8-2  4-8-4

All Bachmann are DCC equipped and I have inserted the jumpers  to bypass the DCC

The 2-8-0 and 4-8-2 and all my non Bachmann have no problems with either supply

The 4-8-4  and 2-8-4 will only run in reverse on supply A  --they run OK on supply B

 

Any ideas ?

 

 

[wjstix]

Just a shot in the dark, but maybe take the dummy plug out, turn it 180 degrees, and put it back in. If it's put in wrong-way-around it might explain the problem(??)

BTW I thought Bachmann decoder-equipped engines came with "dual mode" decoders that worked on either DC or DCC with no modifications needed??

[cacole]

 If the Bachmann engines are all DCC equipped there's no dummy jumper to install.  If they have a dummy jumper, they are NOT DCC equipped, just DCC ready.  And turning the dummy plug around will make no difference because the plug is the same either way.

When you say they run backwards, do you mean they will run only backwards, or backwards to the direction of the other locomotives.  If backwards to the other locomotives, reverse the connections to your power pack.

Or buy a DCC system and eliminate all of these problems.

 

[UncBob]

 Only run backwards

[ATLANTIC CENTRAL]

cacole

If the Bachmann engines are all DCC equipped there's no dummy jumper to install.  If they have a dummy jumper, they are NOT DCC equipped, just DCC ready.  And turning the dummy plug around will make no difference because the plug is the same either way.

Obviously you are not familiar with Bachmann Spectrum locos. The DCC versions come with dual mode decoders, plugged into a factory DCC ready lighting control board. They also include jumpers for DC users to use in removing the decoder and restoring pure DC operation.

The dual decoders Bachmann uses, and many other dual mode decoders I have had experiance with run very poorly on many types of DC throttles. So many of us in DC remove any/all factory supplied decoders to restore the high performance of our nice throttles.

Bachmann has chosen this route rather than offer three versions, DCC/sound, just DCC, and DC. Their pricing makes it acceptable to purchase the DCC versions and remove the decoder, inserting the two metal jumpers provided.

To the OP, you may have defective light boards in these locos, call Bachmann.

cacole

Or buy a DCC system and eliminate all of these problems.

This is an un-called for comment - since those of us who use DC to do not post smart remarks in every DCC problem posted on here. And it seems every day there are a number of such posts. Yet very few posts with DC problems like this one.

Sheldon

 

[ATLANTIC CENTRAL]

davidmbedard

The OP is trying to use DCC products in a DC environment.  Even a Bachmann EZ DCC system would improve his experience in this case.....

 

David,

The OP stated he removed the decoders and installed the jumpers provided by Bachmann. His reference to DCC is only to explain which version of Bachmann product he bought and what he has done to it.

I have many such Bachmann locos which I too have removed the decoders and installed the jumpers.

So, if the OP has explained himself correctly, he is not using a DCC product at all, but has converted it back to a DCC ready, DC product as per instructions provided with it by Bachmann.

I remove ALL DCC decoders from the few locomotives I buy that way regardless of brand. All dual mode decoders perform poorly on DC in my experiance.

I suspect there is a problem with the directional constant lighting circuit in the problem locos. Bachmann will gladly replace them based on my experiances.

Sheldon

 

 

[UncBob]

 They  only do it on one power supply -they  run OK on the other and on a 3rd that I have

 

So I can use my layout no problem by using the right supply for the track the engine is on

 

However it seems weird that the situation exists 

 

My end to any DCC/DC problems would be to bypass the tender altogether  and tying the wires together at the engine --I did this on my Bachmann 2-8-0 back in 99 to eliminate the wires which I thought looked goofy from the engine to the tender and no I never had a problem in 10 years of running it without the extra pickup from the tender wheels--pic attached

 

I would do that to all  my steamers if it wasn't such a pain working with the small wires

 

I pefer the sound from my MRC 7000  anyway so I don't need sound from the tenders

 

 

 

 

 

 

[ATLANTIC CENTRAL]

UncBob

The 4-8-4  and 2-8-4 will only run in reverse on supply A  --they run OK on supply B

UncBob,

OK, a question.

Are both sound and power systems set to the same pulse settings. I still suspect the lighting boards boards but different settings on each power supply could explain why the problem is with one and not the other.

You have removed/bypassed the decoders as you discribed, correct?

Sheldon

[ATLANTIC CENTRAL]

UncBob,

You need to understand that the other circuit board in the loco has NOTHING to do with DCC. There are no DCC related components left once you install the jumpers. The remaining circuit board is strictly for the DC directional constant lighting.

While it may be the cause of the problem, the problem has nothing to do with DCC. You removed any chance of that when you installed the jumpers, A much better choice than loosing the lighting controls and tender pickups by bypassing the tender.

Sheldon

[rrinker]

 Question. Those capacitors and choke coils that Bachmann uses to reduce RF interference usually cause lots of problems with the PWM drive from a DCC decoder. I'd expect that they'd cause the same problems if the power coming over the tracks was also PWM.

                            --Randy

 

[ATLANTIC CENTRAL]

Randy,

They cause no problems with DC, even Pulse Width DC. I use the Aristo Train Engineer and have a large fleet of Bachmann Spectrum, they all run great on the Pulse Width Modulated DC of the Train Engineer.

But, if there is a defect in the directional circuit, that might cause a problem.

Sheldon

[UncBob]

ATLANTIC CENTRAL

UncBob

The 4-8-4  and 2-8-4 will only run in reverse on supply A  --they run OK on supply B

UncBob,

OK, a question.

Are both sound and power systems set to the same pulse settings. I still suspect the lighting boards boards but different settings on each power supply could explain why the problem is with one and not the other.

You have removed/bypassed the decoders as you discribed, correct?

Sheldon

ATLANTIC CENTRAL

UncBob

The 4-8-4  and 2-8-4 will only run in reverse on supply A  --they run OK on supply B

UncBob,

OK, a question.

Are both sound and power systems set to the same pulse settings. I still suspect the lighting boards boards but different settings on each power supply could explain why the problem is with one and not the other.

You have removed/bypassed the decoders as you discribed, correct?

Sheldon

 

These units are from 97-99 time frame --I am not sure what you mean by pulse settings

[ATLANTIC CENTRAL]

UncBob,

Your sound and power units have a switch for pulse power? Yes? Is it on or off? Is it the same on the two that work and the one having the problem? If you do not have an external switch for pulse power, it may be "automatic" and could mean the power pack with the problem has an internal problem in the pulse power circuit. When running on the problem unit, with a loco that works fine everywhere, does the range of speed control seem different on the problem unit compared to the others? If so that would point to what I discribed above.

There are no settings in the loco. Once you have removed the decoder and installed the jumpers, they are truely just DC locomotives.

Sheldon

 

[UncBob]

 MEA CULPA     MEA CULPA     MEA CULPA

problem solved well sorta

 

I knew I had switched over my DCC engines by installing the plugs  onthe 2-8-0  the 4-8-2--the 2-8-2

But thinking back I wasn't going to run a 2-8-4 or a 4-8-4 on a 22" oval  but I gave it a try and they ran OK so I added them to the ME&O steamline up

 

They had been working OK on the 22" oval with its power supply  --so when I switched the 22 to the other MRC 7000 and they didn't I couldn't figure what was wrong

 

Double checking I just  I took the tenders apart and --NO Plugs  --I put them in and now they work

 

HOWEVER that does not explain why they worked on one and not the other supposedly identical supplies 

 

Sheldon -- On the 7000s I don't see any switch etc for a pulse  adjustment--they come with Momentum--Brake -- Nudge plus Sound adjustments

[ATLANTIC CENTRAL]

UncBob,

Your sound and power units may seem identical, but they may be different internally from different production runs.

Since you still had the dual mode decoders in the two problem locos, there is a good chance the automatic pulse circuit is different in that one and it did not get along with the dual mode decoder - nothing new. As I said, I ditch all the decoders.

I looked it up in some old catalogs and the sound and power 7000 has an automatic pluse power circuit of some kind, so what I discribed above is most likely the case.

Sheldon 

 

[UncBob]

ATLANTIC CENTRAL

UncBob,

Your sound and power units may seem identical, but they may be different internally from different production runs.

Since you still had the dual mode decoders in the two problem locos, there is a good chance the automatic pulse circuit is different in that one and it did not get along with the dual mode decoder - nothing new. As I said, I ditch all the decoders.

I looked it up in some old catalogs and the sound and power 7000 has an automatic pluse power circuit of some kind, so what I discribed above is most likely the case.

Sheldon 

 

Well that is about the only thing that makes sense --So thanks for the reply