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One or two decoders?

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  • Member since
    April 2008
  • 113 posts
Posted by AlienKing on Wednesday, August 7, 2024 10:36 PM

If you end up using only 1 decoder and sending wires to the other engine, run 2 extra wires for a speaker in the other engine as well.

  • Member since
    September 2014
  • From: 10,430’ (3,179 m)
  • 2,311 posts
Posted by jjdamnit on Friday, August 2, 2024 1:56 PM

Hello All,

ndbprr
I can put one sound decoder in the first engine and send the motor connection by wire to the second engine and the rear headlight for backing instead of hooking up the first rear headlight.

Realistically- -Yes you can.

Practically- -That's another matter...

Because I run several consists on my HO pike I have gone so far as to standardize the motors, and gear towers in each consist along with the decoders.

Even with the standardization I still have to adjust CVs to speed match to get the best performance from each consist.

I've recently begun to switch some of the decoders to sound versions of the same brand.

My non-sound decoder of choice is the Digitrax DH166D (superceeded by the DH187D).

The new DH187D is relatively inexpensive and can be found for under $30.00. If needed, it can be fitted with a PX108-2 Power Xtender (superceeded by the PX112-2) for under $25.00.

I am replacing the non-sound decoders with the SDxH167D with a PX112-10 Power Xtender.

These sound decoders plug into the existing 9-pin Digitrax harness used for the DH series non-sound decoders.

Sound Upgrade H10-44 in HO

Physically linking two motors to one decoder requires a decoder that can handle the total stall current of both motors- -approximately 1.5 to 2.0 amps.

To be safe a "high capacity" decoder should be used.

Digitrax makes a sound decoder rated at 4 amps/5 amps peak. At an MSRP of $89.00 and can be fitted with a PX112-2 Power Xtender for an additional $25.00 (less than MSRP).

ndbprr
A pair of plugs is cheaper then (SIC) another decoder.

You would need to install two (2) sets of plugs; Gray, Orange, Blue, and Yellow.

Now factor in the cost not only of the plugs but also the decoder wire (30AWG), shrinkwrap, and the tools and time for the project.

The consists on my pike are often broken to provide mid-train and/or pusher duties.

Obviously, this would not be possible if they were hard-wired together.

I would install two (2) separate decoders and MU them through universal, basic, or advanced consisting with the ability to speed match- -even with the same type and manufacturer.

Hope this helps.

"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"

  • Member since
    December 2004
  • From: Bedford, MA, USA
  • 21,483 posts
Posted by MisterBeasley on Thursday, August 1, 2024 4:44 PM

kasskaboose

Interesting idea!  Not to hijack the thread, but I have some questions:

Does it matter whether the locos are facing the same direction?  Does each loco need a decoder?

That's another thing easily solved with a pair of decoders, even though it’s not a big deal to wire.  However, if you want to use a hardwired solution, you have to rewire it to make a change.

My secondary decoders are really basic and simple.  Motor and end headlights is all, no ditch lights or fancy stuff.  These cheap decoders make swapping directions easy and are so cheap they make it easier than even a quick rewire.

Swapping direction of one loco in a consist is a simple consisting function.

It takes an iron man to play with a toy iron horse. 

  • Member since
    February 2008
  • 2,360 posts
Posted by kasskaboose on Thursday, August 1, 2024 4:13 PM

Interesting idea!  Not to hijack the thread, but I have some questions:

Does it matter whether the locos are facing the same direction?  Does each loco need a decoder?

 

  • Member since
    December 2004
  • From: Bedford, MA, USA
  • 21,483 posts
Posted by MisterBeasley on Thursday, August 1, 2024 2:28 PM

I have a few pairs of engines I generally run as consists, Geeps and F Units.  Most are pairs, with a sound unit in one engine and a simple motor-and-lights decoder in the other.  This works for me, and having headlights at each end gives me two-way operation.

It takes an iron man to play with a toy iron horse. 

  • Member since
    February 2002
  • From: Mpls/St.Paul
  • 13,892 posts
Posted by wjstix on Thursday, August 1, 2024 2:17 PM

One decoder - two engines can work, if the engines have good can motors so you're not overtaxing the decoder with the amount of power needed to run the engines. Plus there's no guarantee that the two engines are going to start, run, and stop exactly the same. With each having it's own decoder, you can adjust the CVs to speed match them. 

Stix
  • Member since
    September 2004
  • From: Dearborn Station
  • 24,281 posts
Posted by richhotrain on Thursday, August 1, 2024 9:38 AM

Sure, a pair of plugs is cheaper, but by how much?

I would (and do) opt for a pair of decoders, as you describe. Lots more flexibility that way, and then you can also run the two locos separately. Otherwise, you have an expensive dummy with that second loco.

Rich

Alton Junction

  • Member since
    September 2002
  • 7,486 posts
One or two decoders?
Posted by ndbprr on Thursday, August 1, 2024 8:14 AM

I like to run two diesels of the same model together. I can do one of two things with decoders. A sound one in one engine and an 8 function in the other. Or I can put one sound decoder in the first engine and send the motor connection by wire to the second engine and the rear headlight for backing instead of hooking up the first rear headlight.  A pair of plugs is cheaper then another decoder.  Thoughts please

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