Convert New K4 to DC

[BoyREB]

I have a new PRR K4 that I'd like to convert to straight DC (for the time being) by removing the DCC board and replacing it with a blanking plug.  Does anyone know where I can get one to fit.  I'd rather not solder jumper wires to the main board.  I know this engine should run OK with DC but I have a MRC Tech 3 Model 9000 power pack and the on-board DCC doesn't like the TAT IV throttle pulses.  Thanks.
Bob.

[gatrhumpy]

If Bachmann doesn't have the jumper plugs, you'll have to solder ones yourself.

[BoyREB]

I'm willing to do that, but what kind of plug do I need and where can I get it?

[BoyREB]

I have some new input on this topic.  I received a suggestion that I try a different throttle.  I have a Bachmann Acela set that came with a Bachmann DC throttle that was never used. I took it out of it's original packaging and swapped out my MRC throttle and guess what.  As soon as I plugged in the power pack my K4 took off at about 200 miles an hour.  The position of the speed control was set at zero and the direction switch made no difference.  As soon as it was plugged in the engine took off always in the same direction.  I then put the Acela power car on my test oval and it did exactly the same thing as did my HHP-8.  All three engines did the same thing.  The Bachmann DC throttle must be bad I guess.  No joy in Mudville today.  The K4 looks pretty in my display cabinet though.   

[brokemoto]

You might try going to Fee Pay and buying a DC power pack there.   The MRC 1300, 1370, and 1400 are all good, inexpensive power packs.   If you can find a 2400, it has an ON-OFF pulse switch, so that you can run it on straight DC (or as "straight" as rectified DC can be).   The 2800, which is a  dual-control, is allright, as well.   The 1300 and 1370 have a discreet pulse, so the B-mann locomotives with factory DCC will operate acceptably on them.  I have no experience with the 1400.  The Bachmann locomotives with factory DCC will operate acceptably on the 2800 as well as the 2400, pulse ON or OFF, on the latter.

Most of the Bachpersonn locomotives with factory DCC will operate acceptably on the 2500, but I have seen some do some funny things on it.  The 2500 has a stronger pulse than does the others.

B-mann used to sell DC power packs under its SPECTRUM line that had built-in pulse that you could not turn off, but it appears that they have discontinued those power supplies.  The only experience that I had with any of those was one hobby store that had one as its test track power supply.  It seemed to be allright, although when operating a locomotive on a test track, the only thing that you are trying to learn is if it does run.  B-mann does sell the trainset power pack, but, while it is certainly better than most trainset power packs of the past, it is not the best.  I do have experience with it.

Kato sells a power pack that is set up similar to B-mann's power pack.  It has no pulse.  I am somewhat less-than-impressed with it, as well.

If there is an upcoming show in your area, you might try there and see if you can get a good price on an MRC.  I would pay no more than twenty dollars for a used one--and it would have to be a really good used power supply.  New, they can go for anything from twenty-five to fifty-five dollars.

[RGW]

I run Dual mode DCC locos on my Dc layout with no problem  Y3 with sound,Bachmann 2-10-2,2-6-0,4-6-0. I use MRC control master 20 ? forget the name.and other MRC tech2s with pulse off buttons and have used the Kato and bachmann controlers with no problems.

One thing to note sound equipped take more valtage to start. My walthers Y3s do start up( begin sound.lights) until about 7 volts and will not move until the voltage is a little higher yet. 

[richardl]

I'm willing to do that, but what kind of plug do I need and where can I get it?

A different throttle would be the way to go but here is a 4-6-0 decoder to give you an idea of what is needed to convert to DC. Your loco probably has a different decoder setup.

http://www.bachmanntrains.com/home-usa/dwg/dwgs/N_BALDWIN_4-6-0_EXPLODE_DRAWING_N514X_(1).pdf

Bachmann has a bad habit of pulling diagrams from their site. Really wish they would not do that.
I checked HO Seeker for Bachmann but that site only has HO scale.

Rich

[gatrhumpy]

Why not get a cheap DCC system like Bachmann's?

[BoyREB]

Thanks for all the replies.  Still didn't the info on the blanking plug I need though.  I did mention that I was using the MRC throttle on my TEST oval.  What I didn't mention is that my layout has 48 blocks and 32 Oak Tree Systems RCI throttles with feedback and block occupancy detectors.  Each engine has a profile with horsepower, speed profiles, fuel supply, etc.  have a complete working signal system that controls the block speeds and over 300 points of digital output controlling lights and sound effects.  All of which are managed by Railroad & Company Train Controller software running on my computer.  I would have to give up much of that up in order to get that one engine to work.  I think that the price performance aspect wouldn't make sense.  One other thing, what about my other 26 steam locomotives (many of which are Key Imports brass). Several of my engines have been fine tuned by the Starmans brothers.  Their work is truly amazing and when they're done an engine runs like a fine Swiss watch.  Also what about my 62 other deisel engines and 17 Electric locomotives? All of which would have to be converted to DCC.  I wonder what that would cost.  All I really want is the info on the blank plug I can order from Digi-Key once I know the pin spacing. I'd rather not take my engine's tender apart to measure the pins without having the plug on-hand. I guess I'll try to talk to a technician at Bachmann they may know what I need to order. Thanks again for the suggestions. 

[Mike C]

 If the K4 is anything like the Berk , all the electronics are pretty much hard wired into the tender . There isn't any plug . The only way will be to rewire the whole tender , I think .  I don't have one yet , and the Spookshow.net review hasn't been posted yet , so I'm making an educated guess here .  Mark at Spookshow.net should have his review posted in a day or so though .

[spookshow]

The tender is set up exactly like the Berk (sound decoder plugged into a parallel 9-pin connector on top of the tender PC board). As for what sort of "dummy/jumper" plug you'd use to run without a decoder (or if such a thing even exists), I have no idea . There isn't anything in the instructions about running without a decoder.



Cheers,
-Mark

[BoyREB]

Thanks for the picture Mark.  I was hoping the DCC decoder was "plugged" in to the main board and not soldered in as indicated by a previous post.  The wiring diagram that came with the engine indicates which wires I need to run to power the motor and lights once the decoder is removed.  (Yes of course I'll make sure there is a current limiting resistor to protect the headlight  LED) so I'm getting closer.  It's obvious that the commonly used 0.100" perfboard spacing pin plug won't work - too big.  I'll take the tender shell off today and measure the pin spacing.       

[BoyREB]

Mark. One more thing.  I removed the two small screws just behind the front tender truck and the front of the tender shell is now loose but the rear of the shell still seems attached.  The truck bolster screws don't look like they are the problem and the coupler is still attached in your picture so it can't be that screw. I don't want to force things and I don't see any other screws.  What next? 

[spookshow]

All I did was remove the two screws you mentioned and the shell came right off.

FYI, here's what the decoder connects to -



Unfortunately, the Digitrax DHDP dummy plug is also a male (pinned) connection, so it wouldn't work here. If there's such a thing as a 9-pin wiring harness with two female ends, you could use that to connect the dummy plug to the tender PC board. But absent that, it looks like a solder job.

Cheers,
-Mark

[spookshow]

Correction on removing the tender shell - turns out there are a couple of clips on the back end of the shell that hook into the chassis. So, lift the front of the shell up first and then wiggle the clips loose. I guess I must've done this accidentally when I removed the shell since I didn't even notice the clips until putting the shell back on.

Cheers,
-Mark