New Run of Athearn Challengers, Surprise!

[Nato]

                 :|After being out of town for four days on an Astronomy Trip, I was able to get to the PO today to retrieve my mail including my NP Challenger. Athearn has done their homework on these except for SP&S oil locos which appear to use the modern UP Excursion Oil Bunker Insert. Detail right down to the NP white running board striping, and white wall striping on drivers and wheels. I have no issues (mech binding etc.) with mine straight out of the box on my DC layout with wireless CVP system, I get a nice slow start, steam sounds, directional headlight and backup light. When stopping in DC the locomotive does come to an abrupt stop. I can' t wait to run it in full DCC on the Wasatch N Scale layout at the November "Wasatch Rails" train show in Sandy / Salt Lake , Utah. Nate Goodman (Nato).  Thanks Chuck at FRT for testing these locomotives before shipping.

[nkalanaga]

Bob:  No, I don't run the layout using parts from Goodwill!  I use the one part from Goodwill as an AC transformer to power my MRC handheld throttle, and a source of variable DC for testing and wheel cleaning.  I haven't used a rheostat throttle since I bought a Troller handheld throttle back when they were new.  In fact, I used that Lionel pack to run it, since it's rated for 1.5 amps, on the AC, and my throttles are only rated for 1 amp.

Max:  It isn't the voltage drop.  It ran fine with the Lionel powerpack hooked up to the same layout wiring as the usual MRC throttle, and with the loco at the same location on the layout, quite close to the throttle connection.  Judging from the speed at which other locos run there, the drop is minimal.  The large drop is at the other end of the layout, and could easily be fixed with larger wire.  Since it isn't a problem, I haven't bothered, and it does protect the Nn3 from high voltages.  The standard gauge is speed restricted on the dual gauge track anyway, so it doesn't need more than 9 or 10 volts.

As for switching to DCC, I'd be willing, except that I certainly can't afford it.  If necessary, I can rewire diesels to run on DC.  It may not be pretty, but wouldn't be that hard.  Fortunately there aren't many diesels I need to fill my roster.  I'm not about to take the Challenger apart.

[C62-2]

What does the MRC output? I have a challenger from a previous run, and it never worked well when I was trying to run it with an MRC DC powerpack. It runs beautifully when I run it with a Kato DC powerpack, so the problem seems to be with MRC's flavor of DC. In the end, though, I bought a kato/digitrax zephyr DCC controller, and switch back and forth between that and the kato DC controller, depending on what I'm running at the moment.

[nkalanaga]

I have no idea what the waveform is, just that it says "12.5V".  The Lionel is plain old full-wave DC, straight from the rectifier.  This weekend I'll try running it, in the box, using the MRC.  Didn't think to do that while I had it disconnected from the layout.  Since the manual says not to exceed 21(?) volts, I might just buy a cheap G scale powerpack, if there is such a thing.

More likely I won't run it at all.  I really don't need a steam loco on my standard gauge, and VERY seldom run the ones I have, so this was bought more "because it is SP&S" than because I had a use for it.  It can join my CC/Kato GN S2 in the closet.

[mmagliaro]

I have no idea what the waveform is, just that it says "12.5V".  The Lionel is plain old full-wave DC, straight from the rectifier.  This weekend I'll try running it, in the box, using the MRC.  Didn't think to do that while I had it disconnected from the layout.  Since the manual says not to exceed 21(?) volts, I might just buy a cheap G scale powerpack, if there is such a thing.

More likely I won't run it at all.  I really don't need a steam loco on my standard gauge, and VERY seldom run the ones I have, so this was bought more "because it is SP&S" than because I had a use for it.  It can join my CC/Kato GN S2 in the closet.

I just reread your descriptions of your problem, and now I get it.  So it only fails to work if that MRC hand-held is in there, in between the Lionel source and the engine.   I didn't think there was much inside those old MRC hand-held things, but does it have a typical heavy pulse like some of the MRC tech power packs had (like the 2500?).  Do your engines growl when starting up and running at low speed?   Heavy pulses do confuse decoders and could be the whole source of your woes.  You could try slapping a big electrolytic cap across the outputs of that 55 (being careful of the polarity, of course) and see if the Challenger will work.  That would point to pulses from the 55 surely being the problem.

[peteski]

I just reread your descriptions of your problem, and now I get it.  So it only fails to work if that MRC hand-held is in there, in between the Lionel source and the engine.   I didn't think there was much inside those old MRC hand-held things, but does it have a typical heavy pulse like some of the MRC tech power packs had (like the 2500?).  Do your engines growl when starting up and running at low speed?   Heavy pulses do confuse decoders and could be the whole source of your woes.  You could try slapping a big electrolytic cap across the outputs of that 55 (being careful of the polarity, of course) and see if the Challenger will work.  That would point to pulses from the 55 surely being the problem.

Maybe the pulses are his problem, but it is more likely due that they do not result in enough voltage inside the decoder for it to decide that the voltage is high enough to start driving the motor. Why? Because the sound part works just  fine.  If the pulses were messing the decoder up, wouldn't the sound also act squirrely (a highly technical term)?   But either way, the result is a non-running loco.

[mmagliaro]

Maybe the pulses are his problem, but it is more likely due that they do not result in enough voltage inside the decoder for it to decide that the voltage is high enough to start driving the motor. Why? Because the sound part works just  fine.  If the pulses were messing the decoder up, wouldn't the sound also act squirrely (a highly technical term)?   But either way, the result is a non-running loco.

Good point.  Although he says the drop is minimal, maybe it's just enough to keep from getting over the decoder's turn-on threshold.
It would help to have some actual measued voltages on the track where the engine runs and at the other place on the layout where it doesn't.

[nkalanaga]

I'm with Peteski, and think that the problem is simply that the MRC doesn't put out enough voltage.  The MRC calls for "16 to 22 Volt AC" input, and the Lionel puts out 16 volts, which is the minimum required.  It's entirely possible that the MRC's output is actually less than 12.5V, and the decoder can't power the motor. 

The Lionel, on the other hand, almost certainly produces a solid 14V, and the loco ran fine on it, at the same location where it wouldn't move on the MRC.  Any voltage drop in the wiring should be minimal there, unlike at the other end of the layout, where I tried it first. 

If it had worked in the second location, replacing the main power feed would have been easy, and would have solved the entire problem.  The layout has block feeders for multi-cab control, but is currently wired for one throttle, so there are only two wires running the length of it.  After all, it's just me, and I can only run one train at a time!

[nkalanaga]

OK, I took the wires loose again, and did some testing.  Using the MRC throttle, connected directly to the tender wheels with 12 gauge copper wire, the wheels started turning at about 80% throttle.  No voltmeter, but the throttle seems to have a linear pot, and is marked 0-100.  The manual says it should start at 7.5 volts, so apparently the throttle only puts out about 10V, as I suspected in the last post.  I didn't retry it on the track, with the MRC, as there didn't seem to be any point in that.

I then connected the Lionel powerpack to the layout feeder, and tried the loco at the far end, where the voltage drop is greatest.  It ran slowly, but did run, and had some speed range.  In fact, at full throttle, it looked about right for my layout, which isn't a high speed mainline.  As before, it ran faster closer to the powerpack connections.  I already knew I had a significant voltage drop from one end to the other.

It did have "issues" with dirty track, and seems to require almost perfect contact, as the sound dropped out at every glitch, and several times it stopped and restarted, but I've heard that is common with sound decoders.  If so, I won't consider that a fault of the loco.

So, it appears that all I need is more voltage!  But since my diesels, and old MRC Mallet, run fine on what I have, there's no hurry.  Besides, the cats still don't like the noise, and it's too loud for my liking as well.  It does sound good, though.

[Nato]

                   :|Here are three NP Challenger photos taken by Bob Gilmore on his phone. "Thanks!"  Nate Goodman @Nato 
(Yes, my old Samsung Galaxy S5 using "Selective Focus")

[nkalanaga]

It's a beautiful model, and in spite of the size, and number of wheels, is easier to put on the track than my Kato electrics.  But it is definitely intended for DCC layouts. 

[robert3985]

By the way, Nate's NP Challenger runs great on his DC-only layout, and the sound is pretty good too.  I noticed the brake squeal when Nate was bringing it to a slow stop and the chuff through Riverside.  I'm not sure what a NP Challenger's whistle is supposed to sound like, but this one is definitely different than the UP Challenger's stock whistle.

Although it encountered a stop through the Kelly Canyon tunnel...right in the middle of the tunnel of course, this is caused by inaccessibility of that track and the extraordinary measures needed to clean it, which hasn't been done in a long time.  Everywhere else on Nate's layout, it ran smoothly, didn't derail, the sound never stopped and started back up, and there was plenty of speed out on the mainline with Nate's wireless throttle at or slightly less than 3/4 throttle.

We didn't put any cars behind it, so I can't say how it pulls, but on Nate's zero-grade layout, I'm sure it'll be sufficient.

One problem with the engine we noticed after we took a set of photos and put them up on Nate's desktop screen was that the numberboards on the smokebox were really out of kilter.  This was caused by them being inserted too deep and at too steep an angle when the model was assembled at the factory, so that their fronts hit the top of the curvature of the smokebox cylinder shape.  I gently (but firmly) pulled them out just a bit, and rotated them outward.  Then I did fine adjustments on them by pressing gently (but firmly) on their fronts so that from the side, they were parallel to the line of the top of the smokebox.  They are glued in, but by gently (but firmly) pulling on them and gently twisting them, the adhesive bond will be broken and you can adjust them.  Luckily, the friction fit is still firm after the adhesive bond is broken.

After the numberboards were straightened, we re-took the photos.

On my layout, with its tight-NMRA clearanced, hand-laid turnouts...I have to re-gauge my Athearn Challengers and Big Boys so they don't "hop" through the turnout frogs, but on Nate's with his code 80 Peco turnouts, it runs without a hitch.  To be fair, the only engines I haven't had to re-gauge are my Kato FEF's, each of which have been EXACTLY properly gauged out of the box.

Anyway, I was favorably impressed with this fine-looking, and fine-running model, and Athearn should be congratulated on taking the time and effort to reproduce the NP Challenger in addition to the UP version.

Now, if they'd do an early Challenger next, then a DRG&W Challenger...that'd be a perfect use of the model's chassis and the world would be a better place!

Cheerio!
Bob Gilmore

[mmagliaro]

It's a beautiful model, and in spite of the size, and number of wheels, is easier to put on the track than my Kato electrics.  But it is definitely intended for DCC layouts.

If you want it to be a straight DC engine...
I had a first-run Challenger here for repairs once, and in order to properly run it and diagnose it, I bypassed the decoder in the tender.
I removed the decoder (unplugged it from the socket) and jumpered pins 1-2 together and 4-5 together on the 5-pin socket in the tender.   I just used short lengths of solid (not stranded) wire.  I cannot remember what gauge fit the socket holes well.

It will be a straight DC engine after that,  *** ASSUMING they have not changed the wiring arrangement since the first run. ***
Of course, you give up the sound if you do this.

This also does not damage or otherwise permanently disable the decoder.  Any time you want, you can remove the jumper wires and plug the decoder back in.

[Chris333]

It will be a straight DC engine after that

[narrowminded]

On my layout, with its tight-NMRA clearanced, hand-laid turnouts...I have to re-gauge my Athearn Challengers and Big Boys so they don't "hop" through the turnout frogs, but on Nate's with his code 80 Peco turnouts, it runs without a hitch.  To be fair, the only engines I haven't had to re-gauge are my Kato FEF's, each of which have been EXACTLY properly gauged out of the box.

Cheerio!
Bob Gilmore

Not to derail, do you have a specific number you use for wheel back spacings?  The NMRA standards allow .297"/ .303".