Atlas GP39-2 ---- my new favorite locos

[peteski]

Did you get a chance to compare how the wired model runs verses the leaf spring mod?

I would expect both to perform flawlessly when new.  Both designs have been well proven in dozens of different models. Wired-in goes back to the infancy of N scale, and the springy contact design was first used IIRC, on the Kato U30C and many, many locos  from that point on. It is the performance later in the models life that might be different.

To me peronally it is the serviceability, not the performance that I question.  Pickup-spring based model is easier to service, and I also am a strong supported of Victor Miranda's opinion that fewer wires equals better models.

[Ngineer]

but if you haven't tried ESU's motor-only decoders (the LokPilot series), you might be pleasantly surprised at their performance.

John,

thank you very much for your advice! 

Can you please tell me the order number/parts number for an ESU (non-sound) decoder for the new Atlas GP39-2 (and perhaps the new Atlas SD-35) as I am not famliar with ESU decoders.

Until now, I have been using Digitrax command stations and TCS decoders.

   Javier

[peteski]

John,

thank you very much for your advice! 

Can you please tell me the order number/parts number for an ESU (non-sound) decoder for the new Atlas GP39-2 (and perhaps the new Atlas SD-35) as I am not famliar with ESU decoders.

Until now, I have been using Digitrax command stations and TCS decoders.

   Javier

Javier,
One of the links John provided earlier shows the part number of the non-sound decoder.
The link: https://store.sbs4dcc.com/ESU54650LokPilotV4.0DirectMicroOEMNMRADCCDecoderDrop-InforPost-.aspx
Decoder part # 54650
The price of that decoder is comparable to the TCS decoders, and ESU decoder is superior to TCS in motor control, and in configuration in general.

[EmdFan]

I spoke with Atlas and they confirmed that the new chassis will accept the GP38, -2, 40, etc. shells. The fuel tank is interchangeable as are the truck side-frames.

You may run into a lighting issue with that. The new board uses SMLEDs, which don't quite reach the numberboard/headlight glazing part. The older shells were designed for regular LEDs that stuck out from the board. I have a photo somewhere that compares the shells from the inside, I'll see if I can find it.

[EmdFan]

You may run into a lighting issue with that. The new board uses SMLEDs, which don't quite reach the numberboard/headlight glazing part. The older shells were designed for regular LEDs that stuck out from the board. I have a photo somewhere that compares the shells from the inside, I'll see if I can find it.

In this photo the gray shell is the GP39-2, the other two I don't recall exactly, but are either GP38/GP40 or GP38-2/GP40-2. You can see how the GP39-2 glazing is further back in the shell. The chassis photo may be helpful too.

I'm not saying it can't be done, some modification will be in order though.





Steve

[bdennis]

Hmm.. Received my GP39-2 today. Put it on the track.. No sound.. (insert sad face).
Removed the shell and the decoder, checked the contacts for the speaker, lifted them slightly to ensure contact, still no sound. Loco runs but has heaps of momentum (unlike the C-628 I received a few weeks ago). Time to reach for the manual to reset the decoder and do some testing with a spare speaker.

Ran out of time to do any more testing. Back to the RR room tonight to see whats going on.

[jagged ben]

Try F8 to unmute the sound.

[bdennis]

Try F8 to unmute the sound.

Yep been there done that.. Not a F8 issue. No sound at all. No bell no horn not engine. By pressing F8 does not change the issue

Thanks.

[Albersala]

Try to change master volume CV, which I think is CV63. The range should be from 0 to 192. Try to program CV63 with a 192 value and cross your fingers...

[bdennis]

The issue seems to be the speaker.
The decoder is fine and when I place a sugar cube speaker on the output it functions perfectly. ie sound..

Am about to pull the chassis apart to find the fault.
I put the multi meter across the speaker contacts and get an open circuit. I do a bit of wiggling and that resistance changes on the speaker contacts.

From Ron's pictures on page 1 the speaker assembly seems to be part of the motor assembly..

Time for more fault finding.

[spookshow]

I'm pretty sure that the GP39-2 speaker installs the same way as the ones in the IMRC SD40-2. Sprung contacts on the speaker push up against the contacts running down the motor saddle from the decoder contacts up top -



-Mark

[Ed Kapuscinski]

Lol, wouldn't it be funny (and terrible) if the motor contact tab issue was gone only to be replaced by a speaker tab issue?

Also, these look good. I'm sad to see they used the same grills from the GP38-2 that, in my opinion, aren't nearly as nice as the ones on their GP40. But I wouldn't throw them out of bed for eating crackers.

Now to bottom feed and slowly grab a few in D&H. After all, I've been neglecting that aspect of the NCR for far too long.

[u18b]

Something occurred to me that may seem wild and crazy.... 

But ..... one of my concerns with going to those wires would be that it is inevitable that one day they will break (assuming the loco is actually run).

I've already shown that the old Phosphor bronze strips on the side will work with this loco....

Point- so if anyone wanted to, you could use BOTH means of pickup.

The jumper wires are soldered to a point OUTSIDE the middle.


So there should be no obstruction problem as shown here.



So from that photo above, the strips only need to be bent down to make contact.

I don't know that many people will do this... but I probably will.  The strips are cheap.

I know that someone here might accuse me of using overkill..... but it wouldn't be the first time.    

(nor probably the last)

[bdennis]

Problem fixed...
The speaker is like the IMRC SD40-2. There are contacts.

I think one of the spring contacts on the speaker was not in its slot correctly and was not enabled to spring and make contact with the plate under the motor.
The trick is in reassembly. I disassembled the chassis, then checked everything then left the speaker out, reassembled the chassis with the trucks installed. Then pushed the speaker into place. There are lugs on either end that are tapered (1 way). So it clicks into place. Once I fixed the problem contact and enabled it to move, then reassembled and put the speaker into place... Put on the track.. Yay. I have sound. All fixed.

Thanks for the info.

I have taken a few pictures so will upload and share.. ASAP.

[Santa Fe Guy]

Good result Brendan, pity is you had to do it at all.
Big John has had pick up wiring issue with his on one of the trucks so 2 from 2 is not good IMO.
Rod.