DN163K1B vs DN163K1C

[Herc Driver]

Hi Guys,

I just picked up the new Kato SD70ACe and have a small problem/question. Some websites indicate the correct decoder to use is the K1B while others claim the K1C should be used. Does any knowledgeable DCC guru's know which would be better to use? They measure out to be identical (according to Digitrax) but even Digitrax doesn't specifically indicate which decoder is better for that engine. Any ideas?

Thanks

[doctorwayne]

I'm just a DC operator, but stumbled across your question and was intrigued. According to the Digitrax website, the K1B is rated at 1.5 amps/2.0 amps peak, while the K1C is rated at 1 amp/1.25amps peak. I don't know enough about DCC to comment on whether or not there are any other differences, but it would seem to me that the K1B would be more robust in service.

This is where I got the info Digitrax Decoder Selection Guide, but you need to click on the "Instructions" for the ratings, which are not the same as the numbers shown in the Product Listings.

Wayne

[Herc Driver]

Update.....

I tried installing the K1B and it didn't fit well. The rear portion of the decoder comes in contact with two plastic attachment points located near the top, inside, rear of the shell. Possibly like the suggested installation of this same decoder in an AC4400 that requires the exhaust vent attachment points filed down, maybe this decoder will still fit if I file some plastic off the exhaust vent attachment points that now interfere. I'm really hoping this will work since I have three more of these engines and the same decoders on order. Hopefully, I can figure out a solution and still keep my LHS order intact and on track for delivery.

[Herc Driver]

Thanks Wayne for the info.

I noticed that too, but I'm not as well versed in DCC to know if that's a big player or not. In all other ways, the decoder fit well. There's just some interference to deal with at the rear portion of the shell.

Unfortunately, I've noticed that Digitrax is not the best at maintaining a "total" listing of exactly which decoders will fit into exactly which engine. Some of these plug-n-play decoders fit many different models, but I guess there's some trimming to be done to make that happen successfully.

Thanks again!

[Herc Driver]

My apologies to all who stopped by to read and wonder about this...I just visited the Kato website and they discuss this very problem and have suggested the same solution I came up with. The attachment pins that interfere need to be shaved down about 1/16th an inch to allow the decoder to fit correctly. So tomorrow, that's what I'll try to do.

But you bring up an interesting question about the slight electrical differences between the two decoders. The engines seem to have exactly the same motors installed, with the same style of electrical pickups and frame size/weight as the AC4400...so you'd think this decoder would work fine in an SD70. (Famous last words.....)

(Once again.. ...foiled by failure to read all the available directions. Aaarrrgghhh. )

[MasonJar]

Another alternative is to look beyond Digitrax at other manufacturers. There may even be a drop in circuit board type for Kato locos?

Andrew

[Herc Driver]

You're so right...I'm starting to look at TCS and MRC. I have a contact here in Charlotte that's a TCS installer/dealer and I've already added two Sound MRC decoders that seem to work well in a Kato SD80MAC and AC4400. My only complaint about the MRC decoders is the lighting is very dim. Even when I set the CV value to the highest setting, it's very dim. I don't think the "generic" decoder board has the bulb length needed to properly illuminate the number boards and head/rear lights. I might try adding a small pipe of clear plastic to transmit the light from the bulb to the headlight a bit better. I also wish the MRC Sound decoder had four or five volume settings. Sometimes it's great to turn it up, but sometimes you need it very quiet.

I consider myself a novice at installing and choosing decoders. As long as the manufacturer recommends a certain model, I'll try it. But I don't have the knowledge yet to pick and choose which decoder would be the best based on electrical needs of a particular engine. Maybe I'm making more of this than needs be since we're talking about such a small power draw, but I'd like to choose the best one I could for each application.

Thanks again!

[upnick]

Hi Herc,

I would stick with the Digitrax K1 B decoder if i were you and trim the exhaust vents tabs ......... i had to do this on an install with the AC4400 from Kato to get a good fit of the body initially with a curved file in the body but i wore the vent tabs so thin the exhaust came off and ended up trimming the ends with a knife and glued it in place.

As far as MRC decoders and their settings they arent as good as Digitrax in the CV range of settings as i know with a sound decoder in one of the locos the volume control is not good and hardly a difference in settings can be detected.

The Digitrax in yard mode are exceptional performers if this is what you want.

[Herc Driver]

Quick update again....

I made the K1B fit...it was quite simple. All you need to do is follow the disassembly instructions on the Kato website about this particular decoder installation, and install the K1B decoder. But, before reattaching the shell, file both front and rear light bulbs flat and inline with the top of the frame. Also, snip off about 1/16" of the plastic that transmits the light from the bulb to the ditch lights. That was it! I should have purchased the right decoder as Kato suggested, but unfortunately, that information was posted by Kato long after I ordered the engines and wrong decoders. The only difference...the K1C decoder has a tiny LED light if I remember correctly while the K1B has a small "rice" light bulb. Once you remove any material inside the SD70 shell that interferes with the larger light bulbs - the decoder fits fine.

(I'd return the decoders I've ordered, but my LHS owner called today and said they arrived in the store...and there's really no returning anything. Go figure.)