Digitrax DN163K4A

[keeper]

According to Digitrax decoder selector, the Digitrax DN163K4A will fit into the Kato ALC-42 Charger.
Does someone know it the DN163K4B might fit as well? From the dimensions they are identical.
I'm asking because I could get the B but not the A at the moment.

 

[C855B]

Streamlined Backshop has the 'A' variant in stock: https://store.sbs4dcc.com/DigitraxDN163K4ADCCDecoder.aspx

But for discussion's sake, here are images of both. Poor resolution on the 'B' is Digitrax's image:





I can see a couple of minor differences in components, the one that gives me slight pause about spec differences is the two capacitors on the 'A' to the right of the motor section versus one bigger cap on the 'B'. But - more importantly, I think - is that Digitrax currently catalogs both, each spec'd for different Kato models. If it were me I'd just go ahead and order the 'A' since I can get it from a reputable source.

[peteski]

The size of the solder pads for "that" capacitor looks to be identical.  Those pads look like it might have been designed for a single tantalum cap.  But on the "A" variant there are 2 smaller multilayer ceramic caps while on the "B" there is a single, larger size multilayer ceramic cap.  I suspect that the total capacitance of those 2 caps is the same as the single larger cap.   Just thinking out loud. . .

The other difference is that the "B" variant doesn't seem to have a headlight LED populated on the right side of the decoder.  It seems to be for a locomotive which only has a forward headlight.

[keeper]

Hm, the 'A' is for the FEF3 and Glacier Express whereas the 'B' is for the MP36PH.

[reinhardtjh]

I just got my ALC-42 sets Friday. I haven't been able to get the shell off yet to see what fits.  Kato did a really good job on fitting the shell to the base.  I can get it to spread some but so far I haven't found the right amount to get it free.

[peteski]

I just got my ALC-42 sets Friday. I haven't been able to get the shell off yet to see what fits.  Kato did a really good job on fitting the shell to the base.  I can get it to spread some but so far I haven't found the right amount to get it free.

Kelley shows one apart in his video in https://www.therailwire.net/forum/index.php?topic=55200.0
From what I can see, it uses standard Kato method of having 2 latches diagonally across.  Looking at the bottom of the loco with the rear towards you, one latch is on the right front side, and 2nd latch is on the left rear side.

You should be able to stick 2 sharp toothpicks in the latch areas between the metal chassis part of the latch and the clear window part of the latch to spread them apart. Once unlocked, you should be able to separate the shell from the chassis.

Sort of like in a Kato E-unit. See few photos in my gallery.

[reinhardtjh]

Thanks @peteski  Your description and gallery pictures did the trick

[reinhardtjh]

According to Digitrax decoder selector, the Digitrax DN163K4A will fit into the Kato ALC-42 Charger.
Does someone know it the DN163K4B might fit as well? From the dimensions they are identical.
I'm asking because I could get the B but not the A at the moment.

 

With Peteski's help I got the shell off my ALC-42.  The form factor of the two decoders looks reasonable for fitting but I'm wondering about the fron LED.  It looks like the Digitrax board has it too far forward to match up with the internal light pipe on the shell.  The Kato DC board has the LED farther back from the front of the board about where that middle surface mount chip is on the Digitrax board.

[sundowner]

A has light on both ends

B has lights on the front and it turns red when the loco is going in reverse

[keeper]

Thanks for all the info and your time. A few days ago, the A has become available again. So problem solved.