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KA4 for Paragon 2 decoder

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  • Member since
    March, 2017
  • 2 posts
KA4 for Paragon 2 decoder
Posted by DylanS on Thursday, March 02, 2017 9:40 PM


I'm somewhat new to DCC and decoders, with a very basic electrical backround. I purchased a EMD SW1500 with a paragon 2 decoder installed, and I have been having some troubles with low speeds around some turnouts that have powered frogs and have clean rails. I was intereseted in purchasing a KA4 Keep Alive Cap. and would like to install it however I'm not sure where to install it. Not sure how to upload a picture on here, I'm new, but if anyone knows what the paragon 2 decoder looks like it would be helpful to know where to put the wires for the Cap.

Easy Simplistic replies would be appreciated.




Paragon 2

  • Member since
    March, 2017
  • 2 posts
Posted by DylanS on Sunday, May 14, 2017 11:52 AM

 OK, I'm gonna try to revitalize this topic. I contacted broadway limited and this is what they stated. They did give me a brief description of some of the pins which was for a different model but I could follow along and make an educated guess as to which pin was what.

Broadway:  “Our Paragon2 decoders come equipped with a capacitor to keep the engine 
going during a very brief interruption in power, is the engine having a
problem while going over a frog or a switch?
The reason I ask is because you may not need to install a Keep Alive if
there is something going on with that engine like a pickup issue - if
that is the case we can definitely assist you.

We do not support upgrades/modifications here in the service bay, and we
do not have any experience with installing a Keep Alive on our decoders.

Because of this, I do not know where or how you would hook up the wires
for something like that.
Please be advised that any malfunction of the decoder due to
installation of a Keep Alive is not covered under warranty.

Pin outs can vary based on what is programmed into the decoder.
JPGM: Serial wire (usually used for chuff on a steam engine and/or

J1: Pin1 = Front Light
J1: Pin2 = Front Light
J1: Pin3 = Rear Light
J1: Pin4 = Rear Light

J2: Pin1 = Speaker +
J2: Pin2 = Speaker -

J3: Pin1 = Track +
J3: Pin2 = Track -
J3: Pin3 = Motor +
J3: Pin4 = Motor -

J4: Pin1 Track +
J4: Pin2 Track -

J5: Pin1 Track +
J5: Pin2 Track -

J8: Pin1 Mars Light/3.3V
J8: Pin2 Mars Light/Serial
J8: Pin3 Cab Light
J8: Pin4 Cab Light
J8: Pin5 Wheel Sensor”
Now I did send it into Broadway to get looked at and they cleaned and inspected everything. After I got the engine back I took it to a model train shop while I was on a trip, and he cleaned the wheels and ran it on his set with dead frogs and it actually worked pretty good, only one small hiccup. However I’m still interested in installing the Keep Alive to prevent any hiccups of any kind. So he opened it and examined it, he usually has someone else do modifications to engines but he knew a great deal. He couldn’t find any capacitor as stated by Broadway but he said he would wire the KA4 to one of the two pickups in parallel that feed to the board. I’m thinking either the J3 or J4 pin wires. My question is does this sound right to you? I want to hear some opinions before I pull the trigger on this. Thanks.

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