Model Railway Forum

Am I correct in thinking that theoretically a keep-alive capacitor can be retrofitted to any decoder?

I believe so.

If you're good at soldering wires to a tiny Surface Mount PCB, then yes.

So it doesn’t go across the pickup terminals?

No, has to be connected to the output side of the bridge rectifier. The input side of the bridge rectifier goes to the pickups.

How they connect also depends on how the decoder is designed, some just need a capacitor as all the other needed components are already built into the decoders design but some need a few extra components for current limiting etc

Not all decoders from the same maker are the same either, I use Zimo and all their small decoders like their MX617 & MX616 need the extra components, I use the prebuilt Lifelink sold by Youchoos but their MX633 etc only need a capacitor added

I have just been fitting Stay Alive via the LifeLink to all the MX616 decoders I have on my N-Gauge 0-6-0 shunting locos and its made quite a difference to the running qualities especially over the insulfrog setrack points on my shunting layout

LifeLink next to the MX616 for size comparis