The 1N5401 diode is still a common part. Radio Shack may still have them? It is rated at 100v as C.W stated. The higher the last number the higher the voltage 1=100v, 2=200v, etc. They are all the same amperage, 3 amps. You could use a IN5401 or up as they are all higher voltage. Usually not a good idea to go to a lower voltage.
I would send you one, but all I have is 1N5400's which are only 50v. For model trains stuff I think this would more than adequate, but as I said it is usually not a good idea to use lesser rated components for replacements. If one of the electronics guys like GRJ or stan2004 see this and advise the 50v is ok, I would be happy to send you one.
Otherwise, here is one from Digi-Key: http://www.digikey.com/product...N5401FSCT-ND/1532774
They have low shipping rates on small orders if you use USPS First Class, and they ship very fast. Would be nice if you had something else to order with it though, like some bridge rectifiers, resistors, LEDs or something you might happen to be needing. Good to have some extra parts on hand sometimes.
Keep track of the silver band end and where is was connected, it needs to go back the same way or it won't work.
