ZW Whistle Diode Replacement

Kent is the publisher of the Tranz4mr.com site.  He's the best technical and repair expert.  Use either of the diodes he lists.  Leave the white resistor in there.  I took one out and had to order a new one for full function.

12V is too low.  Larger ratings are fine.  The size of that bolt looking assembly is important in a lot of transformers.    A correctly refurbished ZW should activate all whistles and horns on AC trains including electronic engines and whistles.  They won't activate the bell.

Susan,

Thanks so much for your rreply.

Don

I prefer diodes with higher voltage ratings, even though it doesn't seem you need it.  That rating is the reverse voltage rating, and an inductive spike from a coil can generate a spike of hundreds of volts, even though the AC voltage is 18 volts.

Don,

I use the Ruttonsha 16 amp stud diodes.

For what it is worth, I did have "that white wire" tested and it does contain asbestos.  I prefer to remove them.  I haven't had an issue with functionality yet, but to be honest, I only use one tender as a test.  I guess I should go back and test other types of whistles.

On one ZW transformer, I used 24 AWG nichrome wire crimped to 24 AWG copper wire with a cloth covering for the resistance wire.  I haven't noticed a problem yet.  I also have some 20 AWG nichrome wire that I may try.  I am jsut not a fan of that white wire.

I will let you know about testing the transformer with other whistles.

Dennis

Here is my "homemade" resistance wire.  The original resistance wire measures 1.8 ohms, this one measures 1.7 ohms.  I can make it a little longer to match the resistance reading.  It is 24 AWG nichrome wire crimped to 24 AWG copper wire with a cloth covering.  I know they say that the asbestos in that wire is not enough to worry about, but I  can't help it.  If I can avoid it, then I choose to do so.  Any suggestions on the wire would be welcome.

Dennis