Transformer hum question

[Birds]

Sorry if this is a basic question. I searched the archives and didn't find anything.

I recently pulled my KW transformer out after having it stored for over 10 years. It hums. Is this is normal for these units.

It was given to me as a gift and shortly after all the trains had to go it into storage, so I can't say what it was like a while back.

Thanks,
Birds

[pbjwilson]

Yep. Most if not all transformers hum. The older postwar models probably more so than modern ones. Your KW is doin what its 'sposed to do.

[msacco]

FYI. There was a recent discussion on this very topic pertaining to ZWs on the OGR Forum. From what I remember it has something to do with the laminations becoming loose. Search the archives under ZW hum

Mike S.

[lionelsoni]

The type Z has screws threaded through its cast frame that are used to compress the laminations to minimize the hum. I haven't seen this on any other transformers; but I've never seen the insides of a KW either.

[Chris F]

Here's the link for the thread to which Mike refered:

http://ogaugerr.infopop.cc/groupee/forums/a/tpc/f/57660482/m/1441058153

And here's a link to information from Lionel's service manual:

http://pictures.olsenstoy.com/searchcd31.htm?itm=657

Repair work on a transformer is somewhat tricky, even for those who have been in the hobby for a while. Consider letting it hum unless it becomes annoyingly loud (or learns the words [:D] ). If the KW is serviced, the whistle rectifier should be replaced with a diode.

[Birds]

Thank you all for your replies and for all the links!

I'll just enjoy it and run the trains.

Thank you again.

Birds

[Anonymous]

What is it humming? I have 2 CW's...one hums "Camptown Races", the other hums "Sweet Georgia Brown"...which brings me to 2 questions: First, should'nt new transformers hum "current" tunes? Second, is there any way I can get them to hum the same tune? My KW hums what sounds like rap music, so I don't use it. Thanks for your help. Joe

[Anonymous]

Humming is when you don't know the words. (sorry couldn't resist)

[4kitties]

Birds,

I have never heard a toy train transformer that didn't hum at least a little. Some are louder than others. There were 2 kinds of cores or "stacks" used in the KW's. One type is riveted together and is noticeably quieter than the other type. I am not sure how loud a KW with a non-riveted stack should be, but both of my Kw's have riveted stacks and their hum is negligible. If your KW hums loudly, it may have the minor problem that one of mine had: the metal chassis or frame has "ears" that are meant to push against the sides of the stack and hold it firmly in place. Mine were loose, allowing the stack to buzz and radiate that noise up into the throttle handles. Bending the ears inward slightly so that the stack is gripped firmly took care of the excess noise.

If your KW has a non-riveted stack and the hum is originating from within the stack, then you will need to apply the technique given in the OGR forum thread. Good luck.

Joel