Hello all, I just purchased a second hand Chromegatrol and find that although it functions properly, it emits a fairly loud hum when the Expose or Print switches are thrown. I have not used a Chromegatrol before and wonder if the humming is normal. I have been using an old Omega timer that does not hum. Thanks for your help.
Might want to check that the bolts holding the transformer down are tight and any rubber vibration washers/spacers are intact but other than that, as said, large transformers tend to vibrate & hum when under heavy load.
Bob's correct and you might also want to check the bolts/screws that hold the transformer laminations together. Sometimes the hum will loosen this hardware but they are usually secured with Pliobond/varnish to prevent this from happening.
Thanks everyone for posting replies. The humming does not sound as if something is loose, just the transformer vibrating. I am glad to hear this is normal. I will listen for any change that indicates something has come loose inside. Although second hand the unit does not appear to have seen heavy use. It is the later model, all in black.
Indeed, B flat is 58.27 hertz, so if you have 60 cycle AC, it will indeed be a little sharp. Wow, never guessed someone would pick up on that one ;-)
Just a funny little story...a friend of mine once worked with a singer who said he wanted to sing a particluar song in the key of "B, little b"...honest to God truth!