On Mon, 25 Jun 2007 15:48:38 -0700, "David Farber"
wrote:


"Ross Herbert" wrote in message
.. .
On Fri, 22 Jun 2007 17:47:11 GMT, "James Sweet"
wrote:


wrote in message
roups.com...
On Jun 21, 2:53 pm, "David Farber"
wrote:

Sorry about this incomplete message. It was erroneously sent. I
think the
solution will be to replace the noisy relays with new ones.

That, it would. Stanley makes (made) good stuff, and 28 years
ain't
nohow half-bad. If all it is is relays, count yourself lucky.

Peter Wieck
Wyncote, PA


Might be worth checking to see if there's a diode or rectifier
bridge
in
there. A shorted diode could cause AC to be fed to relay coils
expecting DC
which will make them chatter or buzz.


It could also be due to, or exacerbated by, a dried out
electrolytic
filter capacitor in the DC supply circuitry.

It occurred to me that if I posted the pictures of these relays, that
it
would be easy for somebody that is more familiar with this type of
equipment
would be able to tell me if these relays have AC or DC type coils:

http://www.pbase.com/mrfixit/image/81163240

The contact appears to be in good condition at least.
Can't tell from the text whether it is AC or DC coil. The details
appear to show the contact ratings only. Anything written on the other
side of the coil?


http://www.pbase.com/mrfixit/image/81163242


Midtex 1522T200 - Online Components
http://www.onlinecomponents.com/product/3123033
Appears to be 120V ac coil.


http://www.pbase.com/mrfixit/image/81163244

Midtex 15523Q200 - Online Components
http://www.onlinecomponents.com/product/3123040
Appears to be 24V ac coil

Midtex is now part of the Tyco brand stable but I can't locate the
part numbers on their site. Have requested specifications from Tyco if
available. Will post result.