[Boatanchors] 51J4 Muting 12v PS?

[Eugene Hertz]

Hi All,

setting up my 51J4 to mute from my antenna changeover relay.  I was looking thru my junk box for a 12V wall wart to power the 51J4 relay and found something interesting that I can't explain...

Seems I have a bunch of these wallwarts that are labeled for 12VDC output. I noticed that some output 12VDC such as an old laptop wallwart. However, some others that are labeled as 12VDC actually output something like 20VDC when I measure it with my dmm. One example is a wallwart for a cordless phone. It is very small and the output says 12vdc 200ma.  It measures 20vdc on the dmm.  Why would this be? I get the same result on a couple of these wallwarts, so I don't think its a fluke. 

Could it be because the wallwart is somehow expecting some loading? If I loaded this would it output 12vdc? I am afraid to put 20vdc onto the 51J4 relay coil. Should I be afraid? Or if my theory of loading is correct, might the output go down to 12v when connected to the relay? Just a little afraid to try.

Thoughts?
Thanks
Eugene