[Elecraft] Hum on KPA1500

[Andy Durbin]

"The AM radio in the car works fine in the driveway, but as soon as one starts to enter the garage, reception is covered up by a loud growl of static. Radios in a room adjacent to the garage and over the cable in the basement below also have a problem while AM radios at the other end of the house are fine."

In what way, if at all, is this observation/question related to the report of KPA1500 hum?

With reference to the original report - what is origin of the hum?  That is -  what physical object is originating the sound waves that are characterized as hum.  There was no mention of an AM radio in that original post.

Andy, k3wyc