[Hallicrafters] 40m noise

[Thomas C. Dailey - Dailey Services, LLC]

I often hear, very close to 7.0475 (W1AW code practice) and harmonics, what 
sounds like a large motor starting up - after a time, it slows then stops. 
I have attempted to locate it, but have heard it in other locations 
throughout Denver.  For the life of me, it sounds like a large power saw (if 
you were standing near it).

Oh well - more RF pollution.

TC