For the past month I have been plagued by S9 plus noise on the HF bands.  The noise viewed on the spectrum analyzer was pulsed noise spaced every 2.5khz starting around 5 Mhz and ending around 25 Mhz.  While the noise appeared as spikes on the spectrum analyzer, it sounds like a frying pan sizzle in the receiver.  The noise was S9 for 30 to 40 seconds and then disappeared for about 30 seconds and then cycle would repeat.  It started at about 6 pm each night and lasted all night. 

Yesterday I was looking out my back window and I noticed one of the street lights come on for a short period of time and then abruptly shut off.  I timed it and then compared it to the noise I was hearing on HF.  They matched!  The light is about 150 feet from my vertical antenna and 200 feet from my attic dipole, both of which exhibited the same received noise levels.

This morning I got the number of the light off the light post, went to the SECO web site and submitted a Street Light issue.  At about 1 PM a SECO truck pulled up to the light, the guy changed out the lamp.and left - total time to repair was about 10 minutes.  Tonight, the street light is on and NO NOISE!  

The point of all this is to make everyone aware of yet another source of HF noise, one that can be easily identified and can be easily remedied.

Tim

AA6DQ