AmateurRadio.com

The other night while at the radio I notice my Astron power supply for no reason was giving out a loud hum for about 4 seconds then nothing. Now I have two Astron supplies an RS-20 and RS-35 both being beside each other I was not sure which one it was. After a process of elimination I found that BOTH supplies were doing it. This was taking place while the supplies were under load from any my radios during transmit and when both radios were not transmitting. I tested each supply with all radios off and still got the intermittent hum. The other items that are on the same outlet  like my PC did not have any troubles at all. I did see....well I thought I did....the compact florescent bulbs on my ceiling fan flicker.
I thought it was them and it did seem when I turned off the lights it went away.....well that theory was short lived when the power supplies hummed again with the lights off....how romantic is that, lights off and the glow of two Astron power supplies....I digress.... I then ran an extension cord to another outlet that I knew was not on the same circuit as were the trouble was coming from. That seemed to be the fix things the  supplies are running great now with no more hum. As I write this post it seems that the over head compact florescent light (that is on the same circuit) has a flicker to it. I changed the bulbs to incandescent lights and the flicker is still there. I checked the voltage at the outlet and it is 120.1 volts AC. I have gone down to the main panel and checked all the connections and they were fine.  I am going to have to investigate loose connections and neutral troubles on this circuit this weekend.  But for now the Astron supplies are running just fine on the other outlet.