Man made noise identification

[brandon]

For the past week I have been picking up a strange noise mostly in the 6 MHz band about every 30 kHz or so. The noise can be heard at all hours of the day and is starting to drive me nuts. Thankfully, it can be nulled out, but I still want to tackle the source and am curious if anyone knows what could be causing it? I suspect it comes from some type of power supply based on audio samples from the ARRL RFI from home appliances site. Nothing changed on my end so it must be from a neighbors house

Here is what it sounds like
(first part in AM, second part in USB mode)

[kb5udf]

Let me know if you figure it out as I have something at my QTH very similar. It goes from AM broadcast band, upwards. It does seem limited or absent at 28mhz, but irritating at 14mhz.

JB

Follow-up to my post. I think I found mine, it was a sharper image, ionic breeze. I'll just blame my wife for that one.

[CLynch7]

My DTV converter makes a similar noise.

[k9rzz]

Is it on discrete frequencies (like 5601.0 and 5603.0 but not in between) or broadband (makes no diff. if you tune the dial). I'm guessing a spark from something. Sounds almost 60hz.

[WouffHong]

Also check the following sources - ones I have dealt with.

1) Household Light Dimmers (such as those used to dim overhead or wall-powered lights)

2) Photocell-activated outside lights.

3) Flourescent desk-top or lamp/ceiling energy-saving lights.

4) Neon-type light or bug-zapper around the neighborhood

5) loose connection on a power circuit or bad Wall-Wart.

If you can find an old handhelod radio or AM-capable rig (Like aTH-F6A or VR-500 rcvr), wander around and see if you can pinpoint a "hotspot" around your property.

Lastly, on a nice day, hit the main breaker for your home, ascertain if it has gone, and if so, repower up and start shutting off breakers, on at a time..

Just some thoughts from an ol' EMC guy.. ;-)
(Most probably covered in the ARRL doc?)

Wouff.

Originally Posted by brandon

For the past week I have been picking up a strange noise mostly in the 6 MHz band about every 30 kHz or so. The noise can be heard at all hours of the day and is starting to drive me nuts. Thankfully, it can be nulled out, but I still want to tackle the source and am curious if anyone knows what could be causing it? I suspect it comes from some type of power supply based on audio samples from the ARRL RFI from home appliances site. Nothing changed on my end so it must be from a neighbors house

Here is what it sounds like
(first part in AM, second part in USB mode)

[brandon]

Thanks for the tips. I will do some sleuthing this weekend.
As for frequencies I notice it on 6515, 6535, 6545... usually between ~10-30kHz increments.
@kb5udf: I hear ya mate... those Ionic Breeze purifiers are real noise makers. That's also what this noise reminded me of, but its not as consistent (in time) between burps Thankfully its an easy fix to unplug those things but god forbid if some neighbors obtain one!

[nickcarr]

Originally Posted by brandon

For the past week I have been picking up a strange noise mostly in the 6 MHz band about every 30 kHz or so. The noise can be heard at all hours of the day and is starting to drive me nuts. Thankfully, it can be nulled out, but I still want to tackle the source and am curious if anyone knows what could be causing it? I suspect it comes from some type of power supply based on audio samples from the ARRL RFI from home appliances site. Nothing changed on my end so it must be from a neighbors house

Here is what it sounds like
(first part in AM, second part in USB mode)

Wow that's really bad. It definitely sounds "power-like" to me. Possibly a bad transformer in your neighborhood..?

[k9rzz]

Well, if it's descrete frequencies then I'm leaning towards something digital.

Got your computers turned on when you hear this? Heck, with my little Eton portable, I can listen to myself type right over WWV !

[nickcarr]

Brandon, I forgot what radio you are using but have you tried from running from DC power? It would be interesting to know if it comes thru without using AC power.

If it is clear on DC power, then it's something coming thru your AC system and you can buy an ICE transformer to clean it.

[fritz73]

I would try the suggestion from nickcarr, and also here is a thought: I was getting the same issue when I was using a small switching power supply (a Radio Shack model) , and after I stopped using that and went to an Astron conventional type (RS-35M) it totally disappeared. I learned to stay away from switching power supplies if possible after that.