The AM Forum

...hi from tim...i'm attaching an mp3 of this noise/qwarm i'm receiving..this thing showed up, abt 2 months ago...it is only on 160, and it can really be strong...i live in the sticks, nothing around me, but man, this is annoying.....give a listen, and give me your thoughts...

..tnx...tim...

..sk..

Hi Tim,

Just to axe the obvious questions first...

Does it go away when the antenna is disconnected?  You are sure it's not an internal buzzy in the RX?  I once had an FT-102 that did exactly that - it needed some bypassing in the synthesizer.


Does it drift up and down the band or were you tuning the RX?

Give us more details, like time of day habits, any stronger directions, (loopstick test)  does it get stronger with propagation or stay the same strength? etc.

General question to all: Is that a 60hz tone with harmonics or maybe a 120 cycle tone with harmonics?

T

I have heard almost the exact noise *here* in my own house.  It turned out to be a florescent light fixture (in my house, in this case, but it could just as easily come from a neighbor).

Other things I have heard do this are fish tank heaters and even electric stoves with temperature controls (like mine).

Battery chargers also can produce a similar sound, and I have heard them do so.

But, I'd start with lighting - the sound is pretty much identical to the one I had here.

Regards,

Steve

Sounds like a power line arcing over an insulator to me.
Something like the sound the bad street light out front of my house used to make, but that was much slower, on for 3 minutes, off for 3 minutes.

This noise sounds like the V wires on the neon sign transformer I used to play with as a kid, Frankenstein type stuff!

BZZZAT....BZZZAT....etc...

Brett
N2DTS

Sure sounds like power line arc-age, but certainly could be a flourecent light or other appliance.

73,  Jack, W9GT

...if you notice, it kinda fades-in, then fades-out....i only hear it with the antenna on, a 160 metre dipole....i've checked around here with a portable rcvr, and cant find anything local...by 11pm local time, it is not as strong, and i know that after 1am, it is completely gone...it is worse at my "prime time", around 8-10pm...i hear it from abt. 1700-2200kc...

..tim..sk..

Got any electric fences in your area?   They go on and off and sometimes short out.

..no, nothing like that...i can tell ya, it is not here at all, till abt. 8pm...there is nothing industrial, or whichever...it has a regular "pattern"...like clock work, is repeats itself...almost like a scanning/sweeping radar, or something...

..sk..

Many RFI recordings on this web page. You may be able to match your noise with something here:

http://www.arrl.org/tis/info/HTML/rfi-noise/ (http://www.arrl.org/tis/info/HTML/rfi-noise/)



Sam / KS2AM

Tim,  make absolutely sure it's not eminating from your house!   Shut off the power to everything but your shack, and check.  Then you can  seriously check out your neighbors.   Good luck.   I use a good portable comms receiver (a Kaito 1103) to snoop around with.  Found my  cable TV noise that way.

Tim, do you have any street lights in your area? It sounds like one that is failing to come on and the start-up sequence is continuously cycling. It could be a fair distance (.5km - 1km) from your house, which might explain why your portable is not hearing it. It's odd though, that it is gone by 1:00 am, but then again, perhaps the light finally starts up at that point. The lone streetlight at a road junction in my area produced a similar repetitive-cycling buzz about 20 years ago when some part of it failed. Whatever it is, hope you track it down successfully.

Rob AEX

To me, it sounds like the noise I heard once when someone was cooking something in the microwave, and I had my old AM radio on.
Shelby KB3OUK

We had low pressure sodium streetlights in VT that would crap out regularly. They'd go off, then buzz as they came back on, then be quiet for a while until the cycle started over. No idea what a mercury bulb would sound like, or how often it could cycle. But it does have more of the 'power line arc' or something breaking down sound to it. Good advice to check stuff in your own buildings first, and go from there. You might be surprised what you find (and never would've suspected).

The street lamp noise usually cycles every two to three minutes as the lamp re-starts then extinguishes. Your noise is almost steady with a couple of breaks.
There was an incident next door to me in Maryland that turned out to be an under-the-counter flourescent lamp (one of those no-balast types). Nothing was wrong with the fixture, worked perfectly, but there were times that when turned on it would blank out 160M. It was a hit and miss thing. The neighbor said she turns it on every night.

But your're saying that it's not your QTH.
 
And underground utilities don't start arcing at a certain time every night.
Any fish tank heaters?? Is your water heater electric??
The interference sounds very strong that it blanks out the band completely. When it stops the AGC in your RX opens up and band noise returns.
Do you have an Oscope connected to your receiver as a mod monitor??? what does the 'Scope trace look like when this interference hits the air??
An RFI guy for PEPCO in Wash DC could tell what type of electrical interferenc it was either by the sound or a 'Scope trace. He was good.
Fred

I've had this fun before here.

I think it's a salty insulator on a nearby pole. As Fred said, it takes your rx a few seconds to come back to life, so it's surely right in the neighborhood somewhere. Put the car radio on am and tune to the top of the b-cast band and go for a slow ride getting close to the poles. That buuzzzzzzUMP, then silence, then buzzzUMP over and over sounds like an arc starting and then stretching out enough with heat to kill itself, then starting over again.

Maybe it stops after a while because the load lightens as people go to bed. ::)

Water heaters and heating equip would do it longer than 3 seconds at a time. A florescent light ballast getting ready to puke might sound like this.

As said, first thing to do is kill the entire house, including any out building and so forth right at the main breaker to rule out anything on your site causing this.


After that, it's a witch hunt thru the neighborhood, but it's so damn strong, it should be easy to find once you have something running on batts that has good ears.

Good luck man. It took me almost 2 years to finally convince CL&P around here that they suck and I'm right before they changed out 3 pigs on the same pole that were each shot to hell and making a lot of racket. 

Sounds like Dave's Elevator ;D