Curious interference on 40m...

[wb4iuy]

I'm wondering if any of you hear what I'm hearing, and/or what it might be. I'm hearing a noise that is sort of a fast "wah-wah-wah-wah-wah-wah" sound, and drifts from around 7.285-7.295. Sort of a warbling, wandering noise. Signal strength is up and down like QSB, so it makes me think it's not local. I've been hearing this on 40m for quite some time, and it's driving me crazy when I try to work AM on 40 at the top end of the band. I hear it on all of my rigs at in Studio A & B.

Have any of you heard this, and does anyone have an idea what it might be? I've done the property check, killing power, sweeping with a portable receiver, etc. I'm lost :-/

Dave WB4IUY
www.WB4IUY.net

[WD8KDG]

Dave,

You're off to a good start, but more information would be helpful. Are you able to hear the "same signal/rfi on other frequencies?? If there are other harmonics, it could be someone's new Christmas toy/rfi generator in your neighborhood.

The portable SW receiver has been my best tool for locating rfi. Tune it into one of the harmonics and walk around the neighborhood. Shorten the telescoping antenna as the signal gets louder. Been able to walk to the front door where the #$#$@@ was located. Good luck with neighbors, they might be glad you hear their new toy!

Be friendly, polite and all that stuff if the source is from another house. A bottle of Scotch worked here in Springtucky on one neighbor.

Craig,

[Opcom]

Can you record it and load the file? It would be interesting to hear for comparison.

[wb4iuy]

Thanks for the feedback, I'll hunt around the neighborhood a bit more. Also, I'll record the signal tomorrow (always seems to be worse during the day) and upload it. I watched it today, and by the end of the afternoon, it had wandered up to about 7.310.

[Blaine N1GTU]

I get exactly what you're describing on 40 mtrs, turns out it is my Linksys wireless router.
If I put my hand on the router the frequency warble slides out of band, I unplug the power and it goes away.
Sometimes it turns out to be the switching supplies, I changed mine and it still does it.
I will have to replace the device.