7690 kHz, constant hum, 30 Aug 2009 @ 0715 UTC

[weatherall]

On 7690 kHz, I came across a strong signal with a constant humming sound.  If I tune up or down 5 kHz, it's not audible anymore, leading me to believe that this some kind of broadcast.  The tone reminds me of the sound of a small prop plane flying overhead, but at a constant pitch.  There's volume fluctuation, but I can't tell whether or not it's due to fading.

EiBi doesn't list anything for this frequency, and it isn't in a broadcast or ham band.  Unfortunately, I'm getting a lot of noise, so I can't make a decent recording.  Any ideas what this could be?

(Eton E5 + indoor wire antenna, northern California)

[cmradio]

Is the hum 50/100Hz or 60/120Hz?

Those mystery carriers are a source of head scratching

I've been hearing one of those on 8361 KHz for months with no modulation.

Peace!

[weatherall]

Is the hum 50/100Hz or 60/120Hz?

Those mystery carriers are a source of head scratching

I've been hearing one of those on 8361 KHz for months with no modulation.

Peace!

I just used a tone generator, and 100 or 120 Hz sounds similar to what I heard.  I was using AM on my radio as well.  Thanks for the info; I'll post more logs here if I find it again.