[Elecraft] Strange Interference

[Fred Jensen]

Sounds like an SMPS, it may be yours :-)  I have a similar noise on 80 
only.  It sounds like a slight increase in the background noise as I 
tune across it, but it is much more pronounced on the P3, and it drifts 
slowly up and down by 20-30 KHz over time.  It rises to a 2-3 KHz wide 
peak, drops to near zero, rises to a lesser peak about 15 KHz higher, 
drops again, and continues like that until the amplitude is near zero. 
The WF shows a series of vertical, noisy, lines.

I think it's mine because when I get into a CW ragchew on 80 and have a 
higher key-down average, the drift becomes more pronounced, like 
something is heating up.  I haven't been motivated to find it because, 
while it's very pronounced on the P3, at CW bandwidths like 250 Hz, I 
really don't hear it.

Weigh your wall warts.  If they're not heavy, they're very likely SMPS. 
The one I charge my shaver with puts out a "yuuge" amount of noise.

73,

Fred K6DGW
- Northern California Contest Club
- CU in the Cal QSO Party 1-2 Oct 2016
- www.cqp.org

On 7/23/2016 8:42 AM, Terry Brown wrote:
> I am operating portable in the southern Puget Sound area currently. I
> am picking up a strange S9 interference that is very narrow but
> generally slowly moving down the bands and sometimes up the bands. It
> occurs at any one point in time at 14.030, 14.060, 14.090 for
> instance, and occurs on all ham bands with the same spacing between
> the instances of interference. I started noticing this same pattern
> of interference at my home QRH in Oregon last week. I am running a
> KX3, KXPA100, and sometimes the PX3. It occurs with preamp on or off
> and with PA Mode on or off.   I am wondering if it is atmospheric
> natural or man made  interference or if something is wrong with my
> receiver in the KX3.