Depending on where you live, and how dense the housing is, the noise
could easily be coming from your neighbor's gear.

The usual culprits for 50 to 100Khz noise are switching power supplies.
They live in TVs, Fax machines, telephone answering machines, battery
chargers, computers, monitors, printers, LED and vacuum fluorescent
clocks, and the biggest supplier of this noise of all, so far, the
compact fluorescent lamp.

If you want to check your house for sources of this noise, the easiest
way is to kill all the breakers except for one, and unplug everything
in that circuit except for your receiver. If you still have the noise,
it is being conducted into your house from elsewhere.

-Chuck, WA3UQV

No Spam (ckh) wrote:


I have an S9+ noise level on all the HF bands. I've suspected my
computers, fluorescent lamps, BPL, but I'm not certain. It
sounds/looks like this.


XxxxXxxxXxxxXxxxxXxxxXxxxXxxxxXxxxxX
0----v----1----v----2----v----3----v----4

The scale is, oh, 40 meters from 7.0 to 7.4, each lowercase x is
S7-8 pink noise. Each uppercase X is a roughly 10 kHz wide cluster
of shot-noise, S9+.

The uppercase X's are about 55 kHz apart. It's all approximate and
seems to be different at different times.

I've turned off all the computers and other appliances, alarm
clocks, etc. There is no change in the noise.

I hear it on all my receivers which include 3 SB-303's and a
Signal/One.

any ideas?

de ah6gi/4