I am not an expert — far from it — but I have learned a few things about noise levels from my own experiences

“Noise level” — or whatever term you use — usually refers to man-made interference
The first thing to understand is that most of the noise you receive comes from your own setup

I’m lucky to live in a rural area where the noise level was low from the start
But I haven’t always been so fortunate
I’ve lived in noisier places so I know the difference — and dealing with it can be a real battle

Many friends who share the hobby with me have asked for help with noise problems
My first question is always: Do you have a good grounding system in your shack
If the answer is no we work from there — start with grounding
From there I ask other questions which you’ll see in the rest of this page

Ground

The house grounding and the shack grounding are connected
There are chokes on various paths: on the shack cable entrance, on safety ground of sockets, and in other places
Cables are thick: 16 mm² for main grounding; smaller equipment may use 6 mm²
The negative terminal of power supplies is also grounded
Tower rotor radials — everything is connected to the station ground
Use the shortest cable possible
If a cable is longer than ~30 meters install a choke at both ends
Use large grounding conductors whenever possible

Grounding equipment

Chokes and ground on antennas

Where possible bury coaxial and other cables underground
Antenna feed points have chokes
The coax from shack to antenna switch has a choke
The antenna switch is grounded when not in use
All antennas connect through chokes into the station’s ground

Control cables

All control cables are choked — one choke before entering the shack one in the barn (since the cable run is long)

Mains filters

I use a mains filter at the entrance of the shack.
All other equipment is tested to ensure it doesn’t introduce noise into the receiver.

Some final words