[Heath] Off Topic Switching Power Supply

[Ron]

I built an 18vdc 1.5 amp power supply using a transformer, bridge rectifier and a 7818 regulator. Works fine, but I need to go to 3 amps. I have been trying laptop switching power supplies that put out 3 amps that produce noise on my hf rig. If I unplug the laptop power supply, the noise goes away. The power supply is used for charging batteries through a solar charger.

Questions: what is the difference between a regular power supply and a switching power supply? Can I filter out the noise on a switching power supply?