Shortwave Listening – Noise
We don’t live in a quiet world, cars, equipment, alarms, fans, tv’s radios, etc. etc. etc. We have a very noisy Radio Frequency world as well. All sorts of electronic devices can add to the cacophony that is natural RF noise. In my shortwave listening I’ve “crusaded” against RF noise in the house where at all possible and had pretty good results. I mentioned in an earlier post about a couple of “random wire” antennas I’d setup and the one wrapped around the house picked up quite a bit of noise.
It turns out that one device in particular (it had a battery charger in it – just a small emergency light), was basically noisy and using the house wiring as it’s own antenna. Additionally, I’ve found our cable box is quite noisy. Other sources of noise can be computers, computer monitors, flourescent lights (even the compact flourescents), any sort of motor-driven device.
In our house though, the Computer power supply, cable box, a battery charger (emergency light) and flourescent light were the biggest culprits. In fact, THE biggest was my desktop PC power supply. A local AM station was very hard to hear (had to turn the radio to null out the noise). After putting up with it for a while (and switching to another PS hoping it would be quieter.) I went for a more expensive upgrade to an ANTEC Power Supply 430W ATX12V 2.01 ( TPII-430 )
That much said, if noise is a problem in your home. There are a couple solutions. One way is to try to eliminate all the noise you can. The other, is to get your antenna as far as possible away from the source of noise. The two antenna’s I use (both random wire (50′), one is wrapped just under the eave of the house, the other goes from a tree to the house. The one wrapped just under the eave gets more noise (buzz mostly) than the other wire. Some frequencies get better signal though, so that’s why I keep that one around.
Noise is a constant problem for shortwave listeners and in some cases, there is only so much you can do. If you’re lucky enough to have a directional antenna of some sort it’s also possible to “null out” the noise source. (Position the antenna so that the noise is at it’s least).