The 'noise' from my house - an experiment

[Digital]

I wondered just how much of noise I get on the radio originated from my own house. I was particularly interested in trying to pin down some interference around 27 MHz which appears on every radio inside and outside the house. So I tried turning off the main switch in the fuse box and then back on again. Results were dramatic.

(External antenna)
Power turned off:


Power back on (note the sweeping lines as things restart):


I live in a rural area, with only one close neighbour, perhaps 100 meters away, no PLT or plasma TV interference to deal with. We don't have much on in the house other than essentials like fridge, freezer etc. although I have no idea how many small chargers etc. there are plugged in at any time!

Just shows how much noise there is generated by an average home - and there's not really anything I can do about it, either!

[owza]

Interesting stuff. When I have a 'HF night' I do go and switch off the various multi-way adapters around the house. However, as you say somethings have to stay on, freezer etc. I need a 'shack' !

[ezzie85]

Its amazing the noise one digital radio generates. I listen in the bedroom, which is the quietest in the house. Just turning it off and unplugging it clears up the clickingI had on the top of the FM band. It wasn't too bad, but it was noticeable mixed in with some of the stations.

[grafter]

One other test to try is unplug the antenna from the dongle, check again and then plug in a paperclip etc. The PC itself could be generating some of that remaining noise, mine was quite noisy to begin with. I ditched as many SM PSUs as I could, replacing them with good old linear plug packs. The noisiest appliance left to deal with is the washing machine motor controller.

[nerdsville]

As grafter said, remove the antenna and check what you get.

Looking at your waterfall I'd be concerned by the regular bars, is your dongle on the end of a USB extension cable? The last time I saw something like that it was due to a dodgy cable with a poor ground/shield connection.