Today, I took a screen grab of my most persistent interference problem. I don't know what it is or where it comes from, but it pops up quite regularly, sometimes several times each hour. I haven't bothered with any thorough investigations as it is intermittent and some days doesn't seem to be as frequent. Here is a screen grab I took of this interference this morning.
Interference bursts
Wouldn't you just love some of this? What on earth could it be? It's strong enough to create noise with my strongest transmitters. I am so thankful this isn't constant.
Here's another odd one I have come across recently, as highlighted nicely in SDR Data File Analyser:
More interference
This one looks like the kind of noise my internet modem/router makes, only it isn't my router. This produces irritating whining sounds on the channel and will mask the weakest signals.
Regular random noise burst
This one is really annoying as it can be very regular. It looks like a thermostat and it is strong enough to wipe out all bu my two strongest transmitters: Belmont and Tacolneston, but it even produces a static sound with these.
My summertime interference
This is what I call my Summertime Interference, because it looks like this is a summertime only phenomenon. It's a solid block of noise which affects most of the band but, as you can see, it has a very sharp starting frequency.
Last year I observed this from approximately 200 degrees (south-south-west) between April and October. Then it stopped. It has a very precise on/off pattern, coming on for about five minutes and having a white noise sound, then becoming slightly quieter for the next five minutes and sounding raspy.
It stopped over the winter months but seems to have resurfaced in a slightly different guise. It is now about one minute 'on' and one minute 'off'. It's still the same white noise when it's 'on', but it is completely silent when 'off'. As a guess, I wonder if this might be the product of nearby solar panels charging. Living on England's sunniest coast has its disadvantages if so as solar panels are very popular here.
Rapid pulses
This one is not as bad as it looks. I can't hear it, only see it. It doesn't seem to present any great problem.
As I drive around town, monitoring continental signals, I am immediately aware of just how much interference there is all around us. It's practically non-stop. Even at my location, which is relatively quiet, I have a subtle white noisy mush in the background all the time. It's only very weak, luckily, and tends to reduce in strength overnight. It's like a living, breathing organism, waiting to surface at random. Some days it's slightly stronger.
At other times I hear random bleeps, buzzes, raspy sounds on individual frequencies, broadband bursts of white noise. All these troublesome creatures are living close by, waiting to pounce.
Having DXed in remote mobile locations I have heard how quiet the bands can be and, trust me, a town or city dwelling is never truly free from noise when you have sensitive receiving equipment of the kind we DXers use. All you need is one piece of noisy equipment, a psu, a thermostat, a light bulb, etc. and you can wave goodbye to weak signal DXing.
