Interference on 30m

I was in the shack making a few adjustments to the Echolink software configuration. The K3 was on 30m APRS with the speaker volume turned down to almost inaudible. Suddenly, at about 1410 UTC, I heard a buzzing type of interference. I looked at the TrueTTY waterfall and saw there were interference bars every 50Hz right across the screen, strong enough to prevent anything from being decoded.

50Hz is the mains frequency here in the UK. With a sinking feeling my immediate thought was that one of the neighbours had discovered a new way to make the HF bands unusable. Then I remembered that Lynn, KJ4ERJ had posted a screenshot of similar interference only the day before in an APRS forum. I checked back, and sure enough the interference Lynn had seen in Florida was exactly the same.

I don’t know what it is, but I don’t think even my neighbours are capable of generating interference that could be heard across the Atlantic. It’s still going strong 30 minutes later. I haven’t seen an HF band wiped out like this since the Woodpecker fell silent back in the ’80s. Well, at least I’ve got Echolink!

Julian Moss, G4ILO, is a regular contributor to and writes from Cumbria, England. Contact him at [email protected].

One Response to “Interference on 30m”

  • Jamie MM0JMI:

    I have just seen this pattern on 40m, from 7.036MH to 7.070 MHz, with something close to 50Hz spacing between the bars (FLDIGI), wiping out the 40m digital channel. This is from the East Coast of Scotland, in a remote location. S9 + 10dB, detectable with both vertical and horizontal antennae, but stronger on vertical. Anyone know what it is? (22:15GMT 2nd April 2015)

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