*update 1/1/2012* Comments are closed for this article.
It’s always fun to take a look at search engine terms. How did visitors end up here? In 99.9% of the cases, search engine terms are predictable: a certain Yaesu model, a specific antenna or something similar.
A few days ago, I found this one: “Jamming a Ham Radio transmitter”.
This puzzled me. What was this person looking for? Why was he searching for ways to jam a Ham? Immediately, fantasy kicks in. For a start, he (let’s assume it’s a male) must be desperate. Maybe he has a crappy TV, the worst coax lines in the world, no decent grounding, or still uses HiFi equipment dating back to the eighties. As a result, he hears and sees things that shouldn’t be there.
When generic HiFi or TV equipment starts acting as receivers for, lets say, shortwave signals, something is wrong, really wrong. Assuming that a Ham has everything working as it should, interference should be absent or minimal. Consumer electronics just aren’t supposed to pick up our signals.
Unfortunately, consumers can’t be expected to understand this. They will rather think “This amplifier was the most expensive one could buy at the time. Expensive = good”. For us, it’s a time to talk to, and educate the consumer. It’s also a time to do everything we possibly can to solve the problem.
In most cases, replacing old coax lines by properly shielded ones, making sure the equipment is grounded and installing ferrite clamps, rods or ‘pig noses’, will do the trick. Wire around ferrite acts as a choke for RF currents and time base noise.
Not only will our neighbors be free of interference, we will be too. While we’re at it anyway, why not kill the interference generated by badly designed switching power supplies, as found in modern LCD and plasma TV’s, plaguing us on our HF bands?