By David Waters, AC4JF
In this hobby, each of us will deal with a certain problem sooner or later: Malicious Interference. The perpetrator is often referred to as a “Jammer” or “QRMer” or much worse. They have the potential to totally disrupt our communications. The irony here is that, to a large degree, we empower them to do this. If you don’t quite understand how this is possible, please read on.
Let’s start by looking into a Jammer’s mindset. Why do they cause QRM? I imagine that the reasons vary greatly. Most likely it is a convenient way to vent frustrations that build up due to severe personal inadequacies. Maybe it is a control issue. Maybe it is a vindictive thing aimed at a certain person or group of people. It could be some other pent up frustration or anger not really directed toward anyone or anything in particular. These are probably the top reasons for all QRM, although, in my opinion, to understand the exact motivation is not critical to effectively deal with the problem.
What does the Jammer want? What do they need? What do they expect? I believe that these are the key questions that we need to consider. The Jammer wants to know that they are being heard. They need to know that they are being disruptive and effective. They expect us to get angry and to show it. Let’s look at these facts one at a time.
When a carrier appears on a frequency with bad noise or no audio, our first instinct, being the helpful sorts that we are, is to let them know they have a problem. It could be a legitimate station, or it could be a Jammer testing out his setup. Keep this concept in mind and make a determination before you comment. Sometimes this is a tricky call to make, and a wrong decision could cause problems either way. On the one hand, if the station is legitimate with a problem, they need to know it. On the other hand, if the station is malicious, they don’t need to be told that they are causing problems. If it is a legitimate station with problems, they won’t be trying to cover anyone up. They shouldn’t “double” with someone over and over. The carrier will appear at the “right” times, however, it will have bad or no audio. If it is a Jammer, the carrier will appear at the “wrong” times. It will be obvious that their timing is calculated to be disruptive. The first well meaning, unknowing ham that says something like, “You have a good signal, but no audio,” provides valuable information for the Jammer. The Jammer now knows that he has at least one person’s attention and that he can be heard.
So, what to do? During a net, the answer is easy. Always let the net control station make the call. It’s part of their job. During a round table discussion, the determination could be harder to make. In a one to one conversation, it may be a little easier. No matter what the situation, listen and think before you speak! If you accidentally acknowledge a QRMer at this stage of the game, all is not lost. Your plan, however, has been compromised and your defenses have been weakened.
Time will soon tell what you are truly dealing with. Once the determination has been made that you are dealing with malicious interference, it is critical not to acknowledge any more of their transmissions. What now? Act. Nothing less than your best Academy Award winning performance is called for here! Even if the QRM is so bad you didn’t hear the other station, act like you did! Make something up if you have to. One should develop a knack for this and be prepared to use it. This will be very frustrating to a Jammer, and often causes the interference to cease quickly. If the Jammer feels like they are not being very disruptive or effective, despite their best efforts, the excitement for them quickly fades. Remember, any comments about them, no matter how small or innocent, will reinforce the bad behavior. Ignoring the Jammer will maintain our control, and have positive psychological effects for us. Keeping control makes it easier to keep cool. Keeping cool at all times, no matter what happens, is critical.
With the last two points in mind, this third point should never come into play. The Jammer expects us to react to them in some big way. The Jammer hopes to get a large response out of a large number of people. Threats, promises, curses, remarks about their parents, etceteras are never justified. They only add fuel to the fire. If this Pandora’s Box is opened, it is hard to close it. If you feel you must respond, TURN OFF YOUR RADIO!
This has proven to be a very efficient and effective method of dealing with a Jammer. The more skills we develop to ignore the perpetrator, the quicker this technique works. And it does work! Every amateur on the frequency has to understand and play the game if this is to be effective. Spread the word about this approach. Operate with the mindset that any unidentifiable signal is possibly QRM. Think before you respond!
Of course, these suggestions are only a first line of defense. A good offensive plan should also be in place in case the QRM continues in spite of our best efforts. Direction finding, transmitter finger printing, documentation, and old-fashioned detective work will help to remove the cloak of anonymity and build a case against the Jammer. A predetermined meeting place should be established so that any discussion on the subject will be held on another frequency or band, or ideally, on the telephone. Never discuss the QRM on the afflicted frequency. Such offensive planning is very important, but it is outside the scope of this article. Remember that the point here is to stop QRM in its early stages and altogether prevent the need to go on the offensive.