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 Previous: The Amateur Amateur: The Return of Unpreparedness |  Next: ARRL In Action: What Have We Been Up To Lately? |
By David Sumner, K1ZZ
May 1, 2007
With every FCC amateur licensee now permitted to operate on at least four HF bands and thousands of new General and Amateur Extra Class licensees joining the multitude on all of the MF/HF bands, this is a good time to review how we live up to the principle set out in Section 97.101(b) of the FCC Rules: 'Each station licensee and each control operator must cooperate in selecting transmitting channels and in making the most effective use of the amateur service frequencies. No frequency will be assigned for the exclusive use of any station.'
First let's do some math. Worldwide there are more than 2 million radio amateurs who are licensed to operate on HF. In the United States and Canada alone the number is about 700,000. If we leave out Novices and Technicians on the basis that their HF privileges are very limited, the number is still about 350,000 -- and growing. The numbers are similar in Europe and along the Asian side of the Pacific Rim.
If a contact between two or more stations occupies just 2 kHz -- a bit less than the width of a typical SSB filter -- a 100-kHz chunk of spectrum can only support 50 QSOs. With the depressed state of solar activity that we have to live with for the next couple of years, the total bandwidth of the bands that are open at any given time is at best a few hundred kilohertz -- enough for a couple of hundred simultaneous QSOs, and not nearly enough to accommodate all the stations that are licensed to operate there.
Obviously, this is a simplistic illustration. CW, PSK31, RTTY and some other digital modes require quite a bit less than 2 kHz. The vagaries of propagation and the use of directional antennas often permit different pairs of stations to use the same frequency without interfering with one another. But any way you look at it, if a significant percentage of us decide to get on the air on a particular band at the same time, there isn't room for everyone to enjoy interference-free operation.
A common misconception is that the FCC rules require amateurs to avoid transmitting if doing so would cause any interference to ongoing communication. Minimizing interference by, for example, asking if a frequency is in use before calling CQ, is a courtesy we owe to one another and is certainly part of the "good amateur practice" required by Section 97.101(a). However, among the dozens of references to interference avoidance and mitigation contained in Part 97, the only specific references to avoiding interference to other amateurs that apply generally to amateur stations are the prohibitions against willful and malicious interference in 97.101(d) and against splatter and keyclick interference in 97.307(b). Otherwise, as far as the FCC is concerned we're all equal, whether we have been meeting on the same frequency at the same time for the past 50 years or we were just licensed five minutes ago. Were that not the case, if we wanted to operate on a particular weekend we would have to rush home from work early on Friday to claim a frequency before they were all gone -- if the retirees would let us, that is. (You guys on the West Coast would be out of luck.)
Let's be clear about willful and malicious interference, which is prohibited. Transmitting for the sole purpose of interfering with another station is an unpardonable sin. It is never acceptable, either to the FCC or to the amateur community. If you think otherwise, please get rid of your ham gear as soon as possible and find some other avocation. If you know it isn't right but you sometimes let your emotions get the better of you and do it anyway, seek counseling -- you probably need it to curb road rage and a few of life's other problems.
But let's also be clear about this: interference that occurs as a side effect of amateurs pursuing legitimate activities in crowded bands is simply a fact of life. Interference that is truly willful or malicious is rather rare. Sometimes interference results from operator error -- we all make mistakes. Sometimes it results from carelessness -- regrettable and avoidable, but not done out of malice. Sometimes it occurs because of differences in station performance -- if you run low power to a poor antenna or your receiver's selectivity isn't very good, it's no one's fault if you're "stepped on" from time to time. And sometimes interference just happens, as when propagation changes and a station that was in your skip zone is suddenly 20 over 9. It is unfair to your fellow amateurs to assume that every instance of interference you may encounter is a hostile act.
Yes, we all should do what we can to stay out of one another's way. The FCC says we must cooperate in making the most effective use of our limited frequency bands. We are expected to operate clean transmitters (no splatter or key clicks). We are expected to use the minimum transmitter power necessary to carry out the desired communications. But we are also expected to know that we cannot claim the exclusive right to use a frequency. Most of the unpleasantness that erupts from time to time on the most popular HF bands can be avoided if we're willing to be flexible in our frequency selection.
Our MF/HF bands are a limited, shared resource. For most of the 168 hours that make up a week, there is plenty of room for everyone who wants to operate. At peak times -- weekends and evenings, especially when the maximum usable frequency (MUF) is low -- it can be difficult to get a word in edgewise. If we accept this and adjust our expectations and operating patterns accordingly, and if we improve our stations and our operating skills, the amateur bands will continue to be -- as they have been for decades -- the most effectively used portions of the HF spectrum.
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