The Sound of Silence, Part II

After the recent surge in 10 meter contacts due to Sporadic E propagation I reported in my last post it seems that hams have again lost interest, yet meanwhile the 11 meter CB DX scene is still going strong. This echoes observations I've made in the past about the differences between what hams and CBers consider "good" propagation.

Here's what I observed... Around 1630 UTC (0930 PDT) on 22-May-2009 I was mobile near San Jose International Airport. Figuring that 10m Sporadic E might bless us again with another day of great propagation I was tuned to 28.400 MHz, but heard nothing on or near that frequency. I figured at first that the Es just weren't there, but then remembered that the CBers and Freebanders often congregate around 27.385-LSB as their "DX calling channel". I tuned down to 11 meters and man, what a ruckus! I was hearing stations from all over the western US, some on the pre-defined CB channels and some were VFO-tuned to whatever frequency they happened to be on.

So as I've asked before; why the dramatic difference in activity? Clearly there was Es propagation to support contacts in the 10 meter band. Yet 28.400 MHz sat there idle, while 27.385 was so crowded CBers were changing frequencies to continue their conversations. One explanation suggested to me was that since CBers have only 11 meters they're forced to make the best of what they have, while hams can easily say "10 meters isn't yet as solid as I'd like, I think I'll drop down to 20/17/15 meters and see who's around down there." Fair enough, I guess. It still seems to me a shame that we're not making better use of the spectrum we have available to us.

Summer Es - Sporadic E season

In the past week we've seen some increased solar activity; solar flux peaked at 74 and that led to some interesting band openings. I worked LY1000A in Lithuania late last night (20-May-2009) on 20 meters -- an opening to Europe near midnight local time certainly qualifies as "interesting".

The summer sporadic E season (often referred to as "Es") kicked in today with reported 10 meter openings from the west coast to the east coast. I worked KJ7OX in western Washington state just before midnight local time; solid copy on him and after I signed off he was still going strong.

Given that 10 meters was pumping I also listened up on the 11 meters CB band. As expected they were going strong too; I was hearing a lot of AM stations down below channel 23 and I also learned that apparently CB channel 38-LSB (aka 27.385 MHz) is the popular sideband DX calling channel. It was good to see the hams having as much fun as the CBers for a change.

There was an interesting study done on Es propagation by Art KA5DWI; compiled over four years of PropNet monitoring data it shows that "sporadic E" may not be so sporadic after all. One noteworthy finding; Es propagation during ARRL Field Day weekend is typically poorer than the preceding and following weeks.

The Sound of Silence

Last November we drove down to Disneyland in my wife's van, and I wired up a VHF/UHF rig and mag mount for the trip. Ever since the phone systems failed due to overloading during the relatively minor October 2007 Alum Rock quake I've been nervous about relying on cellphones in emergencies. I spent some time researching repeaters along the route, and more time programming everything into the radio.

All for naught, apparently. During the trip I was struck by the almost complete lack of traffic on every repeater I tuned in. It wasn't a problem with my equipment; there just wasn't anyone on the air. Even in the densely populated Los Angeles area, the entire twelve hour trip was mostly a never-ending chain of silence. The most traffic I heard was on linked systems such as the Cactus Intertie and the WinSystem, but that's to be expected because they have dozens of connected repeaters and all it takes is one person talking somewhere on the system to light them all up.

On my base and mobile rigs I have a lot of local repeaters programmed, ready to go. And yet at any given time; nobody's talking. Pick up the mic, announce "W6DTW monitoring".... and listen to silence. Reminds me of the This Week In Amateur Radio "Random Access Thought" segment by Bill N2FNH about a repeater that died when a spider crawled across a circuit board; shorted himself across a resistor; killed the repeater...and nobody noticed. And yet; try asking your local frequency coordination council for a frequency pair and you'll get told "there's nothing available". The howling wind of silent FM static is blowing through most of our local repeaters just as it was through the repeaters I tuned into on the trip to Southern California. So how is it that all of the frequencies are spoken for..?

Things are not much better down in the HF bands, or perhaps I should say not much better in the legal HF bands. Given that we're currently coming out of a low point in the 11-year sunspot cycle you might be tempted to allow that the amount of traffic will be low. Especially in the higher frequency bands like 10 meters, where popular wisdom says there's little propagation during the day and certainly none at night. So the 40 and 20 meters bands have some traffic (mostly contesting), 17 meters opens up around noon for a while, and we're starting to hear folks on 15 meters. But for the most part; few stations are on the air and silence above 21.5 MHz is the rule.

So then why is it that on any given weekend day, if you listen above 27.405 MHz into what's been termed the Freeband, you'll very likely hear a lot of traffic? I hear strong stations coming in from around the Western US and Mexico. Is there something odd about propagation that creates a difference between 27.915 MHz (aka the freeband "Redneck Skip Calling Frequency") and 28.400 MHz (aka the amateur "10 Meter Calling Frequency") so that one is active and the other not? Surely the Freebanders don't have some kind of secret technical prowess that allows them to punch through where amateurs cannot? The reality is likely that amateurs simply don't believe that there's good propagation without sunspots, so they don't tune in and "no propagation" becomes a self-fulfilling prophecy.

I find it amazing that while the great swaths of spectrum which amateurs can legally use sit idle; another group of people who are sometimes called "pirates" (agree or disagree with the term as you wish) are happily making use of frequencies which are right next to a band that amateurs will effectively ignore for a good 25%-40% of every sunspot cycle. Yes, Freebanders are operating illegally according to FCC regulations. No, I'm not a Freebander. However; I do have a sense of respect for them. They are (from what I can see) more enthusiastic and aggressive about pursuing the hands-on technical aspects of radio than many hams. They're out there modifying radio equipment on their own---which they have to do because there's no legal way to buy freeband radios. They're not sitting around waiting for sunspots to come back so they can get good propagation; they get on the air and take what the sun gives them on that day.

That's real radio.