Don’t you love…
… events like the current CQ WW SSB contest? No? Wait, not so fast.
QRM is great!
It’s the ideal moment to put receivers, filters and antennas to the test. A mediocre receiver will crumble like a cookie made by a 1-year old. A filter with pathetic characteristics will be exposed faster than the Lewinsky scandal. Crappy front ends will relieve themselves, forcing you to wipe their behinds with toilet paper before the stuff hits the PA fan. No testing equipment known to man can beat the interference created by some hams.
One station, 20 KHz of space occupied
How do they do it? I have no idea. A crackling noise, still perfectly readable 10 KHz down and 10 KHz up. All my filters proved as effective as a paper coffee filter (No. 4 size, cone shaped). DSP’s don’t process. Noise blankers don’t blank. Roofing filters are leaking like a sieve. Where’s my roofing contractor when you need him? Decreasing the sensitivity didn’t help much either. I’m stunned. These stations, by the way, were all located in certain parts of Europe.
Could it be that they’re just strong? Nah. UK, US and Canadian stations were sometimes just as strong, or even stronger, but their signals were gone within 3 KHz up or down. These (polite, patient, receiver-friendly) hams were the ones who got points from me. They deserved it.
Yesterday evening I visited a meeting in my home town, Almere, organized by D-star enthusiasts. Personally I don’t care much about D-star (yet), but that doesn’t mean I’m not interested. After all, it’s an extension of our hobby. It proved to be an interesting evening, with lots of room to get questions answered, and enough time for some hands-on experience.
When you want to demonstrate something, convinced that everything will work perfectly, Mr. Murphy will often pay you a visit. Although there was an internet connection in the cafe, no connection could be made. It’s one of the disadvantages of digital communication – if your service provider is down, or won’t allow you to change parameters in a firewall, your system is dead in the water. The same applies to technologies such as Echolink.
Hams are creative people by nature, so the problem was solved quickly by converting an iPhone into an access point.
All current hardware was present: USB dongles, mobile transceivers, handhelds, a bunch of computers and even a working repeater. I made a few QSO’s with stations in New Zealand and a mobile station in Canada. It worked fine, with no packet loss at all, but I have to get used to the audio quality. Compression ratio is high, and it shows.
It’s a reminder that the word ‘digital’ doesn’t mean a thing when it comes to image or audio quality. It just depends on the codecs used, and the available bandwidth you have at your disposal. The background noise (some hams were real chatterboxes!) didn’t make reception easier either, haha!
When it comes to adopting D-star, pricing proved to be the biggest hurdle. D-star equipment is quite expensive, too expensive for some. This the reason for D-star picking up slowly in the Netherlands.
Some more pictures (click for larger version)
During the renovation of my house, I had to remove all antennas. I wasn’t too happy with that, but in the end I was glad I did. After more than a decade, corrosion proved to be a major problem. My trusted 5/8 wave vertical (Sirio GPE), was about to fall apart and kill someone in the process. I decided to spend a little bit more money and bought a CB antenna made out of glass fiber and graphite.
President Black Pirate 5R
When it comes to giving names to even the most ordinary antenna, manufacturers of CB antennas can’t be beaten. Black Pirate? Come on. First of all, it isn’t black at all, but white. There’s a reason for that: the material used for black glass fiber appears to have shielding properties, which is the last thing you want. The only thing making sense in the model name is ’5R’, which stands for ‘Five Radials’. Yes, you can buy the antenna without, but I would advise against it.
Radials only take up space, and make no difference at all. Right? Wrong. Believe me, I tried. For years and years, with different brands and models. As soon as I skipped the radials, my base noise level went up. Way up! The bandwidth of the antenna decreased. The radiation pattern changed. RF feedback into the shack sticked its ugly head around the corner. Forget it guys. Spend the little extra money on the radials. You won’t regret it.
This antenna had to become suitable for 10 meters, not CB, so a small modification was in order. I calculated that I had to cut 30cm (11.8 inches) off the top element to make the antenna resonate at 28.500 MHz. That was spot on – no tuner needed, SWR meter didn’t move a millimeter. Extra adjustments can be made by moving the ‘SWR ring’ at the base of the antenna. Performance for DX is great, thanks to an extremely low angle of attack and about 5dB gain (dBd).
Worth every penny. Works around the globe with 25 Watts or less. I dislike the silly name though, and never mention it during QSO’s (unless asked for).
Antenna type : 5/8 + 1/4 λ
SWR. value : 1,1/1 adjustable
Gain (dBi) : +9,9 dBi
Max. power (W) : 2500 W PEP
Bandwidth (kHz) : 4500 KHz
Weight (Kg) : 2,600
Lenght (mm) : 5270
Base type : fixed mount 50 mm
Material : fiber/graphite
Connector : SO 239
No. of radials : 5
Radial lenght : 1120 mm
Frequency : 25-29,5 MHz
Impedance : 50Ω
One of the few websites I visit daily, is Spaceweather.com. There’s a good reason for that: there’s a direct relationship between the number of sunspots and the 10cm flux. The higher the flux, the better the conditions on HF generally are, especially on the higher bands. As long as the number of sunspots rises, and the sun doesn’t burp up large Coronal Mass Ejections directed to our planet, we’re a happy bunch of hams. A CME directed to Earth causes a geomagnetic storm, which in turn can cause an HF blackout. If a storm is sever enough, more problems can arise though.
The Carrington Event
Solar cycle 10 was the tenth solar cycle since 1755, when recording of solar sunspot activity began. This cycle lasted 11.3 years, beginning in December 1855 and ending in March 1867. The maximum smoothed sunspot number (monthly number of sunspots averaged over a twelve month period) observed during the solar cycle was 97.3, and the minimum was 5.2. There were a total of approximately 406 days with no sunspots during this cycle.
On September 1–2, 1859, the largest recorded geomagnetic storm on Earth occurred, known as the Carrington Event. Aurorae were seen around the world, most notably over the Caribbean; also noteworthy were those over the Rocky Mountains that were so bright that their glow awoke gold miners, who began preparing breakfast because they thought it was morning. Telegraph systems all over Europe and North America failed. Telegraph pylons threw sparks and telegraph paper spontaneously caught fire. Some telegraph systems appeared to continue to send and receive messages despite having been disconnected from their power supplies. (source: Wikipedia)
According to some the current solar cycle, number 24, resembles cycle 10. A long stretch of spotless says, followed by a not-so-high average number of sunspots, but a totally unexpected high number of flares and CME’s. I wonder what would happen if the sun would spit out a similar super flare today. Would our satellites fail? Would all modern ways of communication fail, such as cell phones and the internet? Would we be out of power for a long time? After all, this happened before, and not too long ago. The answer is, of course, that we don’t know.
The role of hams
Assuming a worst case scenario, would our equipment still work? Would hams become the backbone of the world? We like to think of us that way, as we’re able to communicate under the most difficult circumstances. A car battery will do just fine, or a generator. Some ham shacks are solar powered (mine will be in the near future). Again, we just don’t know. Although I would hate to see everything fail, I must admit that my curiosity wins the battle on many occasions. Shouting “Bring it on!” might not be appropriate, but then again…