HAMNET Report 22nd November 2020

We are still seeing reports about Hurricane IOTA. On Tuesday of this week, the ARRL issued a communique requesting all unnecessary traffic to be kept away from 14.325 and 7.268MHz, being the frequencies used by the Hurricane Watch Net and WX4NHC, the National Hurricane Centre. Mention was made of the Honduran Emergency net on 7.180MHz and the Nicaraguan Emergency net on 7.098MHz.

On Friday, the GDACS daily news flash said that the passage of IOTA over Central America (northern Nicaragua, southern Honduras, Guatemala and El Salvador) on 17-18th November had caused very heavy rainfall over the region, triggering floods and landslides that resulted in several casualties and severe damage, only a few days after the devastating impact in the area of Hurricane ETA. Maximum sustained wind-speeds of 250 km/h had been experienced.

In Nicaragua, 36 fatalities, more than 62,914 sheltered people, and 53,130 families without a water service were reported. In Honduras, around 10,326 people were evacuated, 71,228 people were in shelters and 3 affected bridges were also reported. One fatality was reported in Panama.

In Colombia, media reported 7 fatalities (of which 2 were in Providencia Island, close to the coast of Nicaragua, where nearly all infrastructures had been damaged or destroyed). Other parts of the country were also severely affected by heavy rain and floods associated with a “La nina” phenomenon.

Over the following 24 hours, very heavy rainfall was forecast over Central America from south-eastern Mexico south to northern Venezuela, in particular over north-western Nicaragua, Honduras, El Salvador, Guatemala, and Belize.

Meanwhile, the ARRL Letter for 19th November reported that the Hurricane Watch Net was forced to suspend operations at 03h00 UTC on November the 16th, because of what HWN Manager Bobby Graves, KB5HAV, described as “deafening interference from a foreign AM broadcast station that came out of nowhere at 02h00 UTC.” At the time, the net had shifted to its 40-meter frequency of 7.268 MHz, collecting real-time weather and damage reports via amateur radio.

“This was heart-breaking for our team, as the eyewall of Iota was just barely offshore,” Graves said. “The storm had weakened slightly to a Category 4 hurricane with sustained winds of 240 km/h.” After activating at 13h00 UTC, the net was able to collect and forward reports from various parts of Nicaragua and Honduras via WX4NHC throughout the day for relay to forecasters at the National Hurricane Center in Miami. Iota was the most powerful storm on record to make landfall this late in the hurricane season.

Graves said the very strong AM signal was on 7.265 MHz. “From my location, it was S-9,” he told ARRL. “You could not hear anything but the BC station.” Graves noted that other foreign broadcast stations were heard from 7.265 to 7.300 MHz and with splattering close by.

The offending signal appeared to be from a 500 kW broadcaster in Turkey. Graves said the HWN has a long history on 7.268 MHz, but that the net is now considering a 40-meter frequency below 7.200 MHz.

Stations handling emergency traffic during the response to Category 5 Hurricane Iota had requested clear frequencies on November 16th to avoid interfering with the HWN and with WX4NHC, as well as with a Honduran emergency net operation on 7.180 MHz and a Nicaraguan emergency net operating on 7.098 MHz. It’s not known if those nets were also affected by interference from the numerous broadcasters on 40 meters.

In passing, remember IARU region 1 does not have access to the 40m band above 7.200MHz, and so the Turkish AM broadcast station had every right to be there. Sadly ionospheric conditions were so good that their AM signal was being heard in the Caribbean, just when it was not needed!

The meeting of HAMNET Directors and Deputy Directors seems to have gone well on Wednesday evening past, and a document has been prepared by Brian Jacobs ZS6YZ, laying out the exact emergency frequencies for all modes and all bands. The document needs a small amount of tweaking still, but will be distributed far and wide, once the final version is complete. Once you receive it, as a HAMNET member please have it always to hand, to be accurate when you call for emergency aid.

Sad news from the world of radio astronomy was received on Friday when it was announced that the fixed 350 metre Radio Astronomy dish at Arecibo in Puerto Rico is to be decommissioned, after it was damaged earlier this year. One of the supporting cables keeping the feed horns floating above the dish snapped, causing equipment to crash into the dish breaking a large portion of the reflector. The repair of the dish and the restringing of the cable have been deemed to be too dangerous to attempt, and so the dish will fall silent. This is very unfortunate for the entire team of radio astronomers who work there, as well as the amateur radio club established there, which has been lucky to make use of listening time on the dish. Remember though that China has in the meanwhile built a 500 metre fixed dish in the ground, called FAST, so all is not lost. We hope that radio astronomy will remain the shared science it always has been, and that FAST will provide time and listening to all who need it.

Those of you who look at the stars will have noticed the close association these nights, high in the sky, of a crescent moon, with Jupiter to the East of it, and Saturn only a little further East of that. Well, on 21st December, if you remember to look, you will see Jupiter and Saturn separated by a distance only 1/5 of the diameter of the moon, making them look like a double planet. They will be more closely associated than they have been since the Middle Ages, and Patrick Hartigan, a Rice University Astronomer says you’d have had to go back to the 4th March 1226, to see a closer alignment between these objects visible in the night sky.

The pair will be visible over to your West, and soon after sunset, and I’m not sure where the moon will be relative to all this, but I suspect it won’t interfere with viewing.

So a good pair of binoculars, or a small telescope, will give you an excellent display, all within one field of view. Mark your calendar now.

Oh, and the next available viewing like this? March 15th, 2080. You have been warned!

This is Dave Reece ZS1DFR reporting for HAMNET in South Africa.