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HS0ZHM
Greg Lee
General Class
HS0ZHM Ham Since 2006
Thailand

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Information

Other Callsigns
KI6GIG (General)
HS0ZHM (Intermediate)

My Ham Radio Interests
Emergency preparedness / communications, Weather observation

Free Emergency Preparedness lessons series: Several parts (i.e. Lessons 1-6, 9-10) of the 12 part series have been released. Although created originally focusing on natural disasters relative to Nan Province, Thailand, some of the information is general and can be readily adapted to other areas. For example, water is critical in all disaster situations. The information on prepare and replenishing water supplies can be useful in most disaster situations. We hope to complete the remainder of the series in 2012. The completed lessons are available at www.neighborhoodlink.com/RTC-TH_Tech/pages

Free MEWS (Mobile Emergency Weather Station) and weather observations lessons are available at my website. MEWS enables amateur radio operators to make valuable weather observations in disaster areas where there are few or no working weather stations. These weather reports can help relief helicopters to know flight weather conditions in the disaster area. Relief coordinators can use the weather data to understand the situation in the disaster area to better coordinate logistics and supplies for survivors.

You can read about MEWS at the following links:
1) QRZ.com at http://forums.qrz.com/showthread.php?293778-Mobile-Emergency-Weather-Station-Complete-quot-How-to-build-and-use-quot

2) Hamuniverse.com at
http://www.hamuniverse.com/hs0zhmsparky.html
http://www.hamuniverse.com/hs0zhmmewslessons.html

To access the lessons, visit www.neighorhoodlink.com/org/rtcth, then go to the “Pages & Links” section, and click on “RTC-TH MEWS Lessons".

The lessons are in English. I welcome any help from other amateurs to translate these lessons to other languages.

Thanks for visiting my page. Best wishes to you.

Equipment
Radios:
Yeasu FH-912 (Thai version of VX-170)
ICOM 2200T

VHF 2m antennas:
Spectral Isopole 144
Thai made Slim Jim (aluminum)
Arrow J-Pole
Home brew 450 ohm ladderline Slim Jim (re: Hamuniverse.com)
Home brew Slingshot beam (re: Hamuniverse.com)
Home brew Hentenna (copper) (donated by N7YLA)

EchoLink User node 384040 (active)
EchoLink Link node 520300 (in progress)

Other Interests
Environmental education, self-sufficiency and sustainability of small rural family farms, soil and water conservation, rain water harvesting, photography, applied geography

Clubs
ARRL (US org), RAST (Thai org), GERC (Glendora Emergency Response Communications, Glendora, CA; US org); POARC (Port Orford Amateur Radio Club, Port Orford, OR; US org)

Thunderstorm and Strong Gusts

From HS0ZHM

4/5/2012 8:35:48 PM (0 comments) Add a commentAdd Comment


31 Mar 2012 in the dry season in northern Thailand. A thunderstorm hit with heavy rain (19 mm in about half and hour) and strong winds gusting to an estimated 45-55 km/hr (Beaufort scale visual estimate). When I heard the winds gusting, I grabbed the camcorder and headed for the upstairs back porch to check on the unguyed 9 m AGL mast in the backyard.

The winds were gusting so strong that I had trouble standing and holding the camcorder steady. I crouched down with my back against the wall, framed the mast in the viewfinder, and started recording. I video taped for about 2 1/2 minutes and before the wind started blowing rain into the porch and spray got over the camera lens obscuring the view. I took the hint and headed inside.

The storm subsided. The mast stood up well without any guy wires, so it past the test. Viewing the video tape was a surprise. I don't recall the mast flexing that much in the breeze and gusts. More surprising was the government weather station less than 200 m north of us reported "calm" winds for the entire afternoon. "Calm" winds are less than 1.5 km/hr. OK, my eyeball estimate using the Beaufort scale is a subjective judgment call. But take a look at the 5 pics I posted.

The first shows the mast under calm conditions. The other 4 were taken from the video clip. I added a red dashed line for the normally "plumb" mast alignment under no wind/calm conditions. The upper part of the mast is 2.5 cm diameter steel pipe. The top of the mast is 9 m AGL. The cross arms are about 1 m to either side of the mast. Max deflection is about 0.8-0.9 m. My eyeball estimate could be off, but do you really think a "calm" wind (less than 1.5 km/h) would make the mast deflect 0.8-0.9 m from the vertical?

Go figure. If the wind speed at the weather station less than 200 m away was calm, all I can say is that it is clear the winds and gusts were NOT very calm in my backyard.

PS. Yes, in the future, when "calm" winds are being reported during future thunderstorms, I think I will plan to just keep the mast lowered at all times unless I need to hoist up an antenna. Why tempt fate even though it stood up to the gusts this time without any guy wires.


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