eHam.net News

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Bellefonte Area Middle School Students Work On Out-Of-This-World Project:

Posted: 15 Feb 2018 04:18 PM PST
http://www.eham.net/articles/40855


For a federal agency dealing in rockets and space travel, NASA operates by
kind of a loose timetable. All that Bellefonte Area Middle School Principal
Summer Garman and her students have been given is a 120-hour window at the
end of February wherein 7 to 9 minutes will be allotted to a conversation
with personnel aboard the International Space Station. Student engagement
was important to Amateur Radio on the International Space Station, the
group playing operator to two very long-distance parties.


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Ham Fest:

Posted: 15 Feb 2018 04:18 PM PST
http://www.eham.net/articles/40854


This past Saturday I attended the Collinsville Ham Fest: no it was not a
pork jubilee. What a Ham Fest is: partly a show, a swap meet, and
socializing for Amateur Radio enthusiasts. I know there are a lot of
preconceived ideas about hams (short for amateurs), some think they are
geeks; that ham radio is a dying group - why would anyone need a two way
radio with computers and cell phones? As far as being geeks, radio was
probably the first geekdom, going back to the 1920's. Radio was really the
first mass media and the world fell in love with the technology. For a few
decades, the purchase of a radio was quite prohibited. The average wage
back in the day was 5 bucks a week, and a commercially built receiver could
cost hundreds of dollars, so folks improvised and built their "rigs." Later
others experimented with building two way set ups. If you could get the
active device, which in that time was a tube, you could shortly be
listening to news broadcast or music, soon after talk radio was conceived.
This was the norm till after WW2, when the surplus market was flooded with
military gear and parts. As far as it being an old mans hobby, even today
that is rather misleading. While I was in the convention center, I closely
watched the people milling through the sales area. While there were a
substantial number of old men, there were also quite a few women, and an
astonishing amount of young people. There are many facets to the hobby.
I've found that the younger members of the hobby enjoy using their laptops
and even pi setups for digital communications. All of which is quite
inexpensive, portable, and can be powered from an array of alternative
power sources. Examples would be PSK 31, JT 9 and JT65. Some people collect
old test gear, others like restore decades old equipment; myself I like to
take those odd and end pieces and build working pieces to use on the air.


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Wi-Fi-connected 3D-Printed Objects Communicate Without Electronics:

Posted: 15 Feb 2018 04:17 PM PST
http://www.eham.net/articles/40853


With technologies of all sorts having invaded our lives in every domain it
is interesting to see how new technologies are being developed that exploit
existing technologies as if they were part of nature instead of man-made.
Wi-Fi is a good example. Because Wi-Fi access points are everywhere
navigation systems can use databases of Wi-Fi access points to accurately
calculate their position. Wi-Fi access points thus have reached the status
of landmarks. Another emerging technology based on Wi-Fi signals is Wi-Fi
backscatter communication where passive objects use the Wi-Fi signals
surrounding them to send information to a receiver in a way similar to a
mirror reflecting sunlight. Since Wi-Fi signals are reflected by objects
they can superimpose information on the signal by modulating their
reflectivity. A receiver can detect the object and extract the information
by comparing the Wi-Fi signals it receives over different paths. Without
modulation all the packets should contain the same information whereas
modulated reflections are different and therefore detectable.