SARA at Dayton Hamvention 2019

Autor: Tom Hagen

SARA was represented at the Dayton 2019 Hamvention this year again with a double booth in the Volta Building at the Greene County Fairgrounds in Xenia, Ohio.  Ed Harfmann, Jim Sky, Bogdan Vacaliuc, Dave Fields, and Tom Hagen manned the exhibit for the 3-day event on Friday, May 17 through Sunday, May 19.  Several hundred people stopped by and I am continually amazed by our visitors’ breadth of knowledge and experience.  A number of possible SARA collaborations could result from these contacts.

Our exhibit included posters explaining HI emission, thermal emission (blackbody radiation), electromagnetic spectrum, and cosmic background radiation.  Ed showed off his TBD tracking generator and a couple of interdigital 1.42 GHz homebrew filters he built.   Ed also put together a kiosk slide show that will be useful for future exhibits at SARA conferences and other public events.  We displayed two Itty-Bitty Telescopes (TV dish antennas) and explained to folks how they radiate in the 12 GHz range using just a surplus dish and an inexpensive satellite finder meter.  We set one dish up outside our building and we were able to detect radiation from people and showed them how we can detect the sun and broadcast satellites.  Tom brought his VLF monitor with a small center-tapped loop antenna that received the US Navy VLF stations in North Dakota and Washington State.  The big 24 kHz station NAA in Maine was unfortunately off the air during most of the event. 

We took in 7 renewals from SARA members who stopped by and 8 new people signed up for SARA membership.  We sold two SuperSID kits, including one to a gentleman from Colorado who’s planning set it up with a group of high schoolers.

The weather cooperated pretty well as there was some rain during setup and teardown, but not during the conference itself.  It was hot this year.  I noticed it hit 90°F on Saturday!

Some other notes:

A number of people who stopped by remember the “bird droppings” problem that Wilson and Penzias dealt with in their cosmic microwave background work.  Another gentleman we talked to had direct experience with the experiment and told us that they even investigated the welds inside the horn antenna as possible noise sources.  He told me that they ground the welds down flush and covered them with copper tape. 

The noise was not eliminated for reasons we now know!

One visitor showed me a frequency plot of an HI observation he’d made.  He’d never done this before and he was asking me if I thought he was getting good results.  After looking at it for a bit, I noticed that he had not 1 emission line, but 3, distributed across the frequency axis.  On his first attempt, he had detected 3 HI clouds.  I told him I was quite impressed!

Ed was interviewed about SARA by a representative of the weekly podcast called “100 Watts and a Wire”.


The people at the HamSCI exhibit talked to us and informed us that the SuperSID program was mentioned in one of their presentations.  Collaboration with the HamSCI project might be a good thing for SARA.  

See http://hamsci.org/ for more information.

So we finished up on Sunday, a little tired, but satisfied that another Hamvention is in the books.