University of Oregon / Oregon State University Joint Transmitter Hunt – Search and Rescue Drill, 4/16/2022
The plan was to start at the UO student union at 11 am. At 11 am, it was hailing, so we waited for it to stop – basically 11:30…when it became nothing but blue sky.
By 11:30, everyone who was going to be there was there: K7NAR, W7HER, N7JI, KG7HTE + 1, and N7DPW (he placed the hidden transmitter, also called a bunny or for us, a RF Duck)., Hannah W7HER is the UO ham club president, Declan KG7HTE is the OSU ham club president.
The “RF duck” was an “Anytone 878 UVII Plus radio” set up to beacon APRS on 146.56 every 30 seconds. This was challenging because there was only about 1 second of signal available for direction finding every time the radio sent an APRS signal, so if you took your eyes off the S-meter…you had to wait for the next one. It was also possible to swing the antenna around during a packet, but you had to be ready for it.
Nate, Hannah, and I made up a team. Declan and his girlfriend made the other team. We each had a few radios, a yagi, and attenuation available.
We immediately noticed that DFing in an ”urban” environment is really hard because signals echo and bounce off of every building in sight, and sometimes you can’t get to a high spot.
This was, more or less, our path.
We just couldn’t get a good heading for a while between Lawrence and the theater. Eventually, however, we wandered the right way and the “radio without an antenna” started to squawk. From there, it was just walk, wait, measure, repeat.
Note the little rubber ducky on the ground. The other team found it a few minutes after we did. And then it started raining. And hailing. And graupel-ing. That stuff hurts when it hits your bare skin. Anyway, this was a serious challenge. We learned a few things, too:
Urban settings create lots of reflections.
Urban settings may have lots of RF sources.
An old Yaesu VX-150 (2m only) can work better than a Baofeng or a new, expensive radio with a wideband receiver, in such settings.
Scott N7JI
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