by: Rob Mavis AE6GE
November 28, 2014
CARP November 22, 2014 Transmitter Hunt Recap
When RF meets terrain, you can get some interesting results. The transmitter hunt on November 22, 2014 was no exception. With five teams starting the hunt
As the winners of the last hunt were not available to hide, I volunteered for the duty. In my research planning for this hunt I had identified several potential locations for the fox to hide. After scouting a few locations I decided on one that I had found during a geocaching outing a couple years ago. Which it turns out made an awesome location for the hidden transmitter.
The transmitter was a 5-watt HT connected to a 9-element M2 beam antenna. A PicCon was used to key and modulate the radio.
The transmitter was hidden 5.6 miles as the crow flies north/northwest of the start point of Letterman Park in Clovis. Right as highway 41 passes the north end of Woodward Park there is semi-hidden overpass of a road that dead ends into a field in the San Joaquin River bottom. The location is not only below the grade of Fresno and Clovis, but also butted up against the bluff on the north end of Woodward Park, all but guaranteeing that there would be no direct path for the signal to the start point.
The overpass opening faced east/west making a great funnel for the signal to propagate east up the San Joaquin River valley. Thinking that the Woodward Park bluff might be a problem for the signal to reach the start point which was south east of the hiding location, I decided to employ some RF geometry. Aiming the 9-element beam north/northeast at about 45 degrees sent the signal right towards Pine Ridge. Needless to say this created a number of signal reflections.
Astounding even himself, John K6MI along with Eric NI6G was the first team to find the fox in exactly 2 hours and having driven 67 miles. Considering that the direct driving route from Letterman Park to the hiding spot is 11 miles, that is not too bad.
After nearly another hour of not seeing any hunters I inquired where some might be. John WJ6Y and Rick W6KKO were at the Park and Ride at the bottom of the four lanes contemplating whether or not to go up 168. Considering we were 3 hours into the hunt and the other teams were strewn between Prather and Meadow Lakes I decided to give the hunters some mercy. The first clue: “The transmitter is west of the start point.” With that I heard some subtle comments on the air.
Matt KG6YLJ had to leave early not anticipating the time this hunt was taking. Heck, even I didn’t think it would have taken as long as it did.
A second clue was given, “if the dam were to break, we would be in a lot of trouble.”
At nearly four hours into the hunt the next team rolled in, John WJ6Y and Rick W6KKO. It didn’t take them too long to sniff out the micro transmitter.
After they found the second transmitter we were standing around discussing my choice of hiding places when up walks Mike KD6LDA. He had parked at Friant and Ft. Washington thinking I was inside the park and walked the Lewis Eaton Trail across the park to our location. That’s one way to save some miles.
Finally Ron N6MTS and Ken WA6OIB rolled in.
At the conclusion of the hunt a few hunters went to pizza to tell
lies, stories about their day.
This was a mileage hunt, this time the shortest time was also the shortest distance. Here are the final scores:
|1st||John K6MI||Eric NI6G||33 miles||2:00 hours||15 minutes|
|2nd||Mike KD6LDA||86 miles||4:00 hours||9 minutes|
|3rd||John WJ6Y||Rick W6KKO||99 miles||3:52 hours||8 minutes|
|4th||Ron N6MTS||Ken WA6OIB||102 miles||4:05 hours||5 minutes|