Results of the March 27, 1999 Mini All Day Transmitter Hunt

Hiders: Bob WB6JPI

It was a mild and foggy day for the March 99 mini-allday thunt. I had a plan. The concept was to hide a transmitter with a signal that looked to the hunter as if it were coming from very far away. It needed to simulate diffraction and a drop off as you got nearer. Of course, the signal would have to go away when you got on the other side of it or it would be obvious that it was coming from the nearby peak and not scattering off of it. I thought about using Baldy as the site, but there are too many other nearby peaks that wouldn't be radiating and would give the trick away. I chose Margarita Peak over San Clemente. This peak normally will be the path for all transmitters hidden in the Yuma area. The road went around the peak such that it was naturally well shielded to the East and South. Perfect.

I set up a low power transmitter at the start site a few days before the hunt (Monday) and used that as a beacon to pinpoint the hide site and insure that it would be running the minimum power to be heard at the start, but no where else. The 300 mW transmitter with a 19 inch spike antenna was clearly heard at the hide spot with 30 dB of attenuation. I thought that this would be great. The hidden T would run 0.3 mW into a 10 dB antenna and be LOUD at the start. This low power could easily be mistaken for diffraction. To further the effect, the hidden transmitter antenna is up-tilted at 10 degrees. This should help the simulation of the diffraction drop off with depression angle. Such a fine plan.

Arriving at the site at 8 Am Saturday morn, I witnessed the TQQ transmitter, the breakfast discussion and the details of MI's late start. It was all very clear at the site. The 10 el beam, horizontally polarized and pointed directly at the start was set up 12 ft off of the ground in a cove with 100 ft walls at about 30 degrees making a natural shield for the backlobe. Nothing was in front of the antenna, so there would be little multipath to reflect energy east or south. Or even North. The transmitter was a 300 mW Alinco DJ-C1 modified with a BNC connector and programmed by a PiCon controller. The Alinco operated from its charger base which was fed 12 v from a sealed 7AH 12V lead/acid battery. This transmitter went through a HP attenuator set at 30 dB. This made the output 0.3 mW into a 13 dB gain antenna or an ERP of 6 mW. Great.

Well, not so great. They couldn't hear it at the start. I raised it 10 dB. They still were not hearing it. I raised it another 10 dB and still no response. Finally at 0 dB on the Attenuator they heard it, but now the ERP was up to 6000 mW. Disaster….Musta been that darned inversion layer. They tell me the signal got much louder as you came down off of PV. Well maybe not so bad.. The signal disappeared completely 1/4 mile from the transmitter on the only road in and there was essentially no signal for the next 30 miles. Then only a very small tweet on the SSB for anywhere on the east side (the only way in). It looks like the best solution to getting to the transmitter would be to leave Palos Verde going down the coast to somewhere short of Oceanside. The signal is quite strong and direct bearings should clearly indicate the location as the gate at the end of the Margarita Peak road. Then simply drive some 55 miles with no signal to get there. I think the shortest was is to go back to the 74; go east to the dirt road (4wd) Killen Trail to Wildomar Road to Tenaja road in another mile or so the Tenaja road enters the Cleveland Nat'l Forest and becomes 8S01, a 6.5 mile dirt road to the hidden transmitter. This route may be short, but it is tedious (ask Don, KF6GQ). I think most would take the 74 to Washington or the 15 FWY and go south the Clinton-Keith road to Tenaja. This is on pavement at least until you reach the 6.5 mile 8S01. It was also fun as the 8S01 road is not shown on any of the Delorme maps, the LA and nearby AAA map. It is shown on the AAA Riverside County map and the Cleveland Forest map.

Unless Scott went to Yuma, the plan was a near total loss. (Scott was never heard from again). I don't think anyone was fooled into thinking that it was a mountain diffraction.

About 2 PM I felt people would be mad at having another hide at Margarita Peak and all of that drive with no signal, so I hid a second unofficial transmitter east of the 15 FWY on Clinton-Keith Road. This transmitter sent a CW message that said it was there just so you would have something to listen to and blasted the east side of the mountains with about 3 watts with 30 percent duty cycle. This transmitter was dubbed T0 and the signin sheet clearly indicated it was not part of the scoring.

Seven teams started at the start and 6 of these found the unofficial transmitter. Four also found the real transmitter.




CALL            T-1                     T-0
               MILES    TIME           MILES   TIME
KF6GQ          106.25   15:11          132.10  17:17  WINNER
N6YKE          160.60   16:05          190.80  17:55
N6XFC/N6MJN    272.80   23:55          112.70  14:48
KC6TNJ         314.60   23:56          118.00  14:05
N6AIN           DNF                    131.00  14:47
N6ZHZ/KD6CYJ    DNF                     GOT THERE
N6MI            DNF                      DNF