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Field Day 2011

It was Sweetwater Summit again this year but rather lonely as far as amateur radio activity goes. The NFS area is about 30 miles north of Bridgeport, CA. The grid square is DM08jm (AMSAT calculator for 38.5122N, 119.208W). It is very quiet except for what Jerry calls the slow Missouri elk (cows) or, in RF terms, when the Boily genset was fired up. It is also far enough away from civilization for good star gazing without light pollution. Cell phone service was also nearly dead with even Verizon iffy with augmentation.

The antenna mount this trip was a 22′ fiberglass pennant pole mounted on the rear of the B-van.

First up was a G5RV hoisted on the pole with one end tied to a sagebrush and the other to a rock. That made for good listening but the SWR ran between about 2 and 5. One problem was that the antenna really needs a bit more than 10 meters elevation and my pole only provided only 6 or 7. The ends of the antenna were only about a meter off the ground. This might have worked but I didn’t have the antenna tuner set up to keep the transmitter happy.

The second effort was to experiment with an Icom 706 coupled to an AH3 antenna tuner connected to a wire run up the pole. This was like a mobile setup with a 6 meter whip. It was an unaccustomed level of convenience for me: Hit the ‘tune’ button on the radio, hear the relays in the tuner clacking for a second or so, and then see the indicator on the button show that the antenna is set to frequency. The tune process often resulted in a few db of signal strength when listening.

The problem with the 706 was that nobody could hear me. One issue was the power supply. The battery lead was rather long and voltage dropped to below 12.0v under load. When a genset was powering the B-Van converter, I couldn’t really tell what the voltage was because the output of the old Magnatek was not clean at all. The IC 706 didn’t seem to mind the noisy power feed much but I’d hate to think what it’d do to transmit signals.

Another issue may have been the chassis ground connection. I stuck the lead under a rusty bolt that was convenient but was not up to par considering the importance of the connection.

An old Wilson WE800 was used with a mag-mount for monitoring 146.52. This thing went nuts when the Magnetek converter was going. It also appears to be suffering during the daily temperature swings and had some other problems. I also could not find the microphone for it. I was using an Icom SM-8 but that isn’t well suited to portable use. It was also fun trying to figure out how I had re-arranged the controls! I need to look at the six ‘memories’, I modified one to use a dip switch for the last 2 digits and the others were set via diodes. The radio was new in 1977 or so. It might still make a good low power 2m radio for monitoring or maybe even APRS.

This highlights a few things to do before the next Field Day effort. Mobile and portable antennas are always an interesting challenge and getting a stable clean power supply is another.

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