I operated from the same location in 1999 that I used in 1998 using bumblebee number 74. A smaller sized Jackson Harbor memory keyers was used rather than a CMOS-III keyer and improvements to increase the power of the Sierra using a 2N5109 driving an NTE-342 final were completed. The Sierra's output power was 5 watts on 40, 20 and 15m and about 4 watts on 10m. The weight of the battery was reduced from that of two 7 Ah gel cells to only one 4 Ah gel cell with a light weight, flexible solar panel used to maintain the charge. Antennas were a 40m dipole that also worked on 15m and a 20m dipole. The 40m dipole could be loaded on 10m with the use of an EMTECH ZM-1 antenna tuner. Time did not permit construction of a light weight wattmeter, so the OHR WM-1 made the trip again.

Two forms of interference were noticed during the operation. The first appeared to be caused by the charger between the solar panel and the 4 Ah gel cell. Frequently during the operation the gel cell would reach full charge and the charger would float. When floating the charger pulses at a low rate creating RFI. I have two thoughts on how to address this problem prior to returning in August, 2000.

The second interference may be an image response problem as it appeared to be an off frequency FM modulation which was not continuous in nature, e.g. one side of a two-way communication. When operating 21.060 MHz the image response of the Sierra would be 30.890 MHz. I hope to have an opportunity to return to this site to try 15m using the Sierra with a 15m Dunsbar bandpass filter in the antenna line to determine if the filter will eliminate this second interference.