Mt. Miguel beacons , San Diego

Mt. San Miguel, DM12MQ, is located 13 miles inland from the harbor of San Diego, and 10 miles north of the US border. The summit is 2560 feet and provides an unobstructed view of the San Diego and the Pacific Ocean toward the Hawaiian Islands. Due to the unique geographic layout of the southwest coastline, beacons located on San Miguel have a line of sight path to the LA basin, about 120 miles north.

History of the 10368.360 beacon:
In the summer of 1989; a beacon was constructed by Kerry Banke, N6IZW, and Chuck Houghton, WB6IGP (SK), in San Diego. The design incorporated a WB Gunn diode and a NB ‘brick’ oscillator. The WB output was on 10.265GHz and operated under the Call sign of N6IZW/B while the NB was crystal controlled on 10.368100GHz and used the call WB6IGP/B. A single slotted waveguide antenna was fed by both signals while the ID was CW and generated by a microprocessor.

The QTH of the beacon bounced around for a number of years. Finally, Jerry Petrizzi, W6VLF, the beacon found a home at the KNSD-TV’s transmitter site on Mt. San Miguel at 2,560’. For the next 13 years the transmitter operated, only being shuttered during contest weekends and for maintenance. During these years the crystal for the NB ‘brick’ continued to age causing the carrier to drift to 10.368070GHz at last check.

When Jerry retired from NBC in 2007, the beacon was relocated about 200’ NE to the transmitter site of KPBS-TV where it operated until 2009. Finally, after 21 years of continuous operation, the beacon was removed from service. In its state of reincarnation, by Greg Bailey, K6QPV, the power supply, GPS reference, PLL, ID’er, and RF driver are mounted in a 19” cabinet which is located in the KPBS building.

A coax transmission line carries the RF drive to the PA; which is (shown above) located in an outdoor housing atop the building. The 27dBm output of the amplifier is connected to a piece of slotted guide which is directed toward the LA basin.

History of the 1296.300 beacon:
This beacon was originally constructed by Jack Henry, N6XQ, with an output of approximately 10W, and was located atop Point Loma at Jack’s residence. In 2007 (approx.) it was given to Rod Atkins, WI6M, when Jack moved. Prior to Rod returning the beacon to the air, he became ill (SK) and thus the beacon was passed to K6QPV who installed it on Miguel. This beacon has not been modified and remains in the layout that N6XQ constructed. It is crystal controlled and operates at 1296.300 MHz (+/-100Hz). The CW ID, which repeats every 2 minutes, contains the Lon/Lat, grid square, and K6QPV/B call sign.

History of the 3456,3 beacon:
Dan Bubke, K6NKC, constructed the Miguel 3456.3MHz beacon. It is GPS locked and has an output of approximately 15W. The horn antenna, directed toward LA, was constructed by Jerry Petrizzi, W6VLF. It has a calculated gain of 14dBi. The CW ID repeats every 2 minutes. This beacon is presently operating under the call sign of K6QPV/B.

History of the 5760.300 beacon:
Greg Bailey, K6QPV, constructed this beacon in 2010 using miscellaneous parts from a Qualcomm OmniTrac unit originally manufactured to operate in Brazil. It is GPS locked and has an output of approximately 1W. The antenna, constructed by Dave Glawson, WA6CGA, was donated by Lee, KD0IF, and is a slotted waveguide with a gain of 18dBi. The CW ID repeats every 2 minutes. This beacon is presently operating under the call sign of K6QPV/B.

(Additional beacon information can be found in Feb/March, 2011 SBMS Newsletter)