Saturday, January 03, 2009

New Google Earth Coordinates for Pt. Reyes, CA

Google Earth appears to have greatly improved its images of the Bolinas area. This is on Point Reyes, north of San Francisco, and is home to some truly historic old antenna farms. Visibility of antenna hardware used to be practically nonexistent, but now you can make out quite a bit.

We begin our tour at 37°54'52.32"N by 122°43'30.26"W. These coordinates put you right alongside the venerable RCA transmitting facility used by proud old KPH for commercial maritime communications. Much of this building was shared by RCA's real money making operation. This was KET, the West Coast hub for many point-to-point fixed-station links that connected up the entire Pacific Rim in the days before satellites. In the past few years, the facility has also been used by KSM, a new Maritime Radio Historical Society station with a commercial license on traditional coast station frequencies.

This building was added onto, and both halves are clearly visible. At least on my monitor, if you look real hard you can make out the many open-feed wires coming out of this building to the two long wooden structures to the northwest and southeast that show as white lines. From there you can easily trace the H structures that still carry largely intact balanced feeders to the two major parts of one of the world's great antenna farms.

At either end, right angle marks on the ground suggest the presence of large rhombics, once used by the point-to-point station. Closer in, a small service road leads southwest to a square building right on the cliffside by the ocean. This is the original "Power House," that held the Marconi company spark transmitters and subsequent RF alternators.

The massive antenna structure for these is mostly gone, but several of the concrete bases for the 300 foot support towers remain. One of these is just northeast of the building, looking like a white donut. Shadows make it possible to spot many poles that hold up wire antennas of various types. Several of these are still in use by the Maritime Radio Historical Society.

The land is now part of the Point Reyes National Seashore, and some of the main transmitting building is now used for offices of "Commonwealth." They at least used to operate a small 12-MHz sea surface research radar near the old Marconi building. It does not interfere with maritime frequencies.

Now go almost due north a bit, to coordinates 37°55'32.46"N by 122°43'52.57"W. These put you dead on top of the transmitter building used by NMC, the US Coast Guard Communications Area Master Station Pacific (CAMSPAC Point Reyes).

It's hard to miss the fairly new log periodic just due south, and various other circles, masts, and square fences make it easy to see the positions of various HF antennas. This farm is actually right next to KPH, separated by a low fence which shows up as a line running southwest to northeast all the way back up to the street (Mesa Road).

More on Point Reyes later.