2015 Puerto Rico bicycle tour, Day 11

Feed assembly at Arecibo ovservatory

Wednesday Decenber 16, Hatillo to Manatí

45 km / 28 miles

Map for day 11

Closeup of the catwalk at Arecibo Janet and I left the hotel right after breakfast and got to the observatory about 9:40. Mr. Ángel Vásquez, Director of Telescope Operations, came to meet us at the parking lot by the guard shack and personally drove us to the observatory. Mr. Vásquez was born in the town of Arecibo and has been at the Arecibo radio observatory for 38 years. He showed us a wall full of photos of famous visitors.

The reflecting dish is 1000 feet in diameter, built into a natural depression in the mountains. You can barely see the dish from the center, but the feed assembly is prominent. It is suspended over the center of the dish from three cables going to towers at the perimeter of the dish. You can see the top of one of the towers at the lower left of this photo. Compare this photo of the catwalk with the two human figures to the photo at the top of the page to get some feeling for the scale of this installation.

The 430 MHz klystron We got to see the giant klystron transmitting tube that was used for the recent amateur radio moonbounce operation on 432 MHz. Some radio amateurs enjoy the challenge of bouncing radio signals off the moon and listening to the echoes. That normally takes a transmitter with maximum legal power, a huge antenna and a very sensitive receiver. But with Arecibo on the other end of the circuit, even a very modest station can communicate via moonbounce.

The UHF control console We also got to see the 1950ís-era console for the 432 MHz transmitter. They used waveguide for feedline for the moonbounce operation. That's Sr. Vásquez on the left.

Label plate for control console

Efrain at desk with monitors Here's a corner of the control room with operator Efraín. In addition to the information on all the monitors he can see the dish through the large window behind him.

Monitor showing inside the dome One of the monitors out of the picture behind him shows some technicians doing maintenance inside the "dome", the bulbous thing that hangs from the feed assembly over the dish. Inside the dome are antennas as well as equipment. He told me the dome has three stories, which again gives some sense of the size.

Racks of equipment with Sr. Vasquez in front The equipment racks shown at right hold nine HP8648 signal generators, which I helped design when I was at HP.

SETI equipment Arecibo is involved with SETI, the Search for Extra-Terrestrial Intelligence. This rack records hundreds of channels of information while the dish is being used for other things. The data are then sent via the Internet to thousands of volunteers whose computers process the data when not otherwise in use.

Pathway next to wall bordering the ocean After the tour, Janet drove me back to the hotel in Hatillo where I retrieved my bike (the morning receptionist was much more personable than the evening one) and did the ride a couple hours after everyone else. The first and last parts of the route were on busy PR2, but the part in the middle was quite nice. After leaving PR2, there was a pretty stretch on a wide stone-paved path next to the ocean. At the end of the path, where you turn left on PR681, there was a convenience store and an ice cream shop. I bought an Arizona juice, ate my PB&J sandwiches and finished with two scoops of coconut ice cream.

Arecibo lighthouse on promentory across the bay Fence & gate looking toward entrance to small bay

Dinner tonight was at a Longhorn restaurant next to the Hiatt hotel where we are staying. I donít think anyone actually had steak, though.

Back - Top - Forward