Arecibo

China's 500 meter FAST, also built in a natural basin, became fully operational this year.

 

I do believe that phased arrays tend to be narrowband, as wideband microwave waveguides and other hardware are much more difficult to build and compensate.

Arecibo appears to have been set up for 0.3 to 10.0 GHz, which is quite wide.

 

uh-huh......

History repeats?

 

Platform and dome have fallen 400 feet into dish.

 

I listened to a podcast about Arecibo on government funded radio.
Link:

Short Wave - The Long Legacy Of The Arecibo Telescope

It's a shame, but unlike some instruments - this one was in a harsh environment and, it would seem, marginally maintained based on pre-storm photos.
I was thinking that they were going to put the squeeze on for some band-aid money, but I believe now that it might be a good time to scrap Arecibo and maybe look for another crater.

Perhaps one in a drier climate......

 

Considering the progressive collapses, is it reasonable to presume that the support cabling architecture doesn't support lowering the central platform to reduce stresses? Even all the way to the ground to unload the support system?

 

Pretty sure as of today that has been taken care of by gravity. It is fully collapsed now

 

Having lived for nine years on a small island, I know that island life is a constant battle against salt and rust. I'm not sure how much of an impact the sea had on the antenna, being about 10 miles from the coast, but I'm still surprised it lasted as long as it did. Now I don't feel quite so bad about our 10' satellite receiver dish falling off its mount in spite of the endless hours I spent scraping, brushing, and "rustproofing."

 

LOL

Rustproof is like waterproof.......both of which are false advertising.

I remember pulling some instruments out of the surf zone after a number of weeks and I was surprised at the amount of corrosion that occurred on our stainless steel bits and pieces.
Our mechanical engineer reminded me that they were stain-LESS.


THOSE pieces-parts weren't exposed to a tropical rain forest AND sea salt.

 

Aluminum beverage cans go through a washing and etching process to prepare them for internal and external coatings. It involves several kinds of cleaners plus hydrofluoric acid and ends with a final rinse of de-ionized and purified water. The stuff eats right through 316 stainless steel.

 

There must be a story for why Jerry knows this.

 

Yup, and it's a long one; 22 years of beverage can making before becoming a missionary. Started at entry level, moved through a few steps to mechanic. Went to school and became an electrician where I worked on everything in the building. Then supervising electricians and millwrights.

As an electrician, I got to unwire stuff that was in the way of the millwrights patching or replacing SS panels. As a supervisor, I was the guy who scheduled that stuff.

 

I was thinking in terms of before second or third stages of the collapse series.

But from the photos, it looks like the much of the cost and safety concerns of the controlled demolition project have now been solved.

 

takes a whole lot of NG or electricity to recycle many metals, iirc. But it beats mining.
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