satellite

Engineer's Corner
9:42 am
Wed September 24, 2014

TheEC: 8pm Newscast Tuesday Night

The USNO Master Clock
Credit Ben Simon

If you were listening to the 8pm newscast on Tuesday night (Sept.23) then you got to experience our new service that helps make sure your watch can be set to the most precise time possible!

Okay, that's not really what happened.  The newscast started out with the USNO's "time guy" (you can hear the automated time announces by dialing (719)567-6742 in Colorado; the DC numbers don't seem to work).  

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Engineer's Corner
10:41 am
Mon March 31, 2014

TheEC: West River Runs High Through 1290

The West River runs high through the 1290AM tower site. Water levels are a good two feet above normal.
Credit Aaron Read

As many of you know, RIPR owns and maintains the 1290AM site on the Providence/North Providence town line.  Our NPR satellite downlink is there, and we lease the frequency to our friends at Latino Public Radio.

In the past, the site was largely a pond (Whipple Pond) with Douglas Ave forming part of a dam in the eastern corner.   After the torrential rains of 2010, the dam broke and the pond drained.  Now the West River flows freely through the site.

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Engineer's Corner
3:00 am
Tue October 15, 2013

TheEC: More Fiber in RIPR's Diet

Fiberoptic cable splicing tool.
Credit Aaron Read

As all RIPR fans know, we are an NPR member station.  That means we get a lot of our programming from NPR, the BBC, and other providers, via our satellite dish.   The dish is medium-sized as dishes go, but it’s pretty big in real terms: 3.7 meters (12ft) in diameter.   There’s quite literally nowhere to fit a dish that large at our studios in 1 Union Station, so instead it was installed out at our 1290AM transmitter site in North Providence (we still own 1290, but we lease it to Latino Public R

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Engineer's Corner
7:56 pm
Wed July 24, 2013

TheEC: "Normal Accidents"

Jack Lemmon in The China Syndrome

Most people have heard of the "Three Mile Island" nuclear power plant accident of 1979.  But it's famous among engineers for being a "normal accident", in that there wasn't any one thing that nearly caused a meltdown of catastrophic proportions...it was a series of little things inside a highly complex system that all happened as part of "normal" operations.   None of which, by themselves, was terribly problematic.  But they all happened at once, and that was a problem.

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Engineers Corner
9:48 am
Thu October 11, 2012

TheEC: Solar Outages

A Galaxy-model Satellite.

It has to do with our satellite downlink from NPR. We have a hefty 13-foot-diameter satellite dish, located in North Providence; there's no room for it at One Union Station! It points to "Galaxy 16," a telecommunications satellite in "geostationary" orbit that all NPR stations use.

"Geostationary," also popularly referred to as "geosynchronous," means that the satellite orbits the Earth in sync with the Earth's rotation...about 6800 MPH. That's pretty fast, but the key is that it's the SAME speed for both. So from our perspective here on Earth, the satellite just floats there, not moving, over 22,000 miles up in the sky! In Galaxy 16's case, the satellite is at 99.0 degrees west longitude, meaning it's fixed above a point on the equator over the Pacific Ocean, about 500 miles west of the Galapagos Islands (near Ecuador).

In general, geostationary orbits work great for communications satellites like for NPR, but there's a catch: twice a year there are a few days when, the Sun appears to pass right "behind" the satellite for a few minutes each day. The Sun puts out so much energy on ALL frequencies that it completely swamps the satellite's own signal, so we lose all NPR, BBC and other satellite programming.

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