Engineer's Corner

Engineer's Corner
1:11 pm
Thu April 10, 2014

TheEC: Heartbleed and Donations to RIPR

The big news in computing this week is Heartbleed, a serious security problem with secure websites.   Specifically, it's a two-year-old bug in the near-ubitiquous OpenSSL (Secure Socket Layer) protocol...most commonly recognized when there's a "https" (instead of "http") at the beginning of a website address.

It's a big problem, and I'll explain why in a second, but first I wanted to let everyone know that the RIPR donations website is secure and never was vulnerable to Heartbleed.   They use a hardware-based implementation of SSL, not OpenSSL.

So if you have donated or plan to donate to RIPR, you have nothing to worry about in regards to Heartbleed and that donation.  Whew!

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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
12:46 pm
Tue March 18, 2014

TheEC: $18 Million Dollar Typos

The RIPR AudioVault

  This time on The Engineer's Corner, I want to look back three weeks ago, and look back over fifty years ago.  And how little typos can have a big impact when it comes to engineering.

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Engineer's Corner
5:00 pm
Sun February 23, 2014

TheEC: FullChannel Proves Imitation is the Highest Form of Flattery

FullChannel Engineer: Jamie Griffin
Credit FullChannel

Our good friends at FullChannel cable, available to residents of Barrington, Warren and Bristol, are not only nice enough to put RIPR's audio on channel 799.   But also their engineer, Jamie Griffin, has started his own "Engineer's Corner" email newsletter for cable TV folks.

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Engineer's Corner
5:08 pm
Mon February 3, 2014

TheEC: Prison Radio

Sony SRF-39FP
Credit Museum of Everyday Objects

A recent article in the New Yorker about radio in prison piqued my interest.  Besides providing a window into a world that many of us know little or nothing about, it caught my eye that these Sony SRF-39FP ("FP" for "Federal Prison") radios are actually remarkably good receivers.  

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Engineer's Corner
10:08 pm
Mon January 27, 2014

TheEC: 88.1 Studio/Transmitter Link

Screenshot of the Comrex BRIC Link web GUI
Credit Aaron Read

In light of ongoing issues with the Studio/Transmitter Link (STL) for WELH 88.1, we have implemented a new STL  schema.   If you heard a lot of odd audio dropouts on 88.1 today, that was the reason.

The good news is that we should have a pretty good temporary solution in place, and a solid path for a permanent solution is on the horizon (tentatively scheduled for mid-March).   Best of all, I was able to put in a new(er) Orban Optimod 8100A audio processor to replace the less-capable Inovonics DAVID-III.  There's a little sibilance still, so I need to tweak the settings.  But overall the sound should be much louder, fuller, and more consistent.

Read on for more details...

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Engineer's Corner
11:49 am
Tue January 21, 2014

TheEC: Browser Extensions that Spy on You

Credit howtogeek.com

Taking a break from broadcast engineering this time on TheEC, and instead we'll look at the other side of my job: computers.   In particular, here's a heads-up to a recent story that's lit-up the geekier realms of the internet, but may not have percolated to your inbox just yet.  It has to do with BROWSER EXTENSIONS and how they might or might not...probably might...be spying on you.

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Engineer's Corner
4:58 pm
Fri January 3, 2014

TheEC: Digital "Chirps" on 88.1

PCAU cards. Left is WELH's Main STL encoder. Right is an unused spare.
Credit Aaron Read / RIPR

UPDATE (Jan.10):  Verizon sent a trio of techs today to examine the Digital Lines.  They found a splice point on a pole near the Wheeler Farm end of the circuit where water had gotten past the weatherproofing.  The splice was re-done, with fresh (and better) weatherproofing sealant applied, and a weather box placed around it.

That's likely the culprit here: the problems started during the snowstorm, so probably water got in there and expanded/contracted repeatedly as the water froze and melted.  That expansion wreaks havoc with (relatively) fragile copper telco wiring.

As of 3pm we are back on our main STL.  We've noticed the volume levels seemed to have changed somewhat with this repair, too, so we're still tweaking things.

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ORIGINAL POST (Jan.3): Ever since the hefty snowstorm and extreme cold on Thursday night, our 88.1 signal in Providence has been experiencing "digital chirps" now and then.  

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Engineer's Corner
4:50 pm
Thu November 21, 2013

TheEC: 1290AM Heard in Norway

Longwire antenna used to successfully receive 1290AM in southwestern Norway.
Credit Arild Skalmeraas

We've talked in the past about skywave propagation, but it's cool when you heard about real-world examples of it.   Recently I've gotten several emails from "DX'ers" (Distant Reception enthusiasts) in Europe saying they've been able to hear Latino Public Radio on 1290AM all the way across the Atlantic!   

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Engineer's Corner
1:43 pm
Tue November 12, 2013

TheEC: 91.5 is Back On the Air

From top to bottom, Bext LEX30 transmitter, Dayton 210 FM receiver tuned to 102.7 to get programming to feed the transmitter, and Inovonics 631 FM receiver to monitor 91.5 on the speakers above.
Credit Aaron Read

As of Tuesday November 12th, WCVY is back on the air in limited fashion.   As you know, WCVY suffered catastrophic damage to its equipment and facility from a roof leak during a thunderstorm in August.   The entire space had to be gutted to the concrete walls, and new electrical wiring and drywall installed.  Much of the transmitter gear either took direct water damage (e.g. electricity shorting out) or took indirect water damage (e.g. rust and other corrosion), and eventually a lot of it failed completely.

We have put a temporary setup in place with a donated 30 watt transmitter on loan (with the antenna array's gain factor of 2.1, it's really more like 63 watts of Effective Radiated Power), and a special radio that's tuned to 102.7FM (there's a high-gain FM antenna on the rooftop tower) and puts out the composite signal directly into the new transmitter.   This effectively makes 91.5 into a "repeater" of 102.7FM.

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