Longtime Engineer's Corner readers know that we've had, well, "issues" with the STL or "Studio/Transmitter Link" for our 88.1FM signal in Providence. The STL is what carries the audio from our studios in downtown Providence to the transmitter/tower at the Wheeler Farm in Seekonk.
Now a couple weeks ago we revealed that half of a new wireless microwave STL was installed, and that the other half would be installed soon. Today, we fired it up for the first time and the results were gratifyingly positive!
In many ways, this is an even bigger deal; 102.7 had a hefty vent fan system that could move a lot of air. Sure, if the air outside was hot, it means the air inside was hot, too. Usually you can't cool a room using outside air below about +10F degrees above outside air temps. So if it's 90F outside, it's 100 to 105F inside...ugh!
And at 88.1, we didn't really have even that. The transmitter site is an 8x10ft shed with a single 12 inch desk fan blowing air out one of the wall vents, and no insulation whatsoever on the walls or ceiling. Temps routinely broke 120F inside, even when it was only 70 to 80F outside.
The morning of April 30th saw several odd "dropouts" in the audio on 88.1FM, usually lasting 5 to 8 seconds each, happening as often as 2 or 3 times a minute, but more commonly once every 10 to 15 minutes.
There was also an odd "repeating audio" effect some people noticed, when the audio came back.
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!
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.
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.
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.
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!
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.
Air conditioning. Cool heaven for those who have it, blazing hell for those who don't. It didn't used to be terribly common in broadcast engineering, but it's become moreso in the last ten years. The reason is that, more and more, audio processors, RDS encoders, audio encoders/decoders, studio/transmitter links, remote control systems, and even the transmitters themselves, have all become increasingly "computer-like" with IC's, hard disk drives, power supplies, electrolytic capacitors and the like. All things that fail quickly when operated in temperatures above 80 or so, and the warmer it gets, the faster they fail!