Tag: Electronic engineering

Now I’m The IT Guy

snapshot_000DC5D4C863_20150221162928When I started my studio project I had no idea I’d become “the IT guy.” Everything is digital. Nothing is analog… except me.

The good news is I like this stuff, but this is way deeper in than I’ve ever been. I’ve got servers and a bunch of other single purpose computers, like my switcher and the modem that allows me to send HD video over the Internet.

Nearly every device is sharing with every other device. Files need to be available no matter where I am or they are.

I poked holes in my firewall and forwarded ports to allow the outside world to communicate directly with some of my gear. It’s not without danger. Miscreants are robotically probing for weaknesses in systems like mine 24/7.

In the analog days video and audio were like water flowing through pipes. You could cut the pipe at any point and split it or meter it.

Not today.

The flow is more orderly and intensely complex. Data doesn’t flow, it’s routed. As you might imagine, 1080i video consumes lots of data. Every hour my studio is feeding it sends around 5Gb of data.

Packets are flying through my network at breakneck speed, but it’s still the bottleneck of my system… of most complex networks. Optimization is everything. I’m working with vendors’ experts who know their systems to tweak every last bit of performance.

This isn’t a never ending project, is it?

It’s Starting To Look Like A Studio

studio 5E

“Take Doppler to piddle, but stop in the garage before you come upstairs.” Helaine wanted me to see what she’d accomplished while I was gone.

Holy crap. It’s a studio!

It took lots of work on her part preparing and painting the wall. The electrician removed an outlet right in the middle. Helaine patched and sanded before applying two coats of Behr Sparkling Apple.

It looks amazing. She’s amazing.

Two backlights are overhead. The key lights are on stands. They’ll be held in place with sandbags. That’s how it’s done in real studios.

There are mounts and power for monitors and a clock hung from a beam.

Cox came and installed service. I’m told I need 6-8 mbps for high quality, low latency, HD video. I’ve got triple that.

Most of the equipment is still enroute. I’d like to set it up next weekend, if possible. I’m itching to get started.

Little things keep popping up. We’re starting from scratch. I ordered a charger, 8 AA NiMh batteries, a few 25 foot HDMI cables and light meter, tonight.

In a few weeks my garage will be a chroma key driven sound stage. It’s for work. It’s a toy. This is a very cool project.

Wireless IFB On The Cheap

The producer, director and a few others have the ability to break the flow and speak to you. It can be very helpful. It can be very confusing. I’ve heard both.

ifb-replacement

Equipping my new studio sometimes gets frustrating. I want to make the right decision. Facts aren’t always available.

The best example is a wireless IFB system. IFB stands for “Interrupt Feedback” or “Interrupt Foldback.” It’s that earpiece TV people wear.

Your earpiece plays what’s on TV. The producer, director and a few others have the ability to break the flow and speak to you. It can be very helpful. It can be very confusing. I’ve heard both.

IFB systems are expensive. I didn’t like that idea. They’re also bulky. Clipped to your pants waistband an IFB receiver adds extra girth when wearing a suit.

I think I’ve found a solution. It’s a Bluetooth transmitter and receiver. Though both are made by the same manufacturer and look the same, they’re not normally marketed as a pair. They are reasonably cheap.

I might be able to create a wireless IFB for under $60. That’s hundreds, possibly thousands, of dollars saved!

Even better the unit is tiny. The receiver at the top of this entry is 2.5″ long, 1″ wide and around .25″ thick. Other than coins there’s nothing in your pocket smaller.

It won’t work in a studio with more than one person. Bluetooth adds a slight but noticeable delay. A ‘live’ person would echo.

In my situation an extra 1/30 or 1/15 second wait to hear the ‘distant’ anchor is inconsequential.

This solution seems too good to be true. It very well might be, but a quick test tonight worked. Call me hopeful.

My Opinion Has Changed

Sony

A week or so ago I smiled mischievously as the hack against Sony was revealed. After a little more thought my opinion has changed. And, I guess I should add, I understand what happens when private emails go public.

For totally blameless Sony employees this has been a public undressing. Every detail of their personal life that crossed their work computer was laid bare.

Every number associated with their existence will have to be changed!

That’s a very 21st Century concept most of us don’t understand. Once something is in Google, forget it being forgotten!

Some of the Sony emails are brutal, but not unexpected. We all do a little of that with our friends (though probably not the Obama stuff–definitely not).

There’s no way Amy Pascal can survive. Amy: I said the same thing about Roger Goodell.

Sony’s lawyers are trying to quash the publication of any new details. God bless them if that works. Experience says it’s a fool’s errand.

Comcast And AT&T: Gobble, Gobble, Gobble

Comcast wishes to become a vertically integrated behemoth. They will dictate programming and technology because their fingers are in every pie.

Even today they double dip, charging Netflix for services I’m already paying for. That’s what monopolies do! How can you say no to the company that stands between you and your customers?

New Haven Comcast officeComcast is in the process of swallowing Time-Warner. AT&T has just announced they’re purchasing DirecTV. Maybe I just haven’t looked closely enough, but where is the benefit to citizens?

The biggest trend in American business over the past few decades has been consolidation. Much of it is subject to regulatory approval. It should be subject to regulatory scrutiny. That part seems sorely lacking.

Comcast wishes to become a vertically integrated behemoth. They will dictate programming and technology because their fingers are in every pie.

Even today they double dip, charging Netflix for services I’m already paying for. That’s what monopolies do! How can you say no to the company that stands between you and your customers?

Comcast as every incentive to do more of the same, protecting their legacy businesses through the terms they offer consumers.

Will programming and distribution deals be structured, as many are now, to protect Comcast’s cable TV business? Why do I even ask?

There was a time in America when bigger was better. Charles Erwin Wilson, nominee for Secretary of Defense in the early 1950’s famously tried to hold onto his GM stock while in office&#185.

Because for years I thought what was good for our country was good for General Motors, and vice versa.

att_logoAnd maybe, sixty years ago, it was. Employment scaled up as company’s did.

Is there anyone who actually believes the Comcast or AT&T acquisitions will have a positive outcome for America? More choice? More employment? More investment? Better technology?

“This compelling and complementary combination will bring significant benefits to all consumers, shareholders and DIRECTV employees,” said Mike White, president and CEO of DIRECTV. “U.S. consumers will have access to a more competitive bundle; shareholders will benefit from the enhanced value of the combined company; and employees will have the advantage of being part of a stronger, more competitive company, well positioned to meet the evolving video and broadband needs of the 21st century marketplace.” – AT&T press release

The important part is there in the last sentence:

a stronger, more competitive company, well positioned

We’re already dealing with companies treading very close to the anti-trust line. Take the bundling of cable TV services, where I have to buy loads of channels I don’t want to get the ones I do.

Typically, the “tied” product may be a less desirable one that the buyer might not purchase unless required to do so, or may prefer to get from a different seller. If the seller offering the tied products has sufficient market power in the “tying” product, these arrangements can violate the antitrust laws. – Federal Trade Commission

The system is being gamed and these mergers and acquisitions will only make things worse. It’s time to put a stop to it.

&#185 – He sold his stock before his appointment, but after his confirmation hearing.

Math, Doppler And The Missing Jetliner

mh370-tracksI just finished reading some technical data from Inmarsat and Ministry of Transport Malaysia concerning the analysis of satellite data transmissions from MH370. It’s this data that’s shifted the searchers from MH370’s planned route to a tract in the Southern Indian Ocean well west of Australia–nearly the opposite direction expected!

It is a brilliantly concocted method to get usable information from what should have been meaningless housekeeping transmissions.

Radio signals travel at the speed of light. If we know how long those signals take to go satellite-to-plane (or vice versa) we can start doing calculations and find the distance between the two.

Inmarsat was then able to calculate the range of the aircraft from the satellite, and the time it took the signal to be sent and received, to generate two arcs of possible positions – a northern and a southern corridor.

mh370 doppler shiftAs you probably know the northern track was thrown out. But why? That’s where the plane should have been flying. It was the most logical direction.

Enter Doppler!

Because the satellite and plane were both moving, their radio waves were subject to Doppler shift. This is an expected part of satellite work and equipment to compensate for it is built into the system.

The Inmarsat technique analysed the difference between the frequency that the ground station expected to receive and the one actually measured, known as the Burst Frequency Offset.

mh370 data versus tracksBecause the satellite wasn’t at the midpoint of the two project tracks, the expected northbound offset or shift was different than the southbound shift. What was actually seen only matched the southern track.

Depending on the plane’s speed the same Doppler shift could indicate slightly different positions. Unfortunately, that’s an unknown. It’s a good guess to estimate 400-450 knots. That’s why the area now being searched isn’t a single point, but a larger area.

Obviously, the plane hasn’t been found, there’s still no real explanation for what went wrong. However, this clever use of math helps bring those looking one step closer.

I know this is somewhat complex. I’m not 100% sure my explanation will be clear to everyone. Questions are welcome.

The Cellphone’s Mortal Enemy: Lint!

Errand Day in Irvine! My chance to score daddy points with Stef. I took her car for a smog test, oil change and wiper blades.

My phone beeped twice as I took it from its charging stand. “8%,” a large notice on the screen read. This was a problem.

stef's-car-on--a-liftBy the time Stef’s car was on the lift the phone had died entirely!

I plugged it in. Nothing.

What about a cellphone free weekend. I could handle that, right?

Who am I kidding?

My phone is an HTC One. I’d get one again in a second. It’s a wonderful phone with a solid build and battery that lasts through a full day!

Well… usually.

The AT&T store is five minutes from here. Not their job! They sent me to the central repair facility near the 405.

I handed my phone across the counter. He held it up to the light and looked at the charging port. His stare was intense.

“No water,” I offered.

They always look for water as a way to get off the hook. A few seconds later he was pushing a cloth across the port’s connectors.

“Maybe a little lint,” he said, though he didn’t sound totally convinced. “Let me put it on the charger for a few minutes.”

I went for coffee and came back to find the phone turned on with a 3% charge. It was back from the dead and slowly building its strength.

Lint? Lint did this? Or did he just get lucky?

Why Cell Phones Don’t Work (Well) From The Air

cell phone tower antennaSome people are wondering why no one has been able to track MH370 through cellphone data. We know the NSA has been storing cell metadata for tracking. Isn’t this the same scenario?

A brief lesson in physics is needed. Don’t be scared. No math.

Think of an antenna as the launching point for radio waves. If the antenna is a single element, those radio waves will depart at equal levels in all directions. A car’s AM/FM whip antenna is an example of this.

Remember the days of rooftop TV antennas? They had many elements. That wasn’t just to make them more unsightly!

tv-antennaAntennas may also include reflective or directive elements or surfaces not connected to the transmitter or receiver, such as parasitic elements, parabolic reflectors or horns, which serve to direct the radio waves into a beam or other desired radiation pattern. – Wikipedia

That’s exactly what’s going on at the cell site.

cellair-aWhy bother sending signals where they’re wasted? With a directional antenna you can redirect power to where it’s needed. In most cases that means concentrating nearly all a cell tower’s power parallel or slightly down toward the ground. Pointing down slightly is necessary because of the Earth’s natural curve.

The extra gain in the antennas beams, used to increase signal strength to us on the ground, is taken from what would radiate upwards!

Radiation Pattern of a Cell Tower AntennaI’m sure I’m not the only person to ever power up a cellphone in flight to see if I could hit a tower. I’ve never been successful. This is why.