Industrial Security
Industrial Ethernet
Data Centers
Broadcast AV
Belden News
Blog Home
Blog Category: Broadcast AV

Posted by: Steve Lampen on September 24, 2013

It wasn't that long ago that the ultimate of anything was "handmade". Whether it's a Rolls-Royce or a piece of furniture, the best was "handmade".

But then came our high-tech world with surface-mount components or large-scale integration. Clearly, these cannot be made by hand. Just removing and replacing a surface-mount chip is at the very limit of human agility. Making the chip itself?

Forget it. Only machines can make the chip. Only machines can place it on the board in exactly the right place, especially if we say 'place one every second'. The idea of John Henry beating the rail-laying machine was heroic and romantic. Let's see him assemble a cellphone. In some ways accepting this is pretty sad.

Read More >>


Comments (0) Post a Comment

Blog Category: Broadcast AV

Posted by: Steve Lampen on September 19, 2013

On Monday, April 28, 1969, I walked into the Hilton Hotel in downtown Los Angeles on Figueroa Street. The hotel is still there, but now part of another chain. I was a very excited 18-year old. I could barely contain myself because I was about to enter my very first convention of the Audio Engineering Society. Was this my first convention ever?

No, I had been attending tradeshows and conventions for a few years. The key one was Wescon, they were way ahead of their time and gave each attendee a "credit card" embossed with your name and address. I took it to every booth I could and, at age 14, the mail started pouring in. My parents were mystified. I actually filled up a three drawer file cabinet with all that literature, arranged in alphabetical order. (Some of you have suspected, now confirmed, that I was seriously OCD back then. I haven't improved much.)

Read More >>


Comments (1)
Post a Comment

Blog Category: Broadcast AV

Posted by: Steve Lampen on September 12, 2013

United Airlines loves me. I think I know almost every trick about how to get from Point A to Point B. I am also the king of "Plan B", otherwise known as what to do when things go wrong.

I am pretty lucky, really. For instance, you know about Asiana 214 that crashed in San Francisco? I was on the NEXT PLANE preparing to land. Whew! And, as I approach my 2 millionth mile with United, that is not my first brush with mortality. If you see me in person, ask about the time I drove off a cliff (in my company car) and walked away without a scratch. I must be charmed.

But does this stop me? No! This is my dream job. The only real problem is that I am not at home as much as Debra, my wife, would like. If you ever meet her, you can comfort and commiserate with her. But eventually, I will be home ALL THE TIME, and she's not too excited about that either. In the meanwhile, I travel. Hello from Sao Paulo, Brazil, where I write this. Did you know Brazil was named after a tree? It made a beautiful red dye so it was almost cut down to extinction. I saw one today.They are now protected, of course.

Read More >>

Tags: Trade Shows

Comments (1)
Post a Comment

Blog Category: Broadcast AV

Posted by: Steve Lampen on September 05, 2013

I'm a huge fan of a British TV series from the 1960's called "The Prisoner". It starred Patrick McGoohan (reprising his 'Secret Agent' role) who is captured and sent to this strange land where they try and break him. It was only 13 episodes long and was seen as a summer replacement series in the USA.

The location footage for that show was filmed at a resort on the northern Welsh coast called "Portmeirion". I have visited there many times. Once I went by train from London to Portmeirion, which was one of the strangest trips I have ever taken. The train stops in the middle of Wales at a train station literally in the middle of nowhere. I was told it is the only train station NOT accessible by car in the entire British Isles. The reason for it is that the Welsh railroad uses a different rail gage, so the British trains cannot go there. You get off one train and on to another, just because the gage changes.

Read More >>

Tags: Audio, Video, SMPTE

Comments (0) Post a Comment

Blog Category: Broadcast AV

Posted by: Steve Lampen on August 29, 2013

We've spent a whole month taking about the "digital cliff", about measuring bandwidth, wavelength and critical distance. And we've talked about our "safe distance" table based on the formulas in the HD standard (SMPTE 292M). Use those safe numbers and you don't have to think about anything, you don't have to measure anything. Just put on some connectors and plug it in. If you get failures at these short distance, you have something very wrong, a lot more wrong than a cable a bit too long. Is everything intended for HD? Tested by each manufacturer to AT LEAST 2.25 GHz? (Last time I mentioned how one project was stymied by using analog 75 ohm terminators!)

Read More >>


Comments (0) Post a Comment

Blog Category: Broadcast AV

Posted by: Steve Lampen on August 22, 2013

For the last couple of weeks we've been talking about the "digital cliff" where signals no longer work. Check out the previous installments about bandwidth, wavelength and critical distance (Part 1 and Part 2).

The critical distance is the length at which it is important to know the impedance of the cable, where the cable is now a "transmission line". For signals like professional high-definition video (SMPTE 292M standard), the critical distance is a little over ONE INCH. That simply means that everything is critical, cable connectors, patch panels, patch cords, adaptors.....everything in that passive line between boxes. But that still doesn't tell you where the cliff is.

Read More >>


Comments (0) Post a Comment

Blog Category: Broadcast AV

Posted by: Steve Lampen on August 14, 2013

We've been talking about digital signals and their limitations. The first step is to ascertain the bandwidth of your signal. Our example in Tales of the Cliff - Part 1 was RS-422 which has a bandwidth of 10 MHz.

Once you know the bandwidth, you can calculate the wavelength. 300 million divided by that frequency gives you the wavelength in meters. 300 million divided by 10 million equals 30 meters (about 100 feet). The critical distance is not a full wavelength but a quarter wavelength. (Think about a sine wave. Where is at its maximum effect? A quarter of a wavelength.)

So a quarter of 100 ft. is around 25 feet. And what that means is that, below 25 feet, you can use almost anything to carry RS-422. After 25 feet, it is a "transmission line" and requires that you match the impedance of the source and destination devices with the impedance of the cable. For RS-422, this impedance of the devices is 100 ohms, so the cable will also be 100 ohms. When you put connectors on your RS-422 cable (15-pin sub-D, most commonly) are they 100 ohms? No, they aren't. But it doesn't matter because they are less than 25 feet long. So you can use any connector. But that doesn't tell you the MAXIMUM distance you can go.

Read More >>


Comments (0) Post a Comment

Blog Category: Broadcast AV

Posted by: Steve Lampen on August 08, 2013

I've been having some interesting conversations with customers about the "digital cliff". How to find it....and how to avoid it.

The digital cliff, as you probably already know, is the point where a digital signal cannot be resolved by a receiving chip. Most people assume this is because the cable is too long, in other words the signal has attenuated beyond a point of recovery. But that's only one of a dozen factors that can affect digital signals.

Most people also may assume we're talking about digital video, like HD or 3G. But there's a digital cliff for any digital signal, including for digital audio. There's a cliff for data cables. There's a cliff for RS-232, RS-422, RS-485....and so on.

Read More >>


Comments (0) Post a Comment

Follow Us

Subscribe
Broadcast AV
RSS Feed
Broadcast AV
Email Notifications

Search
Broadcast AV Blog
All Belden Blogs


Stay Informed