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Newsletter Issue 5

Inside this issue:

Comrex Comments

by Lynn Distler
President, Comrex Corporation

About a year ago, we received a call from Jimmy Buffett's producer with the news that they were using our Vector POTS codec to send live audio from their road shows back to the radiomargaritaville.com web server. At the time, we thought that was a cool although somewhat unique application. But then we started to notice more .coms on the box labels leaving our building.

A couple of months ago, I was reading a column by Holland Cooke of McVay Media in TALKERS MAGAZINE entitled "You dot com, or else." Cooke tells his talk host readership: "Seen those compact broadcast-anywhere-on-a-regular-phone-line boxes Comrex advertises here in TALKERS? I'll bet that in 2000, they sell more of 'em to people whose work is heard on the Internet than people whose work is only heard on radio."

While Mr. Cooke might be jumping the gun a bit on this prediction, we certainly are seeing a trend in this direction. In this issue, we profile a couple of our .com customers. eYada & Westwind Media are good examples of what is becoming mainstream. Meanwhile, Comrex continues to do its job of bringing live, high quality audio into the studio, no matter whether distribution is over the airwaves or through the web.

"The more things change...."

ISDN via satellite - Portable terminals have come a long way!

There are new players in the portable satellite uplink business. Thrane & Thrane from Denmark and Nera from Norway are offering portable satellite phones that can simulate a 64 kb/s BRI ISDN channel. These phones use Inmarsat's Global Area Network Service (M4) at a cost of roughly $8.00 USD per minute and the satphones run around $10K. This may seem pricey, but they might be a lifesaver for broadcasters that have really tough jobs to do! (Ever needed to deliver a remote from a cruise ship?)

ABC Radio news recently used these terminals for live news reports from Israel and India where they were unable to get ISDN land lines on short notice. They tested both terminals and found that the Comrex Euro-Nexus worked well with either one.

It is important to remember that these uplink terminals have an "S/T" interface, so a codec or terminal adapter that presents a "U" interface (like the Nexus and most US codecs) can't be used. Our new Matrix codec will also be a perfect match, since it supports the EURO S/T standard, and the ISO/MPEG Layer III featured in the Matrix will deliver 15 kHz on the available 64 kb/s channel.

Matrix details later on in this issue.

Tailgate test of the Nera WorldCommunicator The photo on the right shows a "tailgate" test of the Nera WorldCommunicator recently performed at Comrex. The Nera was loaned to Comrex by GMPCS, a US dealer. Setup took only a few minutes. We then called the Comrex ISDN test line from the EuroNexus, establishing a 64 kb/s link from outside our front door, up to the AOR-W satellite, back down to French Telecom and finally to the Nexus in our demo rack via ISDN. We had a crystal-clear link for the 10 minute call, which was ended by simply pressing the HANG-UP key on the Euro Nexus.

Note that the delay time through the satellite system is around a half second each way, so the normal 6 mS G.722 delay is considerably lengthened. A mix-minus return feed will be necessary. Use of audio coding systems with longer delay times will obviously require more caution.

New Matrix POTS/ISDN/GSM Codec Wins 2 Awards at NAB 2000

Matrix Portable and Matrix Rackmount

We try to provide the readers of this newsletter with useful information and to avoid excessive bragging; however, we are REALLY proud of our new Matrix codec and can't help doing some shameless boasting! At the recent NAB show, the Matrix was the recipient of Radio World's "Cool Stuff Award" and also BE Radio's "Pick Hit" award. The winners of these awards are chosen by panels of judges consisting of radio professionals and are indicative of true industry choices.

optional GSM module, optional battery kit and phone not included

Shown at right with optional  GSM module, optional battery kit and phone (not included)

Here are some key Matrix features:

  • The Matrix is a versatile, lightweight codec with the ability to send high quality, full duplex audio over POTS, ISDN or wireless service. There's nothing remotely like it. 
  • The basic unit delivers 15 kHz audio on a single POTS line and is compatible with the popular Vector and HotLine POTS codecs.
  • A "store and forward" feature permits audio cuts to be sent in non-real time over POTS or wireless service. Useful when a circuit won't sustain adequate or stable enough data rates for real time codec transmission.
  • Can be used in Plain Telephone Mode for easy connection of microphone and headphones to a POTS line.
  • Two inputs (one is mic/line switchable), one headphone output and one auxiliary output are featured.
  • Optional modules may be purchased that slide into the bottom of the Matrix. These modules offer connections to different types of circuits.
  • An ISDN module converts the Matrix into a powerful ISDN codec, including ISO/MPEG Layer III, G.722 and Turbo G.722. This gives the user maximum industry compatibility as well as the ability to transmit 15 kHz at 64 kb/s or to deliver a very low delay 15 kHz at 128 kb/s.
  • A different Matrix accessory includes a pcmcia slot enabling connection to a GSM wireless phone.
  • An optional  battery pack is available for the Matrix.

Vectors on the Internet

One given in broadcasting is that not all programming occurs in the studio. Cool stuff happens in remote locations. Regardless of whether you're a traditional broadcaster airing audio on the radio or a website that offers live audio content, Comrex plays an important role in program contribution. Here are two examples of how our codecs are being used for internet applications.

eYada.com is an exciting website that delivers live talk shows 24/7 on the net. Vector POTS codecs have played a critical part in their programming. Most of eYada's shows are generated in their main New York City studios, but eYada's Vice President and Director of Programming, Dave Herman, informed us that virtually all audio contributions from other sites are delivered via Vectors. Herman states, "They're fabulous! We've done shows in Australia and Victoria, B.C. We air daily programs from LA, San Jose and Vegas. The Vectors deliver virtually all off site shows, whether they are daily programs or one shot remotes." Herman indicated that their Vectors allow eYada ultimate flexibility to broadcast from anywhere, enabling them to produce compelling programs.

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Westwind Media provides content solutions to the internet community. They specialize in adding interest and depth to clients' sites with high quality streaming audio and video. Their customers include ivillage.com, Eritmo.com, BET.com, TheStreet.com, and BOL.com. Andrew Rosenburg, Director of Studio Engineering, states that Comrex Vector and HotLine POTS codecs are used to deliver live voice content from a remote site to the main Westwind studios, where the program is assembled and delivered to their clients websites at the highest possible quality for air. The POTS codecs are also used as back-up for their ISDN remotes. We found it interesting that these are the same types of applications traditional stations and networks have been doing on Comrex for decades!

Ask the Codec Answer Guy

Codec Answer GuyWe have assembled a collection of frequently asked codec questions some of which are presented here. For a complete list of the Answer Guy questions and answers, either give us a call or send us a completed reply card.

Q. Somewhere around the eighth inning of our last two baseball games, our Vector has "renegotiated," with a corresponding hole in our play-by-play.

A. The modem in your Vector (or HotLine) works by negotiating settings based on all kinds of electrical characteristics of the phone circuits through which your call is routed. After a couple of hours of use, those figures may change, and you might do yourself a favor by redialing the call during a break in programming. This isn't a hard-and-fast rule; just a suggestion that may save you some troubles. It is also a good idea to set a MaxRate for the modem. Further details below.

Q. How can I find out about upgrades for my Comrex unit?

A. Ask us! All upgrade information is now on our web site: www.comrex.com in the TechTips section. If you prefer, send the model names and serial numbers to us via fax (978-635-0401) or email (techies@comrex.com), along with your phone number, and we will let you know whether an upgrade is recommended.

Q. How can I get 33.6 kb/s modem connections?

A. Your goal should be to achieve the highest speed at which the modem operation will be stable. Since slower connect rates are more tolerant of errors, some judgement is required to hit the right spot. In fact, the Answer Guy is partial to speeds of 28.8 kb/s and lower, as all V.34+ modems seem to be more stable at those rates. Use the MaxRate to set a ceiling that works in your area. And ignore those Internet weenies who try to tell you that "faster is better." Sex and modems do have something in common...

TechTips: Connecting to a Sound Card

We are starting to get more calls from users who, for one reason or another, need to connect the audio inputs and outputs of Comrex codecs to computer sound cards. So we thought we'd outline some of the technical details here:

All sound cards are not equal, but most are similar. They typically send and receive audio over 3-conductor, 1/8" stereo mini plugs and have audio levels which are lower than those used for professional applications.

Most sound cards have two different input jacks, one for line level inputs and one for connections to a microphone. Under most circumstances, noise levels will be lower if you use the "line" level inputs. Many sound cards also have a pair of stereo outputs, one for powered speakers and another for unpowered speakers or headphones. Both of these outputs are usually ok, but there may be slightly less distortion on the "powered speaker" output.

Keep in mind that while most of our codecs are mono, computers by nature handle stereo audio. Therefore, accommodations will need to be made. We have published a detailed document that describes how to adapt mono codecs to stereo sound cards and also addresses the following issues:

¨ Dealing with the fact that codecs have balanced ins and outs and sound cards have unbalanced ins and outs.

¨ Coping with variability in levels between codecs and computers.

Plan: 3YK

Fred was our Y2K project manager. If you've left your bunker, you realize that life has continued pretty much as usual since January 1, 2000. This is no accident, but due to the tireless efforts of people like Fred.

Fred saw all this coming years ago. Knowing that it would be the subtleties of electronics, not stupid programming short-cuts that would bring the broadcasting world to its knees, he became an expert in the field of "component psychology." Don't chuckle! Electronic parts have feelings and anxieties, you know. And with the greatest of all technological calamities just around the corner, Fred spent the last few years studying the digital and analog pieces that make up Comrex products.

Digital stuff was quite easy, according to Fred. When you've only got two states, on and off, the only issues are in feeling jittery switching from one to the other. With proper visualization techniques ("feel the one, become the zero"), the circuitry can be trained to anticipate change and land with both feet.

Fred really earned his stripes with analog parts, though. Just think of it - transformers are in a state of flux, resistors resist, capacitors get all charged up, diodes do things one way.you get the idea. Who else would have faked out the nervous transformers by putting January, 2000 calendars on the wall while the TCB-1s were assembled? Or counseling that 100nF capacitor from jumping off the ledge and rupturing his dielectric. Or that unconventional herbal therapy (it's OK for resistors to smoke a little pot.).

All of this frankly and sadly cost Fred his personal life. By January, he just had nothing more to accomplish, and nowhere to go at night. That's why he volunteered for our Y3K project. He became so concerned that in another 1000 years there would be no component counselors that he offered to have himself frozen, and thawed out in time for the next big crisis. We already miss him, but as Comrex employees we'll keep a stiff upper lip (not as stiff as his, of course). We only have one big worry. And those of you who have worked in offices can easily appreciate our concern: What happens when someone eventually gets around to defrosting the office refrigerator?