Journal Broadcast’s Engineering Executive Takes High-Profile Role in DAB Test Process
MILWAUKEE Andy Laird, newly promoted to vice president of radio engineering for the Journal Broadcast Group, oversees technical operations for 36 radio stations. The 57-year-old has had a varied career, starting as a musician and disc jockey in Illinois, progressing to station engineer, to group engineer and running his own studio design/construct business.
Since 1991, Laird has been involved in the development of digital audio broadcasting, serving in various capacities as a volunteer for the National Radio Systems Committee, where he now chairs the Test Procedures Working Group of the DAB Subcommittee.
His group is developing test procedures it hopes will prove, once and for all, whether in-band, on-channel DAB is superior to analog, and whether the United States should adopt IBOC as its digital broadcasting standard after a decade of debate.
Laird spoke to RW News Editor/Washington Bureau Chief Leslie Stimson about his career and pressing technical issues affecting radio.
RW: Your test procedures group is developing AM IBOC test criteria now?
Laird: Yes, in fact we have a very good broad outline of how we think the AM system will be tested. iBiquity has been busy getting their FM testing running smoothly. The laboratory test bed is finished. …
Meanwhile the issues of the field-testing of the FM system have also been de-bugged. We’re hearing now that issues that have come up with the test vans have been solved. iBiquity has been very open to discuss the difficulties of getting everything running properly in a repeatable manner. …
The NRSC has two paid observers overseeing the data collection process in the vans. Stan Salek of Hammett and Edison is overseeing the van process in the west, and in the east our observer is Alan Rosner of Denny and Associates. (Note: Tom Keller is the NRSC observer for the lab tests. iBiquity hopes to complete FM field-testing before the NAB2001 show and begin AM immediately after.)
RW: When would you have the AM test criteria to iBiquity?
Laird: Our goal would be to have this complete and approved by the NRSC (meeting) at or before the convention.
RW: Was it a surprise to hear it would take iBiquity several months to integrate the PAC compression algorithm into its system?
Laird: No, it’s a hardware issue, mostly. The important thing to understand is that it’s very possible to test all the waveforms independent of what the compression algorithm is.
In this IBOC system, you can determine how rugged the system is in terms of multipath, interference and compatibility and its effect on the host station and on adjacent stations, because the transmitted waveform is the same. It doesn’t matter what compression algorithm is used. …
The thing that will impact PAC or AAC will be absolute quality and we will spot check to make sure that, in changing the algorithm, there hasn’t been a change in some aspect of the system. But if we confirm that nothing has changed, great. If we find a difference, than that part of the test will have to be re-done.
RW: Given all of this, when do you think all of the testing and the evaluation of the material would be completed?
Laird: IBiquity is saying they should have their integration done, and ready to begin quality tests in the fall, probably 4th quarter. We’ll begin evaluations when we get data from the Advanced Television Technology Center, an independent organization hired by iBiquity to perform lab and field testing. (Field tests are being conducted using iBiquity vans and employees, with oversight from ATTC and NRSC personnel in the vehicles.)
RW: What are the quality tests?
Laird: The absolute: how high-fi is it? How does it sound unimpaired? What we’re able to do is the impairment testing.
RW: What it sounds like when it’s hit by interference?
Laird: Exactly, and the compatibility testing now.
RW: Are you also able to do coverage tests now? Some broadcasters have had questions about whether they’d still have the coverage area with digital that they do now.
Laird: Yes, that is also part of the waveform test.
RW: IBiquity predicts its manufacturing partners would have receivers in the marketplace in late 2002 to early 2003. On the transmission side, some manufacturers are calling their equipment “IBOC-compatible” now, before there’s a standard. How is that possible?
Laird: I believe iBiquity has put the transmitted waveform to bed. … Therefore, receiver manufacturers and transmitter manufacturers know what it’s going to take to transmit the waveform, even though it may be a couple of years before they have to.
The same would be true for receiver manufacturers. They have a pretty good idea of what it’s going to take to receive the waveform.
RW: How does the waveform affect implementation costs?
Laird: It has an impact on power consumption and cost of the transmitter. The waveform that the final IBOC system creates and the ability of a manufacturer to come up with feed-forward processing to null out distortions of the power amplifier of the transmitter will have a real impact on implementation cost … (n other words) how easily the waveform transmits … or how demanding it is on the on the transmitting facility.
RW: One transmitter manufacturer a while back told us his company had figured out what the power increments would be for an FM IBOC transmitter, but not for AM yet, and that the crest factor is critical.
Laird: Power levels will change: say you have a 20 kW transmitter, depending on the crest factor, (which) will determine how that new transmitter has to be designed and how much head room or spare power capacity that transmitter has to have, to be able to transmit it.
You may wind up having a transmitter that puts out an average of 20 kW but it takes a 200 kW transmitter to do it without distorting it. Headroom – to not destroy the digital waveform – it has to be shot out of the antenna like it was put into the transmitter. In essence, it has to be very linear. Or, you have to understand the non-linearities and be able to correct them and have the corrections be stable.
RW: How can stations handle the inherent delay in iBiquity’s system? For instance, an engineer at an AM station recently expressed concern to us about the delay for remotes and other live events. What do you tell him?
Laird: You’ll have to have some kind of IFB, a real-time feedback to your remote location. Interruptible foldback. Maybe you make use of an SCA channel on your FM station that is transmitting the program real-time out to your remote site. That’s one way of doing it.
But it does bring up an interesting thing: what about a station that does real-time sports? And how are we going to deal with a football game in a stadium where people are listening specifically…
RW: In the stadium listening to a portable radio?
Laird: Yes, and the game is five seconds behind what you see on the field. How do you deal with that? That’s just something we are going to face in the broadcast business. …
I appreciate the fact that they’ve examined everything and optimized it. The decisions they’ve made are not arbitrary.
RW: What are you looking for at Journal Broadcast Group as far as planning capital expenditures for IBOC?
Laird: Being ready for IBOC is a major component in our planning. All of the facilities we’re remodeling, we’re addressing the infrastructures to take advantage of IBOC.
For instance, all the new studios are digital: digital boards, digital networking. We are on the path to being able to deliver, in our newer facilities, an all-digital stream. Once we get from analog to digital, like a microphone, we’re working towards being able to deliver to an IBOC transmitter, in the digital mode, never going back to analog.
RW: How will you handle combining the analog and digital signals when you begin transmitting IBOC?
Laird: For our transmitter plants, in some cases we have fairly new stations that we’ve purchased that don’t have auxiliary transmitters. Perhaps what we do is we buy an all-digital transmitter for them, then we have the analog transmitter as a backup.
Meanwhile, we have some stations that have new analog transmitters that we sized to be able to take the filter loss when we combine digital into (them) with a second transmitter. We’ve been planning our transmitter plants to have about 15 percent extra oomph on the analog transmitter. … I believe they’re thinking about a 10-percent (power) loss on the FM for the hybrid system.
RW: How long will we be in the transition period, before radio goes all-digital and stations turn off their analog transmission?
Laird: I have no idea. I think one of the things that drives a faster transition is the success of satellite receivers (for Sirius Satellite Radio and XM Satellite Radio). …
It will be a digital receiver, whether terrestrial or satellite. Once you’ve optimized a receiver for digital, it might be digital on all bands.
RW: How far away is that?
Laird: The first generation of receivers, of course, will have the problem of compatibility between the two satellite systems. And IBOC is not ready, so it’s not designed into these. Hopefully, IBOC and compatibility between the two satellite companies will be in the second-generation receivers. We’re probably looking at 2003 for the second generation of digital receivers. …
It looks like there’s going to be an easy way to deal with the Perceptual Audio Coder for satellite radio and IBOC. Let’s say the PAC is built into the radio, adding the decoding front-end may not be that big a problem.
RW: You’ve been working on IBOC technology for so long, what would you say to those who believe IBOC technology will be surpassed by other technology, especially in the car?
Laird: No, as a delivery system, it will have applications beyond just getting nice-sounding audio to everybody.
RW: Yes, with devices such as personal digital assistants. But is IBOC happening too late?
Laird: I believe that we’re highly bandwidth-restricted. Finding the spectrum to do these things is really hard. If we have a pipe, there will be people wanting to use it. And pay broadcasters for it.
RW: What would you say to those who believe we can already do this with RDS?
Laird: It’s way too slow a baud rate. Not fast enough.
RW: IBiquity says it will be up to stations how much of their bandwidth to allocate to programming and how much to data. How would this affect FM subcarriers?
Laird: The NRSC is investigating the impact that implementation of IBOC might have on services like reading services, and they’ve been attending our meetings.
RW: Some would say the quality of FM subcarrier channels is not great, and anything would be an improvement. Is that fair?
Laird: It’s the whole thing about RDS data throughput. It’s like, “OK, that’s what we’ve got and we’re using it.” …
What we’re hoping for is that we don’t create more problems for existing SCAs. We don’t know what the impact is yet once it goes hybrid. Once it goes all-digital, then there’s no such thing as an analog SCA anymore. …
You can transmit a subcarrier that has a nice, clean space of its own within an FM station. It, like so many other reception issues with FM and AM, is receiver quality- dependent on what it sounds like – how well that receiver can separate the subcarrier from the main channel and from adjacent or second-adjacent interferers.
A lot of these receivers are shockingly poor. … There’s an amazing array of old-design stuff being used today. We’re trying to assess the impact on those.
RW: Now that there’s one company developing IBOC, how has this affected the test procedures?
Laird: We have been more specific about what we want to see. …
That was one thing we learned from the first procedure. We learned we needed to define what it is we were really trying to get. We’ve achieved that, I think, with coordination with our other subgroup, the evaluation working group, chaired by Dr. Don Messer.
RW: When does his group kick into high gear?
Laird: When the reports are delivered from the Advanced Television Technology Center. … As soon as we get data from ATTC we’ll begin the evaluations. The NRSC will weigh in with an opinion, if we can generate one, on the performance of this system to the FCC.
RW: Are you going to have enough data to make a decision? Before, the proponents turned in the data they wanted to, and the NRSC said it wasn’t sufficient to reach a conclusion.
Laird: … We’ve changed the thrust of our testing to be more subjectively focused. … Basically the tests in the past have used systems that were kind of based out of Europe, some standards for how to do subjective measurements.
We’re looking at other ways of doing this now that may be more efficient, allow larger samples. … That doesn’t mean we set aside pure lab measurements, but there has to be a substantial subjective component because these systems are designed to mask problems. … It’s important that we have subjective testing that looks at absolute quality along with the system delivered quality under normal world listening conditions. (The NRSC plans to have two listening groups, one comprising ” trained” listeners and another group of broadcast industry representatives.)
RW: Will consumers be able to tell the difference between IBOC and analog in the car?
Laird: I’ve been called a golden ear, and my personal opinion after riding around in proponents’ vans, to me the difference is startling.
First, there’s a huge difference in signal-to-noise ratio. I would argue that’s the largest flaw in broadcasting today is the interference levels and motion artifacts.
RW: Those will be less noticeable with IBOC?
Laird: Yes, hopefully none. Basically, it will have the dynamic range and interference similar to a CD.
Another effect is we as broadcasters have spent a lot of effort working with audio processing vendors to mask the problems of existing analog broadcasting. In other words, denser audio, trying to keep the music reasonable-sounding but to cover all the flaws that are in the broadcast system.
One of the big effects is the dulling effect of the FM pre-emphasis curve. As you process hard, the end result is either high-end distortion or blur or reduction. That is not an issue with digital. All of a sudden, you can have real bright, high-impact high end in the digital world. The analog processing artifacts will be gone. …
The preemphasis curve won’t be there. That can help in the overall sound.
On the other hand, we’re dealing with perceptual audio coders, and they have their own artifacts. We’re giving up a series of artifacts in the analog world, for a different set of artifacts in the digital world.
For example, if you listen to some of the Internet players now, you hear echoing. That’s an artifact in their digital coder.
RW: What are Journal’s technical goals for 2001?
Laird: We’re still working on getting our cluster infrastructure together. I’ve got a lot of studio projects, moving going on, within the company to get all our stations within a market into a clustered facility. That’s heavy on my plate this year and next year.
Within those moves and remodels, space-planning and all that, we’re upgrading technical facilities. Basically, most of our transmitter sites have been re-done, certainly all of what we consider to be the important stations.
RW: You mean upgraded?
Laird: Yes, antennas examined. Good transmitters, STL, exciter changes … and our focus now is the studio side. We have plans in place in most of our cities. We’re building new facilities in three of them. (Note: the markets are Boise, Knoxville and Wichita).
RW: Did you go with any one particular manufacturer on the transmitters?
Laird: No. In some cases, I was looking for the knowledge base that existed and commonality of maintenance parts.
For example in Boise, Idaho, we have a huge transmitter plant revision. We’re literally redoing four FM stations, three of them co-located on Deer Point. Most of the transmitters we own there are Continental. So it makes sense to me to match that so you can have the same tube in stock and same spare parts in essence.
Yet, we recently bought a Harris solid-state, a 7.5-kW in another market. In some of our other markets, we have exclusively Harris transmitters. In another market, we have a lot of BEs.
RW: How are you handling Journal’s digital storage and editing systems?
Laird: We had seven different systems in the company. We now have three: Scott Studio Systems, Computer Concepts and Dalet. …
Some (of this) was determined by how much engineering personnel we could have. If for instance, in an eight-station cluster where we have three full-time engineers, I can’t have a system that’s going to require a lot of maintenance.
RW: How many engineers do you have at each station?
Laird: It varies with the cluster. Our smallest engineering staffs are at our three station (clusters) where we have a chief engineer and we supplement with a contractor of some kind.
RW: And more at the larger stations?
Laird: Yes. For instance, three full-time broadcast engineers and a full-time IT person in Omaha, where we have eight stations.
RW: How do they buy equipment? Do they need to approve it through you?
Laird: We make capital plans. We do not do group negotiation. We don’t put a pile of stuff together and go to one vendor and ask for a deal. We plan each market individually. … I’ve been involved in the design and contract negotiation for a building remodel we’re doing in Witchita, (a) $1 million project. But when it comes down to a transmitter, the chief engineer does it.
RW: What are the most important technical decisions your group has to decide in the next five years?
Laird: How to transition to digital. If you’re looking at the five-year scope, how should our facilities be laid out to take advantage of the doors that digital is opening up? Right now there is no vendor that has a through-the-facility solution that makes financial sense for the medium-market group.
We’re seeing inklings like Klotz or Logitek. Or Computer Concepts Epicenter. You kind of see ideas of how an all-digital facility might look. To try to build one today for a medium market is very expensive. So the decisions we have to make right now is where we absolutely have to do something.
In most of our facilities, we’re doing hybrid-digital things: maybe a digital console that drops in using both the analog and digital outputs to feed different devices such as the hard-disk system, analog-in at this time, and perhaps digital, to a digital STL or digital processor.
What I mean by expensive is that to just gut a facility to go all-digital is difficult because of cost. So we’ve put together an evolution plan that will get us there over time.
RW: How did you get into radio?
Laird: Through college. My roommate was president of the college radio station that the student body had voted to build. This was AM carrier current in 1960 at a small college in Illinois, College of the Principia. I started off as a physics major, math minor.
RW: And then it was on to L.A.’s 50 kW KADY(AM)?
Laird: It was an RF snake pit. The antenna didn’t work . … You didn’t know if the transmitter would run for two minutes, two hours or two days without a massive explosion. They had been at the site for four years. They had operated at 10 kilowatts for over two years because of the failures at full power.
The first night, I’m listening to this thing and it sounded like feedback. …. I asked the transmitter supervisor for a roll of shielded wire, I got a roll of 8454 Belden and I went into the studio and disconnected the output of the audio console and hooked the wire up, ran it down the hall, into the transmitter room, and connected it directly into the input of the limiter. It was like magic.
So for three or four months, there was duct tape on a piece of wire about 150 feet long running from underneath the studio door, down the hall into the transmitter room as we rebuilt and redid the wiring of the radio station to get rid of RF.
