All posts by Gary Stigall

Making Waves: DST Means Work for You and Me

On March 11, 2007, Daylight Savings Time starts earlier than last year. Congress moved the date with a simple vote. Now you and I have to do all the dirty work to make our computerized world fall into place. Are you ready?

When I was 15 and enthused about ham radio, I bought from Allied Radio one of those 24-hour wall clocks and set it for Greenwich Mean Time. Yeah, I was that geeky. What that clock showed me is that all the fuss about time zones and daylight saving time is completely unnecessary. Why couldn’t the whole world run off one time and change their local school and work times to whatever they wanted? Does it really matter if they’re going to work at 0800 in London and we’re going to work at 1800 in San Diego? Instead, governments and corporations spend enormous resources tracking zone boundaries and daylight saving periods. DST serves only as a way to change the numbers on the clock, and is more meaningless the closer you get to the equator where sunrise and sunset times don’t change much. If safety and conservation are important at the upper latitudes, why don’t we just change the starting times of the school or work day to suit the daylight available?

In 1973, they messed with daylight saving time briefly because oil supplies were squeezed. They wanted more daylight in the afternoon so that we didn’t run so many lights at work. But what I remember is that we were suddenly getting up in utter dark, running the heat and lights at home an hour earlier than before. The problem was that at the 45th parallel, there was only so much daylight. At the time I worked at a small daytime only Class IV AM station in Oregon, and during December and January I would sometimes work weekends from the 8:30 AM sign-on to the 5:30 PM sign-off. According to Wikipedia, studies of the effects of DST have variously concluded savings of energy and traffic deaths as well as loss of savings to economic efficiency and increased energy peak loads at sunrise.

On March 11 this year, we’re changing from the usual early April changeover to DST to March 11. The United States change is part of the Energy Policy Act of 2005. Again the justification is to synchronize the workday to the hours of daylight available so that we are less dependent on Middle East oil.

The international ramifications are interesting. Canada decided to adopt the U.S. plan to move DST; Mexico did not. For the first time that I can remember, Tijuana will be in a different time zone from San Diego from March 11 until April 1. My station, XETV Fox 6, will be in the uncomfortable position of advertising programming times to its majority U.S. audience in Pacific Daylight Time, while the country of license observes Pacific Standard Time.

You may have work to do in preparation for March 11 this year. If you run Windows XP or Vista on the internet, you should be able to download their normal maintenance update to change the automatic DST switch date. If you run a machine isolated from the net, you’ll have to schedule a download or just change the time zone of the workstation in question.

It turns out that the Dallas Semiconductor real time clock (RTC) chips that control time in many computers have hard-coded DST changeover dates so that can’t be overcome except by manually changing the time or GMT offset.

You can program Macintosh computers to change automatically on the correct dates by editing the /etc/localtime file. Instructions can be found here. Linux.com has a clock howto with DST information.

If you depend on Java runtime applications, see Sun’s DST FAQ. It appears that if you accept the Java RT update being pushed to your workstations this month, you should be okay.

You’d do well to look around for time-dependent systems that may need your intervention. Some vendors are offering software upgrades to automate the GMT offset at the new time. Triveni, for example, is asking $500 to upgrade its PSIP management software that includes revised DST changeover dates. If you have a collection of similarly needy boxes around your broadcast facility and you can’t get away with simply changing the GMT offset yourself, this time change is going to cost you.

FCC Busts Oceanside Church

According to the FCC citation, the San Diego office received a complaint of a signal on 1610 kHz in Oceanside. On November 2 last year, investigating agent Bill Zears found on Canyon Drive a Part 15 compliant 3 meter long antenna, but a 30 meter ground system. The FCC named Iglesia de Dios Ebenezer ("Ebenezer Church of God") as subject of the citation.

San Diego HD-Radio Progress Report

Digital radio broadcasting seems to be catching on in San Diego despite the high cost of installation and low listenership. Ibiquity Digital Corporation, sole provider of the FCC-approved IBOC system, built into its growth plan heavy financial incentives, including lower or no license fees for early adopters. Large groups like Clear Channel endorsed the move to IBOC, too.

Ibiquity is working the backend, too. We’re beginning to see and hear commercials boosting HD Radio and mentions of commercial-free subchannels. And radios with digital capability are showing up at Radio Shack, Best Buy, and Fry’s.

So what’s going on in San Diego radio?

Here’s a table of San Diego HD-Radio stations, courtesy of Ibiquity:

89.5 KPBS-HD1 FM News/Talk/Info San Diego State University
89.5-2 KPBS-HD2 FM Groove Salad from NPR San Diego State University
93.3 KHTS-HD1 FM Top 40 Clear Channel Radio
93.3-2 KHTS-HD2 FM Mega Spanish Clear Channel Radio
94.1 KMYI-HD1 FM Hot AC Clear Channel Radio
94.1-2 KMYI-HD2 FM Variety Clear Channel Radio
95.7 KUSS-HD1 FM Country Clear Channel Radio
95.7-2 KUSS-HD2 FM New Country Clear Channel Radio
97.3 KSON-HD1 FM Country Lincoln Financial Media
101.5 KGB-HD1 FM Classic Rock Clear Channel Radio
101.5-2 KGB-HD2 FM All Dave, Shelly & Chainsaw Clear Channel Radio
105.3 KIOZ-HD1 FM Rock Clear Channel Radio
105.3-2 KIOZ-HD2 FM Rock Clear Channel Radio
107.1 KSSD-HD1 FM Spanish/CHR Entravision
600 KOGO-HD AM News/Talk Clear Channel Radio

I asked three San Diego engineering managers about their HD-Radio projects:

Leon Messenie, KPBS

When did you first hit air?

July 29, 2005

What is on your subchannel?

Groove Salad – KPBS’s secondary digital channel. Groove Salad, a 24-hour music station, is a partnership between National Public Radio and Soma FM; and the result is, well, “groovy.” (From our WEB site, not my wording)

Any notable project stories?

The one thing that sticks in my minds was the first morning we were digital. The newscast came up to the point where we cue the traffic report and there was nothing but silence…dead air…. It seems that none of us Engineering or Programming types thought about the newly induced digital delay in the analog signal. This is done to align the analog and digital program streams for a seamless switch between them. This delay is about 8 seconds.

So here is what happened: The Traffic service listens to KPBS-FM off air. When they heard their cue it was already 8 seconds past the real point when they should have started talking. This confused them so much they just stopped talking for the entire report. The Engineering cell phones lit up like a Christmas tree. Needless to say emergency orders for dedicated mix minus phone lines between KPBS and the Traffic office were installed. I am just glad the Traffic service did not have a helicopter….

Recommended receivers?

Not that I recommend them but we use the Boston Receptor HD desktop receiver. They work pretty well with an outside antenna.

Are you considering a closed service for your reading service?

In May 2006 KPBS-FM was part of a test with NPR to test what is being called the extended digital service. We put the KPBS Radio Reading service into this area and then compared the sound quality and reception to that of the analog Sub Carrier receiver. This test was presented at the IAAIS conference at a hotel in Mission Valley. The Mission or as we in radio call it Missing Valley hotel was the perfect place to test this. In a room with about 150 people we listened to first the analog SCA receiver. The sound quality was terrible and you could barely hear the KPBS Radio Reading Service. When we switched the room audio over to the audio from the digital feed the room of people just gasped. The sound was perfect. It was very cool to be a part of something that was such a success. Work is being done now to make this a closed system in order to broadcast Radio Reading Services around the country without violating copyright laws.

John Rigg, Clear Channel Radio

When did you first hit air?

The Clear Channel San Diego stations were on in May of 2006, with the exception of KGB and KOGO which were on in early 2005.

Any notable obstacles?

No two installations were the same, even though the application for HD is software written by Ibiquity, manufacturers integrate differently and apply their own GUI to the exporters and importers.

Any warnings?

Planning, Planning, Planning.  If someone has already done this in your group, ask lots of questions, no need to re-invent the wheel.

Recommended receivers?

I have a JVC KDR1 in the car. It’s a great radio, no RDS on the analog though. I’ve heard great things about the Sangean Component Tuner although I’ve not personally seen one.

Is your group adding more HD-Radio stations?

Clear Channel is currently adding stations to the digital offering. I’m not sure of the schedule, but hey, Tucson just did an install.

Eric Schecter, Lincoln Financial Media

 

What stations have HD-Radio broadcasting? What format?

KSON-FM has country on HD-1. We don’t have an HD-2 yet

When did you first hit air?

December 22, 2006, just in time for Christmas.

Any notable obstacles, funny stories, warnings?

Yes, several. The obstacle that was eventually overcome was getting the data to the Harris Flexstar Exciter from the studio where the Exporter (fancy name for a Linux box with soundcards) lives. We use 7 of 24 time slots in a T-1 Intraplex  multiplexer to accomplish this. It appears that the the module adaptors that present a 10 Base T interface only operate at half duplex. In the end, we used a hub rather than a switch at the studio end, and everything seems happy.

In the warning department, first some background: Our transmitter is a Harris HTHD+ and it utilizes a 4CX20000C tube biased AB1 (sort of) to make 18kw transmitter power output (TPO). The FM+HD signal combining occurs in the Flexstar Exciter. This is known as low-level combining. In order for the transmitter system to make spectral compliance, the exciter uses RTAC, or Real Time Adaptive Correction. While you can get away with some VSWR on a regular transmitter, a hybrid digital system really needs to have a flat transmission system (antenna, feedline, fittings, switches) to achieve optimal performance. We have work to do to optimize a system that is about 25 years old.

Recommended receivers?

I’ve evaluated the Boston Acoustics Receptor. With a good antenna, it’s a good performer. With a short piece of wire close to the radio, the display electronics tend to de-sense the receiver, and it’s as deaf as rocks. BA is now supplying folded dipole antennas based on NPR Labs tests. It receives both AM and FM. There are some good hidden menus for the experimenter in all of us.The price point for this fine sounding radio is $299.

I’ve also evaluated a professional tuner by ADA. It’s actually two tuners in one chassis, and is made for tech centers in the stations. It will do both AM and FM HD, displays RDS and HD PAD data, and is a finer performer. Price tag is about $3500.

Do you plan to outfit your other stations?

Yes, KIFM and KBZT.

Mike Prasser, CBS Radio

Which of your stations have HD Radio?

Currently neither of my stations in San Diego are broadcasting HD. We are looking at second quarter of this year for both. The HD2 formats have not been finalized.

Recommended receivers?

Most of the receivers on the market are good. The most exciting thing that I saw at CES last week was a company called Sideport. They have created a single HD chip that contains all of the components needed for HD with a much lower current draw for $20. Currently there are two chips needed one at $15 and one at $20. So this make HD Radio smaller and cheaper to make.

Making Waves Commentary: The Shotgun Approach

A little over two years ago, Fox 6 photojournalists were showing up at our service shop with odd, seemingly unrelated problems with their camcorders. The symptoms involved anything from servos to color encoding to erratic controls. We learned that the solutions, however, were almost always the same–change out a group of surface-mounted electrolytic capacitors or replace the entire circuit board. The DVCPRO camera or studio deck always went away working again until another, unrelated, failure occurred. Repair veterans like Greg Capalbo of GRC Electronics were warning us that the failed capacitor scenario was an epidemic, especially with Panasonic gear, but also to a lesser extent with Sony and other brands. And Panasonic was not supporting out-of-warranty fixes with either parts or labor.

As we saw more electronics come in with bad capacitors, it became increasingly clear that the future duties of our ENG specialist Ladd Prier might involve an endless, daunting series of tracing erratic component behavior to a circuit, then buying new caps, awaiting their arrival, then swapping them out and hoping the bad behavior would disappear. We visualized the coming stack of broken equipment and unhappy users. There had to be a better way.

Ladd and I come from a time when a technician took pride in tracing an obvious equipment failure to one or more components directly responsible. When an RCA TR-3 2″ videotape player headwheel wouldn’t spin up, I would get the four-inch thick manual, an extender, and Tektronix 545 oscilloscope and through a series of calculated guesses, eventually find the open or shorted germanium transistor or diode, then replace it and check a couple of waveforms before pronouncing the monster ready for duty.

Fast forward 25 years. Today’s equipment contains little undocumented black boxes. When the servo fails, you change out the servo board. But what if all boards fail on all news equipment? We were looking at a potential of essentially having to replace part-by-part all of our five-year-old Panasonic equipment.

A Better Way

On a whim, I called our temporary agency, TLC Staffing, and asked if they had any registered rework specialists. In manufacturing, these are the people who take circuit boards with errors on them, either by design or by manufacturing defect, and change out components as ordered to resurrect those boards. {mosimage}They are skilled at performing Lilliputian surface-mount technology soldering, and with incredibly tedious repetition.

TLC sent us Vu Le, who appeared businesslike, cheerful, and ready for action. Over the next ten weeks, he replaced nearly every surface-mounted capacitor in every Panasonic DVCPRO deck, both from the field and from inside the plant. He changed up to 400 caps a day for a total of nearly 20,000. Total cost: nearly $16,000 including parts. Every VTR and camcorder finished worked like new, especially when heads were changed at the same time. There were no more mysterious misbehaviors, a fraction of the downtime, and Ladd was now free to take care of the more normal maladies of ENG.

Months after Vu went on to other work, we noticed more equipment failures that seemed as though they could be capacitor related. Modules in our Wheatstone TV-80 mixer started having problems with bandpass and open circuits. Our digital Hitachi studio cameras had assorted color problems.

This time we didn’t hesitate. We hired temp Daniel Yanez to swap out all the electrolytics in those devices, though less careful to estimate the extent of the project. Now some 10 weeks later, Daniel is still slaving away, module after module. He began filling a three-gallon plastic jar with the tiny devices, and now it’s nearly a third full.

Obviously, if we knew the more about the exact nature of the failures, we could be more selective about the replacement. Were some of the caps higher grade? Which values really fail? If temperature is a factor, couldn’t we perform an IR scan to find the hotspots? Since we didn’t have a good composite history of the mixer and cameras across their user base, we didn’t have the knowledge to pick and choose what devices to replace, so we replaced them all. The basis for doing so was 100% empirical and 0% scientific.

Epilogue

Industry experts continue studying the science behind the SMT chip capacitor failures. It surprises me to learn that they blame not just chip chemistry, but physical conditions during manufacturing and board assembly. It appears as though bad things are happening to good companies with respect to their products not living as long as expected.

We bought replacement capacitors that were labeled as having a long expected life, but there’s no assurance that we’ll even double their life. In fact, we’ve replaced the camcorders in a surprise blast of capital funding. I expect the 7-year-old standard definition cameras and analog audio mixer can’t be far behind.

Daniel is looking for his next gig. Got bad stuff?


Comments

Courtesy CGC Communicator

The capacitor saga dates back to about 1998 and the wide use of surface mounted electrolytics. Those parts have a time and temperature rating. The ones supplied in most gear do not have the most generous ratings. While we deal with Sony, Panasonic, JVC, etc., their original board assembly may all be
done at one outside vendor. Thus, plenty of gear was built with marginal capacitors.  I first ran into this with Panasonic DVC-Pro recorders.  One audio card that was troublesome had 50 of the beasts on it.

The best way to test for bad capacitors is with a Capacitor Wizard that uses a high frequency to measure reactance. It works fine testing caps with no need to unsolder.

Roy Trumbull, roy547 (at) msn.com

 


 

The Panasonic DVC-Pros are the first and worst detected.

We tried Panasonic replacement kits and they didn’t fix all symptoms. I decided not to test the capacitors, figuring that we would have too many iterations of failure/remove/disassemble/test/replace/reassemble/return. Our rework guy could replace 400 caps per day, so I just said to heck with testing –replace them all!

It’s been my experience that measuring in-circuit reveals the problems in only one point in time and doesn’t address future cap failures. In our case, we haven’t had any symptoms in our DVCPRO decks since the mass replacement of capacitors.

Gary Stigall


URLs FOR ELECTROLYTIC PROBLEMS

Scroll down to the Great Capacitor Scare:
http://catless.ncl.ac.uk/Risks/22.73.html#subj9

This article discusses acidic leakage damaging circuit boards in mobile radios:
http://www.repeater-builder.com/motorola/spectra/spectra-caps.html

While this article is oriented towards PC board mounted caps, the cause is the same – bad electrolyte:
http://en.wikipedia.org/wiki/Capacitor_plague

And more links yet:
http://www.ttiinc.com/object/ME_Zogbi_20050919.html
http://www.badcaps.net/
http://www.theinquirer.net/default.aspx?article=24596 (re Dell)

All in all, it looks like bad electrolyte is the root cause.
In some cases it causes a reduction in capacitance value (which
changes circuit performance), in others it blows the tops off the
caps, in others the electrolyte eats its way out of the cap and
eats up the board.

Mike Morris, WA6ILQ

KSDS Gets FCC OK to Raise Power

(Disclosure: The author is employed by Bay City Television, San Diego-based programming, advertising, and marketing arm of XETV Tijuana)

The FCC issued on October 31 a construction permit for KSDS (FM), 88.3 MHz, to increase power from their current 3 kW vertical to 22 kW ERP vertical, upgrading the facility from class A to class B1. The station, operated from the campus of City College downtown, but transmitting from a tower at Mesa College in Linda Vista, has been operating since 2002 with 3 kW ERP vertical polarization after a compromise worked out with Fox Television affiliate XETV, channel 6 in Tijuana.

The latest CP approval comes as a surprise to XETV, which has fought the increase in power since 1995 on grounds that it creates a substantial interference zone since the stations are only separated by a minimum of 200 kHz between allotments, or 550 kHz between carrier centers. The stations represent a unique situation in the U.S., where a border non-commercial FM had protected a channel 6 TV signal broadcasting in English-language from Mexico. The new construction permit appears to change the crossborder relationship by declaring previous protections null and void.

The new FCC ruling says that previous international broadcast treaties do not specifically deal with the TV-FM interference issue, so the XETV signal has no rights to protection from U.S. non-commerical FM stations after all. At the same time, the order gave recognition to XETV public service efforts and ordered that KSDS broadcast its increased power in vertical polarization only. KSDS must provide a shallow null to the southeast, and they must remediate any known interference and report unsolved cases to local FCC inspectors.

KSDS intends to have its facilities ready for increased power by spring 2007.