Cris Alexander, CPBE, AMD, DRB
Crawford Broadcasting Company
HD Radio Alerting
There are lots of good things going on in the HD Radio world these days, all of which couldn’t have come at a better time. Although HD Radio continues to make steady gains in the automotive sector, overall its growth had leveled out. Some stations have even turned their digital signals off for various reasons, many times because first-generation equipment has reached the end of its life and there is no budget for replacement or upgrade. That’s reportedly what happened with KOA here in Denver, which is really too bad. I miss hearing the news in HD quality on my way in every morning.
Announced the first week in September, DTS has acquired Ibiquity Digital for $172 million. This portends good things for HD Radio. DTS has announced plans to expand HD into a greater number of consumer devices and push for integration in mobile devices and home entertainment systems as well. And DTS very likely has the horsepower to push HD Radio past the point of “critical mass” in the automotive sector as well.
Unrelated to all that, stations all over the nation are implementing a technology that connects the HD Radio data stream to EAS. Once set up and working, alerts appear on the displays of current-generation HD Radio receivers. Even when off, such radios will “wake up” on receipt of an alert in much the way that many weather radios do when a weather warning is received.
We played “test pilot” at Crawford-Denver last month and found the implementation process to be straightforward and easy. In a nutshell, it required:
• Insuring that the exporter had the correct firmware version and upgrading if necessary
• Performing a firmware update on the Digital ENDEC EAS unit.
• Setting a few parameters, including the exporter IP address, in the ENDEC
• Setting a parameter in the exporter
Once that was done, a triangle appeared on the display of the HD Radio receiver we were using for testing. Subsequent tests appeared on the screen (there was no “wake-up” with the RWT and RMT but there should be in the event of an actual alert).
Now, Crawford is rolling out this technology across the entire company with good results. It doesn’t require a lot of effort and it’s something that is of great benefit to the public and something we can promote. With an HD Radio footprint of 2,300 stations covering 90% of the U.S. population and a claimed 35% penetration of the new car market, there are a lot of folks out there with HD Radios (whether they know it or not). As DTS takes over, those numbers are only going to go up.
For Want of a Part…
In mid-August we took a lightning hit in Albany, evidently on one of the array towers at the collocated 50 kW transmitter/studio site. The worst of the damage was fairly confined to main and aux transmitters plus a couple of relays in the phasor controller. The automation computers and server had to be restarted to get them behaving right again, and we have an unknown issue with the large UPS feeding the engineering/transmitter room, but those things did not keep the AM/FM combo off the air. It was the transmitter issues that were the real kick in the head.
Our very capable engineering crew in Albany jumped right on the problem but without a lot of initial success. After bypassing the failed interlock relays in the phasor controller, the main transmitter was lit up like a Christmas tree with warnings all over the place and would not run at more than a few hundred watts. The aux would come on and make RF power but would not modulate.
The decision was quickly made to focus on the aux, since the issue with it was likely low-level and easily remedied. That was undoubtedly the correct course of action but it was anything but a quick fix. Our engineers found seven different issues requiring a handful of parts from the spares kit to get it running again. The aux is only 5 kW instead of 50, but at least the station was back on. The FM, which has separate programming and transmits from a site northwest of the city, was not affected.
With the pressure (somewhat) off, our engineers were then able to focus on the main 50 kW transmitter. Expecting the worst, what they found wasn’t really all that bad. The main AC power contactor, which bypasses the step-start resistor when energized, was burned out and physically broken. The transmitter would run at very low power but not more than a few hundred watts at which point the voltage drop across the step-start resistor would reduce the PA voltage below the operational threshold and light up the status panel in red.
It seemed a simple matter, then, of calling the manufacturer and ordering a replacement contactor. The problem is that particular model of solid-state transmitter, installed in the mid-1990s, has been out of production for a few years now and the manufacturer no longer has stock on the AC power contactor. In fact, the manufacturer of the part itself no longer makes it, so the transmitter manufacturer had to scramble to source something that would work. They did, after several days, find something, but it has a 9-10 week lead time. So the 50 kW AM in Albany will have to operate at 5 kW on the aux for more than two more months until we get the part.
This is very frustrating, and it’s a situation that I have run into a number of times in recent years (although this is the first time I have encountered it with this particular manufacturer). I do understand that it probably doesn’t make a lot of fiscal sense for a transmitter (or any) manufacturer to keep stock on a $2,500 part that very seldom if ever fails, but I can’t see where a manufacturer can claim a device is “fully supported” if they don’t keep stock of – or at least keep tabs on where they can quickly lay hands on – such critical parts.
More and more these days, broadcast equipment manufacturers rely on other manufacturers for such items as power supplies and subassemblies. It reduces their costs to simply order up large quantities of switching supplies (or whatever) instead of tooling up and making them in-house. In going this route, however, they give up a certain level of quality control. They can use burn-in racks to test these devices and subassemblies before putting them in their equipment, but that only weeds out the worst of the lot. The president of well-known manufacturer of audio processing and telco/IP interface equipment told me a few years ago that vendor power supplies were his biggest support headache.
Even the top-tier of broadcast transmitter manufacturers is now farming out some of its major subassemblies. We only found this out when we took delivery of a 40 kW solid-state FM transmitter a few months ago to find that a number of items had broken their solder joints in shipment. That would never have happened in the day when this manufacturer made all its own boards.
The point of all this is that manufacturers are “outsourcing” more and more and those sources often dry up. If these manufacturers don’t either invest in a significant level of excess stock or take other measures to make sure that parts will be available when needed five, ten or even twenty years down the road, users like us are going to find ourselves in a situation just like I am in with the Albany transmitter.
If you have news to share with the Rocky Mountain radio engineering community, drop me an email at firstname.lastname@example.org.