Random Radio Thoughts

Cris Alexander, CPBE, AMD, DRB

Crawford Broadcasting Company

 It’s Been Awhile…

 Indeed it has been awhile since I have written anything for these pages. It wasn’t for lack of something to say; rather, it was because I was busy, doing the Fred Baumgartner trick of commuting to the west coast just about every week for the past months.

What was I doing out there, you ask? I was building a new 50 kW four-tower directional array in Orange County, California. Our L.A. area station, KBRT, has broadcast from Catalina Island since 1953, but its lease is up the end of 2013. So for several years (since mid-2007) I have been hunting for a suitable site, developing the site and building out the new facility.

The new site is located in a basin at the top of Black Star Canyon in the Santa Ana Mountains. Why on earth would anyone build an AM site on a mountaintop? Because in Southern California, the BANANA rule applies: Build Absolutely Nothing Anywhere Near Anything.

The new site has reasonable conductivity along paths into most all of the listening area, especially Orange County and Los Angeles. And it has a line-of-sight to our studio near John Wayne Airport in Costa Mesa. We were able to make an 11 GHz path with one hop from the studio roof.

The facility features a Nautel NX50 main transmitter (the old main, a Nautel XL12, will be coming over from the island to serve as the aux at the new site), Kintronics provided the phasing and coupling system and Magnum provided the four 281-foot towers. I used a ThermoBond 12 x 30 prefabricated transmitter building (it was FUN getting it up five miles of narrow switchback dirt road to the site!).

We put a 13 foot high foot-thick concrete block wall around the transmitter building, generator and each tower base to keep yahoos from shooting up anything important. The site is on private land that we own but is surrounded by the Cleveland National Forest. Some folks don’t see the distinction between “public” and “private” land.

I used moment-method modeling to determine the operating parameters, and Amanda Hopp and I tuned the array up in less than two days. It went on the air February 28. Jim Schoedler has asked me to do a presentation on this project at one of our chapter meetings this spring. If you just can’t wait, there are photos and a full narrative of the project in the gallery at: www.crawfordbroadcasting.com/oakflat_gallery/.


It was hard not to chuckle a little bit at the news of the EAS hack that produced an on-air warning of a zombie attack. That episode was a lot like the roadside message board hacks that have been in the news in recent months warning of the same thing.

But there is a more serious aspect of the EAS hack, and that is if someone can hack their way in and produce a somewhat humorous warning that is obviously false, couldn’t someone also hack their way in and produce an activation that is not a bit funny and not so obviously false? That kind of thing could produce a panic at worst and kill off what little credibility the EAS system has at best. Clearly we as an industry have to do more to protect our EAS infrastructure.

In our company, we have our EAS units behind a solid firewall, and the passwords are all changed from the factory defaults. There is no port-forwarding that would expose these units to a direct connection from the outside world. Those are the kinds of measures that everyone should have taken when installing their CAP-enabled EAS equipment, but my guess is that many simply plugged their units into the station router and left the passwords at the defaults. With that kind of “security,” it’s no great stretch to figure out how someone in the know could hack their way in.

If you haven’t taken at least some security measures to protect your EAS equipment, you’d better do that now. It doesn’t take a lot to remove it from the “low-hanging fruit” category.

Copper Theft

It seemed like copper theft sort of waned there for a year or two, but it’s coming back in a big way. Since the first of the year, I have had two air conditioner condenser coils stolen and the condenser units destroyed at one site, and at another site we had 90 feet of transverse copper strap stolen from the center of the antenna field.

In the former case, after the first theft we moved the unit to the roof of the building and put a fence around it. A lot of good that did. In the other case, we blacktopped over the ground screens from the tower base out to a 24 foot radius. That along with the cameras, alarms, sirens and strobes at each tower base stopped the theft for a good while, but now the thieves have moved to the center of the antenna field where we have no camera coverage, alarms or blacktop.

At the new site in California, I had some custom steel cages built to protect the emergency intake/exhaust hoods on the transmitter building. These bolt all the way through, making the adjacent wall more vulnerable than the hoods. We are now having something similar made for the condenser unit in St. Louis. We’ll tie it into the alarm system so that if it is opened or disturbed it will trigger the burglar alarm. I would rather send the copper thieves elsewhere than have them destroy another unit, even if we did catch them in the process.


There are some pretty good and sophisticated long-range microwave Doppler motion detectors on the market these days, and we’ve installed an array of them at our new site in California. If anything bigger than a coyote moves through the antenna field, it trips the alarm. The monitoring center then pulls up the camera array and determines whether the alarm is real or not. If it’s real, our armed security contractor is called to respond (they also make random patrols of the site). We are considering taking some of these measures at sites where we are having issues away from the transmitter building and tower bases.

Times are tough, people are desperate and copper prices are up. All of this means that copper thieves are on the prowl and broadcast engineers have got to take extraordinary measures to protect their facilities.


A few reminders for us radio engineers…

AM annual occupied bandwidth measurements are due every 14 months. Are yours up to date? Better make sure of that.

Arrays licensed under the moment-method rules must recertify their sample systems every other year. The folks at the Media Bureau tell us that this is keyed off the license grant date, not the date the original measurements were made. Are your recert measurements current?

This is the last month of the first quarter, so if you haven’t made your quarterly inspection of “…all automatic or mechanical control devices, indicators, and alarm systems associated with the antenna structure lighting to insure that such apparatus is functioning properly,” you have this month to get it done.


If you have news to share with the Rocky Mountain radio engineering community, drop me an email at crisa@crawfordbroadcasting.com.