KFMB-AM Restores 50 kW Nighttime Power

Making Waves – Commentary 

In case you missed it, the FCC last week dismissed KFMB-AM San Diego’s FCC application to decrease its nighttime power to 10 kW.

Say whaaaat?

KFMB-AM went from 5 kW to 50 kW nighttime power on 760 kHz in 1992 when state highway 52 was built between its towers and the station could leverage the Caltrans displacement funds to up its power. They tightened their peanut shaped antenna pattern with the third tower in order to continue to protect co-channel WJR Detroit. The lower daytime power is a rare case in the U.S. , but with KBRT Avalon short spaced at 740 kHz, KFMB wasn’t allowed to increase its daytime power past 5 kW. In most U.S. locations, stations either lower power at night or change to a directional pattern to protect the signals of stations that came before them.

About a year ago, the station (under my technical management at the time) decreased its nighttime power to a compromise 10 kW under a Special Temporary Authorization designed to experiment with the effects on expenses and income. What the experiment couldn’t determine was the future asset value of the station.

At the expiration of the STA, the station, under new technical management, filed a permanent application to keep the nighttime power at the STA’s 10 kW level. In late July, the station withdrew the application, stating the station would return to its licensed 50 kW value, and KFMB has since done so.

Why Reduce Power in the First Place?

It’s easy to say, “Just improve your programming with live and local and your ratings will bring in enough revenue.” How much money are you willing to throw at a medium no one is listening to? Even stations dominating their markets for decades, like KGO San Francisco, have regressed in recent years. It’s hard to sort out how much is the fault of management for getting rid of the talent people listened to when the station dominated versus how much the audience was leaving anyway. Some small stations report adequate income supporting local talent with live morning shows, but they are increasingly rare cases with very special management, low wage talent, and low costs of operation.

Faced with competition from better sounding FM, satellite, downloaded files, and streaming audio, AM’s audience has been cut down to a sliver of its 1960’s levels. Without an audience, sales staff can’t sell ads. Without ads, they can’t pay wages or the electric bill.

While I won’t discuss the inside details of the station’s decisions to try a lower power and then not do it, I can talk about the technical economics of AM broadcasting in general. Spoiler: they’re not good. Let’s list the arguments for and against lowering AM power permanently.

Cut Operating Costs with a Reduced Electric Bill

If operating cost reduction is the goal in reducing nighttime output power, the electric bill is a surprisingly poor way to do it. First, nighttime electrical power is much cheaper than daytime power. Second, solid state transmitters are much more efficient than that old tube-type beast you might have cut your teeth on. Third, we have available Modulation-Dependent Carrier Level (MDCL) techniques that further improve transmitter efficiency by 22% or more.

At KFMB-AM, the 25-year-old Harris DX-50 looks and operates pretty much like the day it was installed, thanks to excellent maintenance by Rick Bosscher, one of the best RF guys in the country. An MDCL kit is available for the MW, but at this point, you’d be stirring up the circuitry that has a few contact corrosion issues. And the ROI at this hardware age may not pencil out. You might argue that when the kit was available, it might have made more sense.

But We Don’t Want to Decrease Our Asset Value

I would argue that that ship sailed about twenty years ago. The owners of KCBQ just down the street sold out to Salem when the getting was good.

If you reduce the value of the nighttime signal by decreasing its “footprint” in the US west spectrum map, are you really decreasing the value of KFMB? Yes, an existing station in Denver or Arizona would be allowed to increase their signal in response, but remember that you aren’t serving coast-to-coast trucker radio–your audience is all tucked into San Diego County. You can’t argue that you would lose Los Angeles audience because there isn’t any–KBRT 740 pretty much wipes out anything north of the county line, day or night.

We Can Save Money on the Next Transmitter Purchase

True. Let’s say you spend $60,000 on a new 10 kW AM transmitter or $160,000 on a 50 kW transmitter. Let’s say they last twenty years this time. That’s $100,000 difference amortized over 20 years, or $417 per month, without considering the tax write-off and assuming you have the cash.

Not a factor, though it would make a hit on your cash flow that first year.

But We Need to Maintain a High Signal-to-Noise Ratio

True, AM is hurting in no small part because of the bazillions of switching power supplies radiating on-channel. Not a huge problem in cars, but at home—forget about it. Rick and I did some driving around and found the KFMB-AM signal was robust at 10 kW–remaining the largest signal in the county–but it did get hurt in that one parking lot in Romona….

It Doesn’t Matter–It’s About the Real Estate

For years, owners have been selling out the land out from under their AM transmitter sites. When I moved away to college in the mid-1970s, I worked at a Top 40 1 kW daytimer that fed talent to big stations all over the Pacific Northwest. The station was entertaining and a money-maker. A few months ago, the station brought their towers down, went silent for good, and sold the land they had been on for 58 years. Stations everywhere are either going silent and closing their doors or sharing towers and accepting low power nighttime non-directional patterns.

Let’s say your station was just treading water, but the ten acres it was sitting on was gaining value at about 8 – 10% per year. Whether or not you had hope in restoring the value of the broadcast property becomes immaterial. Even if you go silent and sell the property, the increase in valuation since the 1964 purchase makes it worthwhile, and you made a nice operating profit back before 2000.

That’s why I don’t entirely understand the value of the 50 kW nighttime signal at KFMB. Ratings were never affected by the reduction to 10 kW. You can listen at night and deduce that there’s absolutely no profit from playing ads past afternoon drive time. Any increase in power at night is a complete waste…unless you believe there is still value in the AM asset at that increased power.

So What About Digital?

In fact, there MAY be value in delivering an all-digital signal with a disciplined spectrum footprint (meaning KBRT and KFMB could co-exist) and high quality audio at 50 kW to Southern California and Nevada when it’s allowed in the future, and that’s a gamble that could be worth the increased operating and capital costs in the meantime. One of the things about people who make a lot of money over time–they can see farther in the future than most of us have the patience for.

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