Text and photos by SCOTT FYBUSH

In most markets, the biggest AM station in town is the one that traces its history back to the dawn of radio in the 1920s. But San Diego is a late bloomer in many ways – and so is one of its heritage AMs.

KFMB's building
KFMB’s building

The KFMB radio hallway
The KFMB radio hallway

On this April day in 2012, our visit was to KFMB (760), which today is one of the two big talk voices in San Diego, running 50,000 watts at night and (for reasons we’ll get to shortly) 5,000 watts before dark. But when KFMB started in 1941 as the third station in town, it was just 250 watts on a class IV local frequency: its construction permit originally read “1420 kc,” but by the time the station made it to the air from a rooftop tower atop the Spreckels Building on Broadway downtown, the NARBA shift had moved KFMB to 1450 on the dial.

KFMB's AM control room
KFMB’s AM control room

KFMB's talk studio
KFMB’s talk studio

We’ll pick up KFMB’s technical history again as we get out to the transmitter; its studio history found the station at several locations in or near downtown San Diego for its first four decades on the air, most prominently at the corner of Fifth and Ash, which is where it was joined by KFMB-TV (Channel 8) in 1949 and later KFMB-FM (100.7). KFMB’s ownership shifted several times over the years, including a stint in the hands of “Lassie” producer Jack Wrather, who also owned Muzak for a while. In 1964, the KFMB stations were sold to Illinois-based Midwest Television, which owns them to this day.

KFMB's bullpen area
KFMB’s bullpen area

KFMB radio rack room
KFMB radio rack room

In 1977, KFMB left downtown behind for Kearny Mesa, north of downtown in a triangle bounded by the 805, 163 and 52 freeways, and it’s been there at 7677 Engineer Road ever since. This one-story building is divided into separate sides for radio and TV, and since we’re with the radio engineering crew this day, we turn right at the lobby to go see their side of things.

KFMB-FM production room
KFMB-FM production room

Looking into the KFMB-FM studio
Looking into the KFMB-FM studio

The KFMB radio studios are largely arrayed along one hallway that runs parallel to the front of the building. KFMB(AM) gets the inside of the hallway, with a control room that looks into a fairly spacious talk studio, which in turn looks into a news/traffic booth that opens into what I think was once a newsroom area. Today, it’s a sort of open bullpen that’s used primarily for video and photo shoots featuring KFMB talent and visiting guests.

A new KFMB-FM board
A new KFMB-FM board

Cool mic boom
Cool mic boom

Across the hallway, a row of studios along the outside of the building is home to KFMB-FM (100.7). It’s a “Jack FM” adult hits station for most of the day, but unlike most “Jack” stations, this one has a high-energy morning show featuring longtime San Diego hosts Dave, Shelly and Chainsaw. Making all that radio happen requires several studios, including one dedicated to the morning show. When we visited, the engineering crew was in the midst of replacing some of the older PR&E boards (this was Pacific Recorders’ hometown, after all) with newer Harris boards. And check out the nifty way all those talent mics hang spider-like from the ceiling, leaving a nice open table surface underneath and no danger that anyone banging on the furniture will make noise on the air.

KFMB's north and center towers
KFMB’s north and center towers

KFMB's south tower and transmitter building
KFMB’s south tower and transmitter

KFMB's phasor
KFMB’s phasor

Transmitters? Yes indeed – but the current version of the AM 760 transmitter site needs some historic background before we head inside.

KFMB wanted very badly to get off its initial home at 1450 on the dial. Within just a few years after signing on, it applied for 1170 (but lost that channel to newcomer KCBQ), then tried to buy out KPRO to the north in Riverside so it could move to KPRO’s frequency, 1440. By 1948, KFMB had found another option: it slid all the way down to the bottom of the dial, 550, taking up residence in 1948 on its new channel from a new site in the Grantville neighborhood on the east side of San Diego.

KFMB's main DX50
KFMB’s main DX50

KFMB's racks and Power Rock
KFMB’s racks and Power Rock

Even with a nice 5000-watt DA-N signal, KFMB didn’t spend very long on 550. In 1954, it was on the move again, sliding one notch down to the 540 frequency that was newly opened to broadcasters. It was a nice clear channel, but it was also a frequency that Mexico insisted was properly its own under international treaty, and so KFMB was once again forced to seek a new home. The station hoped to go to 830, but that clear channel’s legacy occupant, WCCO in Minneapolis, objected, and so after much Washington legal work KFMB was assigned to 760 over the protests of that clear channel’s legacy occupant, Detroit’s WJR, as well as objections from daytimer KBIG (740) on Catalina Island, off the coast to the north. (In the end, of course, WCCO’s clear channel would be broken down anyway, used up in Orange County by what’s now KLAA.)

By the time the frequency change to 760 happened at the end of 1965, KFMB had already begun migrating from its Grantville transmitter site to a new two-tower facility about three miles to the northeast on the western edge of Santee.

KFMB's transmitter building
KFMB’s xmtr building and freeway embankment

Center tower base
Center tower base

It’s that facility where we find KFMB today, but it looks nothing like it did in 1965. Along the way, KFMB was able to make one more signal upgrade: because KBIG (now KBRT) signs off at sunset, KFMB was one of the first American AM stations to be allowed to run more power at night than it can use during the day. At sunset, KFMB actually powers up from its daytime 5 kW to a full 50,000 watts.

And that led to the most recent big change here: this site was completely rebuilt in 1991, including a new spacious transmitter building that also provides off-site storage for KFMB-TV’s remote trucks. The existing KFMB towers were taken down and replaced with three new ones. But to make that new three-tower array fit, a most remarkable thing happened here: the third tower had to go on the north side of the 52 Freeway that runs right on the north edge of this site. So CalTrans built a massive culvert under the freeway, starting up on the side of the embankment where the center tower sits – and if you’re driving from Kearny Mesa to Santee, you’ll pass right through the KFMB array on the way!

Inside the building here, Rick Bosscher and his crew keep up a facility that’s absolutely spotless. There’s just one 50 kW transmitter in here, a Harris DX50 backed up by a Continental Power Rock as a lower-powered aux. And yes, there’s even AM stereo gear here, albeit no longer in operation. It’s as clean a transmitter room as you’ll find anywhere, and a very stable home for a station that’s had a long trip to get here.

Thanks to KFMB’s Rick Bosscher and Scottie Rice for the tours!

2014calendarThe 2014 Tower Site Calendar has been years in the making.

But the wait is over. The Tower Site Calendar, 2014 edition, is still shipping daily and ready for immediate hanging on your wall.

Need a calendar or two? Place your order today and we’ll send them right off to their loving homes, spiral bound, shrink wrapped and best of all, with a convenient hole for hanging!

This year’s gorgeous electronic pinups include the iconic towers of Catalina Island, a combiner system in St. Louis, the twin towers of KNRS in Salt Lake City, a historic rooftop site in Jamestown, New York and many more!

Click here to order your new calendar!

Then check out our store page for our other great merchandise, including the last-ever FM Atlas, the new NRC AM Log and a model of the KSAN tower.

And don’t miss a big batch of San Diego IDs next Wednesday, over at our sister site, TopHour.com!

Next week: More San Diego, 2012