Wednesday, September 22, 2010

Hello Everybody! The Dawn Of American Radio

It's that time of year once again when I'm getting ready to head cross country from New York to Arizona for the winter. One of the things I do is stockpile a bunch of books to read through the season. At the top of the radio reading list this year is a book entitled "Hello Everybody! The Dawn of American Radio", by Anthony Rudel. It is the story of the diverse entrepreneurial pioneers of radio, covering the era from 1912 through the 1920s and 1930s. Touching lightly on the technical aspects and inventors of radio, Rudel emphasizes the entrepreneurs and evangelists, hucksters and opportunists who saw the medium's true potential.

From Rudel's website:

"Long before the internet, another young technology was transformed--with help from a colorful collection of eccentrics and visionaries--into a mass medium with the power to connect millions of people.

When amateur enthusiasts began sending fuzzy signals from their garages and rooftops, radio broadcasting was born. Sensing the medium's potential, snake-oil salesmen and preachers took to the air, at once setting early standards for radio programming and making bedlam of the airwaves. Into the chaos stepped a young secretary of commerce, Herbert Hoover, whose passion for organization guided the technology's growth. When a charismatic bandleader named Rudy Vallee created the first on-air variety show and America elected its first true radio president, Franklin Delano Roosevelt, radio had arrived.

With clarity, humor, and an eye for outsized characters forgotten by polite history, Anthony Rudel tells the story of the boisterous years when radio took its place in the nation's living room and forever changed American politics, journalism, and entertainment."

It arrived yesterday and it promises to be a great read. Available from and other booksellers. Published in 2008.

Saturday, September 18, 2010

Signal Patterns

Stephen from San Diego, CA, a reader of Mediumwave Oddities - Transmitter Power, wrote in with the following question:

"What stations actually are authorized with a HIGHER power at night than they are allowed in the daytime? I'll mention one - 760 KFMB San Diego, CA, about 7 miles from me. In the daytime they're only allowed a paltry 5KW omnidirectional, but at night they step up to 50KW."

An interesting question. And you mentioned signal patterns, all-important in the differences between daytime and nighttime mediumwave coverage.

I tweaked my database program Radio Data MW and came up with the following results:

73 US stations run higher power at night than during the day.

KFMB-760, your San Diego station, is the only one which runs 50KW at night and has a lower daytime power. KFMB uses one omnidirectional tower for daytime broadcasting. Power is set at 5KW during daytime broadcasting hours and 50KW at night. KFMB uses three towers at night to get that big 50KW signal out. But the pattern this time is pointed right out into the Pacific Ocean, to the southwest. San Diego's KFMB cardioid pattern has a deep, broad null at 60 degrees, nicely positioned for protection of Detroit Michigan's WJR-760 (50KW) and its western coverage area. Equally important, big gun KKZN-760, Thornton, CO (also 50KW), near Denver at 49 degrees is also protected, as well as a host of smaller US and Mexican stations.

KBRT-740 "K-Brite", a 10KW station in Avalon, on Santa Catalina Island is only a mere 85 miles to the northwest of San Diego's KFMB. It has a three tower array in use both day and night, pointing its signal due east to cover the Los Angeles and Long Beach areas, a scant 26 miles away. KBRT drops its power to a gasping 113 watts at night. Being nearly "co-channel" with KFMB at only 20 KHz removed, inspecting KFMB's pattern plot reveals that that the broad cardoid lobe to the northwest pumps an astonishing effective radiated power of 95KW up a 294 degree vector right at KBRT on Catalina. With a salt water path the whole way, that should be a lot of signal.

The next station with a big signal at night and a smaller one during the day is WLIB-1190 running 10KW daytime and 30KW nighttime, in New York, NY. WLIB uses three towers for daytime broadcasting and four towers at night. Both patterns are generally towards the east, with the nighttime pattern more focused and skewed a little more to the southeast. During the day it competes with WBIS-1190, Annapolis, MD (10KW), and WSDE-1190, Cobleskill, NY (1KW). WLIB's daytime pattern exactly bisects these two challengers on a line right out into the Atlantic Ocean. At night, WLIB only has to contend with New Yorker WSDE, as the Annapolis station is off the air.

The station with the greatest power differential, day to night, is WLAN-1390, Lancaster, PA. They run a mere 18 watts daytime and 1100 watts nighttime, both to a single, omnidirectional tower. Their nighttime power is a remarkable 61.1 times more than their daytime power!

WLAN's main competitor is WZHF-1390 (5KW), in Arlington, VA, a mere 92 miles away to the south-southwest. How does an 1100 watt station co-exist with a 5KW station at night when they are only 92 miles apart? Examining the tower pattern plots, you will find that WLAN in Lancaster, PA is exactly in a deep notch of WZHF's nighttime pattern.

Shown are nighttime pattern plots for San Diego's KFMB-760 and Avalon's KBRT-740, generated by Radio Data MW.

Tuesday, September 14, 2010

Winter DX Season 2010

Great mediumwave conditions were apparent three mornings ago (September 11). I'm an early riser, and at 6AM I'm usually on the way to the coffee shop DXing on the truck radio. Of course at that time of the morning it's still very dark out. The sun doesn't rise here until 6:40L. Tuning to 850 KHz at the top of the hour news, I caught a nice full ID from 50KW KOA-850, Denver, CO (1420 miles) at 0605L. The KOA radiator, a single tower located 30 miles to the southeast in Parker, CO, is a skyscraping 667.9 ft. tall, almost a full 5/8 wavelength in height. As advertised, KOA gets out to some 38 states, and probably more. KOA began broadcasting in 1924.

Back in the late 1970s and early 1980s, I lived a mere 10 miles southeast of this transmitter, out in the rolling eastern plains of Colorado near the town of Elizabeth. I worked in Denver, and would drive past this tower every day (or night) on the way to and from work, often seeing mule deer or prong-horned antelope. Coming from the east, a long hill descended down appropriately-named Hilltop Road, ending at Colorado Highway 83 which ran past the tower. Headed to work one night for the graveyard shift during a blizzard, at midnight I remember becoming disoriented in the whiteout and losing control while descending that hill, shooting straight across highway 83 and through a barbed wire fence, coming to rest in the field right next to the KOA tower. Ah, memories.

KOA is a tough catch here in western New York with nighttime interference from sports stations WKGE-850, Johnstown, PA  (10KW), at 199 miles, and WKNR-850, Cleveland, OH (4.7KW), at 235 miles. Interestingly, on my cross country trip each year I start to hear KOA at night consistently once I get west of Ohio and into Indiana, and under the 1200 mile distance range. I find there's something brick-wallish about that 1200 mile distance in mediumwave DXing.

WWL-870, New Orleans, LA (50KW), 1136 miles, is also appearing almost daily on the 6AM trip. WWL has a two tower antenna array, oriented south-north with major lobes to the northwest, and northeast. The northeast lobe points directly at me. Each of WWL's towers is a full 1/2 wavelength tall. With 3.3 dB gain in my direction, it pumps a healthy effective radiated power of 106KW right up a pipeline to New York. WWL's transmitters are located approximately 2 miles southwest of Estelle, LA, in the Jean Lafitte Preserve, a wetlands. All that water undoubtedly helps too. WWL has been in operation since 1922, predating KOA by two years.

Apparently the winter DX season is upon us once again.