RADIO-TIMETRAVELLER Maps #2

50 Kilowatts Night - U.S.

Our next map depicts all 50 kilowatt stations broadcasting during nighttime hours in the United States. 98 stations are represented. Black flags indicate allocations in the nighttime service class, pink flags the unlimited service class (24-7). The FCC defines service classes as DAYTIME, NIGHTTIME, UNLIMITED, and CRITICAL HOURS (the first two hours of daylight after sunrise and the last two hours of daylight before sunset). Data is from the 4-24-12 FCC database.

Representative antenna pattern plots are also shown.

Here are the statistics.

59 stations are Class A. 39 are Class B. 0 are Class C. 0 are Class D.

50 are located east of St. Louis, 48 are west of St. Louis.

51 are "W" callsigns. 47 are "K" callsigns.

The 98 stations broadcast using 269 towers.

30 stations broadcast an omni-directional pattern (single tower). 68 broadcast a directional pattern (multi-tower).

1 station is on the FCC "Silent" list: WDCD-1540.

If we divide the western hemisphere MW broadcast band in half (the center is at 1115 KHz), we have an equal number of MW channels below 1115 KHz and above 1115 KHz. There are 31 nighttime 50KW stations broadcasting above 1115 KHz. 67 broadcast below 1115 KHz.

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RADIO-TIMETRAVELLER Maps #3

1 Watt At Night - U.S.

The ultimate DX. How good (or lucky) a DXer are you? Have you ever tried for extremely low power AM stations at night?

Every night, 15 stations across the U.S. transmit with an output power of only one watt. How far does one watt travel normally, let's say under static conditions during the daytime? I'm glad you asked.

One watt into an omni-directional antenna (1 tower), over medium ground conductivity (8 mS/m), will get you out 10 miles, at which point the signal enters the "fringe" area of reception (0.15 mV/m and less). A good receiver will hear somewhat farther than that. At night, and using a directional pattern, who knows how far that signal will travel? All things are possible.

-----------------------------------------------------------CallSign Freq Power Class Location -----------------------------------------------------------WCKB 780 1 D Dunn, NC WRFM 990 1 D Muncie, IN WHFB 1060 1 D Benton Harbor-St. Jo, MI KLEY 1130 1 D Wellington, KS WGAB 1180 1 D Newburgh, IN WSQR 1180 1 D Sycamore, IL WPGR 1510 1 D Monroeville, PA WENG 1530 1 D Englewood, FL WJJT 1540 1 D Jellico, TN KBOA 1540 1 D Kennett, MO WBNL 1540 1 D Boonville, IN KLKC 1540 1 D Parsons, KS KDYN 1540 1 D Ozark, AR WZRK 1550 1 D Lake Geneva, WI WSRY 1550 1 D Elkton, MD
Here's some statistics for our 15 one watt stations, taken from the 5-27-12 FCC database:

All 15 are Class D.

12 are located east of St. Louis, 3 are west of St. Louis.

KLEY-1130, Wellington, Kansas, is the most westerly, leaving no 1 watt stations from there all the way to the west coast.

11 are "W" callsigns. 4 are "K" callsigns.

The 15 stations broadcast using 24 towers.

11 stations broadcast an omni-directional pattern (single tower). 4 broadcast a directional pattern (multi-tower).

1 station is on the FCC "Silent" list: WZRK-1550.

Interesting to note: 5 of the 15 are on the same frequency - 1540 KHz.

The lowest powered daytime station in the FCC's database broadcasts with 135 watts.

The most interesting broadcast pattern is that of WRFM-990, Muncie, Indiana. This station broadcasts using 6 towers. Its pattern projects generally to the north, covering Muncie and Delaware County as shown in the radio-locator graphic. WRFM-990's daytime power is 250 watts.

View the original article here

RADIO-TIMETRAVELLER Maps #1

50 Kilowatts Daytime - U.S.

Something new here on the blog - RADIO-TIMETRAVELLER Maps. On occasion I will present a map of interest to the mediumwave DXer. Maps and charts are generated by the Radio Data MW program. Here is the first one. Data is from the 4-24-12 FCC database.

The map depicts all 50 kilowatt stations broadcasting during daytime hours in the United States. 248 stations are represented. Yellow flags indicate allocations in the daytime service class, pink flags the unlimited service class (24-7). The FCC defines service classes as DAYTIME, NIGHTTIME, UNLIMITED, and CRITICAL HOURS (the first two hours of daylight after sunrise and the last two hours of daylight before sunset).

Representative antenna pattern plots are also shown. As you can see, not all are omni-directional as might be expected for 50KW stations. Obviously due to map size constraints, a number of station flags overlap, as do their patterns. Thus, for example, you see KXEN-1010, St. Louis, MO, highly directional, sits under KMOX-1120's omni-directional pattern.

Now, some statistics.

60 stations are Class A. 157 are Class B. 0 are Class C. 31 are Class D.

134 are located east of St. Louis, 114 are west of St. Louis.

137 are "W" callsigns. 111 are "K" callsigns.

The 248 stations broadcast using 628 towers.

103 stations broadcast an omni-directional pattern (single tower). 145 broadcast a directional pattern (multi-tower).

4 stations are on the FCC "Silent" list: WSJC-810, KYWN-890, WQOM-1060, WDCD-1540.

If we divide the western hemisphere MW broadcast band in half (the center is at 1115 KHz), we have an equal number of MW channels below 1115 KHz and above 1115 KHz. There are 85 daytime 50KW stations broadcasting above 1115 KHz. 163 broadcast below 1115 KHz.

The last graphic is a plot centered on the geographic center of the contiguous U.S., near Lebanon, Kansas. It shows the distribution of 50KW daytime stations radiating out from this location, using a scale of 2000 miles. A vague outline of the continental US can be detected, with 4 satellite 50KW stations towards the northwest (Alaskan stations), and a solitary 50KW station to the southeast in Puerto Rico (WKVM-810).

Hope you enjoy the map and chart. Look for more interesting maps and statistics to come.

View the original article here