Saturday, January 24, 2015

2015 US And Canadian Pattern Reference

Greetings, and Happy 2015!

The 2015 US and Canadian mediumwave broadcast pattern reference is now available for download. You'll find the links at the upper right of this page.

I've spent much of the last year working on mediumwave pattern mapping, when time permitted.

Included is a complete set (daytime and nighttime) of GoogleMap-based, HTML-driven maps which show the most current pattern plots of all licensed US and Canadian mediumwave broadcast stations from 530 - 1700 KHz. The set includes all frequencies for the indicated services: Unlimited, Daytime, Nighttime, and Critical Hours. Individual maps are grouped by channel frequency: 540, 550, 560 KHz, etc. Data for the plots in this offering is based on the current FCC and Industry Canada databases available at the time of its creation (January 22, 2015).

THE UPDATES

1. Groundwave pattern maps have been streamlined and made more accurate.

2. This current set of maps uses an enhanced version of the FCC's M3 Ground Conductivity data base. Many errors in the original database were found, things like segments not joining properly, missing data, odd values for the Canadian land mass, problems with Alaska and Hawaii. I have corrected all these, plus added the conductivity data for the five Great Lakes bodies of water which were missing from the original database. Even little Lake St. Clair near Detroit has been incorporated.

3. I have written from scratch nighttime skywave mapping code using the standard FCC formulas, and now nighttime skywave pattern maps are newly available in this download. Nighttime signal patterns represent the standard SS+6 (sunset plus 6 hours, or approximately midnight), 50% signal probability at 0.25 millivolts per meter (48 dBµV/m, a.k.a. dBu). Note that nighttime reception of signals out beyond the depicted pattern is very possible, and in fact likely for the DXer. The maps represent a signal strength between distant and fringe, a level generally easily received at night on most portable radios. I have chosen this signal level to give a good representation of what should be fairly easily received by most DXers on an average evening. The nighttime signal probability of 50% means that the signal will be received at this level approximately 50% of the time at that location for the sunset+6 hour time. Also included in the nighttime map series is a web-based HTML table listing all nighttime stations in the US and Canada. It has clickable links which will take you directly to the FCC pages for that station (US stations only).

4. The daytime map series shows expected groundwave coverage patterns for Unlimited, Daytime, and Critical Hours operations. Daytime signal patterns represent groundwave coverage out to the 0.15 millivolts per meter contour (43.5 dBµV/m, a.k.a. dBu). Note that daytime reception of signals out beyond the depicted pattern is very possible, and in fact likely for the DXer. The contour line represents a signal strength at the station's fringe distance, a level usually received on a sensitive portable radio with a low ambient local-noise level. I have chosen this signal level to give a good representation of what should be fairly easily received by most DXers during sunlight hours. Also included in the daytime map series is a web-based HTML table listing all daytime stations in the US and Canada. It has clickable links which will take you directly to the FCC pages for that station (US stations only).

5. The Industry Canada Canadian database has now also been included in the daytime and nighttime pattern maps, showing each Canadian mediumwave station and its broadcast pattern. A lot of time was also spent incorporating the Canadian engineering data and coding up software to process it. Unfortunately, no Mexican patterns are available. I have elected to exclude them from the maps as the Mexican government does not provide technical engineering data via the internet. FCC Mexican data is redundant and inaccurate at best, though I may at some point offer some pattern maps of what is available.

THE DOWNLOAD

Downloads are at upper right as always. Remember the download link changes each time I publish these files, so always come back here to get the latest files. Files at upper right are current as of the January 22, 2015 FCC and Industry Canada databases.

Be sure to read the readme.txt file contained in the .zips for tips on how to use the maps.

Click the image for a full-sized map representation.

760 KHz at night. 0.25 mV/m, 50% reception level.

Saturday, September 13, 2014

Fall Season, 2014

Friends,

I must apologize for no blog posts this last year. I have gotten away from the writing due to other outside activities beyond radio, but perhaps will do some this fall or winter.

Getting ready for another cross country trip again (east coast to west coast), and will be taking the radios with me, as always. Will try to make some notes on any interesting receptions.

Have bought a Radio Shack 20-629 synthesized world AM/FM/SW receiver (PL-505 clone) over the summer and have been enjoying it very much. It has characteristics much like the Tecsun PL-600. It is a fun radio to use.

In other news, I've been working on mapping nighttime signal patterns over the last year and other program coding for the FCC database. I also have the full Industry Canada AM database unpacked and coded, which allows complete daytime and nighttime pattern maps. I am getting close on the skywave coding, and will shoot for some downloadable files on this blog in the next few months, as well as a groundwave pattern update.

The latest run on the FCC database, dated today, 09-13-2104, shows:

US Mediumwave:
4710 facilities. (FCC indicates 4715, though 5 of these are officially deleted entries).
300 facilities registered to transmit IBOC digital.
94 facilities are silent.

The latest run on the Industry Canada database, dated today, 09-13-2104, shows:

Canada Mediumwave:
161 facilities. 14 more (making 175 total) are listed as provisional and may or may not be operational.

More to come.

Take care and good DX to all,

Bill
RADIO-TIMETRAVELLER

WWL-870 nighttime (50 KW) and its competition to fringe .15 mV/m 50% signal probability

Thursday, September 26, 2013

New US Mediumwave Files Uploaded

New US mediumwave files have been uploaded for you. They represent the latest FCC database dated 09-24-2013. Find them at the upper right hand column of this blog under LATEST US MEDIUMWAVE FILES. All files are produced by the Radio Data MW program.

1) US Mediumwave Data 540-1700 KHz

Files are in HTML format and contain every licensed US station in the FCC database. They can be viewed in any browser. In the .zip you will also find a comma-separated-values (.CSV) file of all stations which can be viewed in spreadsheet format by programs like Excel. A table file showing all stations in grid format is also included. The HTML files contain clickable links which will take you to various informational pages for each station within the FCC web site.

2) US Pattern Reference 540-1700 KHz

Included is a complete set of GoogleMap-based, HTML-driven maps which show the most current pattern plots of all licensed US mediumwave broadcast stations. The updated set now shows patterns calculated at the 0.15 millivolt per meter (fringe) contour level based on actual US ground conductivities. It includes all frequencies for the indicated services: Unlimited, Daytime, Nighttime, and Critical Hours. Individual maps are grouped by channel frequency: 540, 550, 560 KHz, etc.

Note that these maps show expected groundwave coverage patterns for each service, not skywave. Skywave maps can be produced by Radio Data MW, but are better printed out on a station-by-station basis. Use of the program is required.

HOW THEY ARE PRODUCED

Using the actual FCC database files Radio Data MW will auto-generate an interactive HTML pattern map, showing the pattern plots for all stations included at the discretion of the user. A complete set of mediumwave pattern maps can be generated. Radio Data MW generates a real pattern plot based on ground conductivity, ground dielectric constant, and can display actual (but approximate of course) signal level boundaries for Local, Distant, Fringe, Extreme mV/m levels, or any custom mV/m level chosen by the user.

The online Google Maps API is used to generate and plot each station on a map of the US. An accurate flag pin is placed at each transmitter location, and in satellite view may be zoomed in to see the actual transmitter site. Map flags are color-coded to indicate Unlimited (light red), Daytime (yellow), Nighttime (black), and Critical Hours (grey) services. Each flag has a tooltip-type note, and when hovered over with the mouse will display a note on the station.

A pattern plot for each station is generated and displayed. Each pattern is calculated using standard formulas used by the FCC to compute the base values at one kilometer, and field strength formulas at distance based on the works of many people over the years. See Field Strength Calculations: A History and Field Strength Calculator One, previously posted on RADIO-TIMETRAVELLER.

Finally, an accurate ray path can be drawn from all transmitters to a user-specified receiving location by inputting latitude-longitude coordinates. Super-imposed on the pattern plots, the ray paths show the listener where he or she falls on each station's pattern, a handy guide to knowing where you stand.

USING THE MAPS

Note again that these maps are web-based. As stated, they use Google Maps and thus require access to Google. In order to view them you need a connection to the internet.

Desktop browsers: Not a problem, all seem to work well. Maps have been tested in the Internet Explorer, Firefox, Chrome, Opera and Safari browsers. If using Internet Explorer, best results are had with version 10 or greater.

Phone or tablet browsers: Maps may work on tablet or phone browsers, but no guarantee is given. In testing I have found most of the browsers will not allow maps to scroll or pinch to zoom correctly. FIXED!! (Grab corrected replacement files at upper left). Note also that the maps, being script-driven and with many lines of code are very CPU-intensive, and may cause tablets or phones to choke.

These are the latest US pattern references available, and coverage is based on actual ground conductivities.

Hope you enjoy these files.

Click image to enlarge.

640 KHz, 0.15 mV/m fringe distance

Tuesday, August 27, 2013

Loop Calculator One: Update 1.0228

The latest update to Loop Calculator One includes various cosmetic updates to improve readability and understandability.

For those new to Loop Calculator One, the program will display detailed information about coils, including accurate inductance for short and long coils of many types. It is especially tailored for inductance calculations of polygonal-shaped mediumwave receiving loops.

The original Loop Calculator One article was published on RADIO-TIMETRAVELLER in March, 2012.

For further information on loop calculations see the Loop Calculations Series previously published on RADIO-TIMETRAVELLER.

DOWNLOAD

To download, see the link at the top of the right sidebar under LATEST PROGRAMS. The sidebar at the top right will have the most current link in case the program is updated. The link will change in the case of an update, so I would avoid copying and pasting it into a forum or other web page. Come to the main page of this blog instead.

INSTALL

Install is simple. Download the .zip file and unzip. Click on the LoopCalculatorOne.exe file to run. This program makes no registry changes and saves no data to your hard drive. It has been developed and tested in Windows 7. It should work fine in Windows Vista and XP environments, and Windows 8. It is written in the old standby Visual Basic 6.

Included in the .zip is a readme.txt file. Be sure to have a look. Also included is an American Wire Gauge chart showing wire diameters.

Click image to enlarge.