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.


Field Strength Calculator One: Update 1.0054

The latest update to Field Strength Calculator One has corrected the About window and incorporated various cosmetic updates. Also included are further refinements to the accuracy of the field strength calculation and distances.

For those new to Field Strength Calculator One, the program returns expected received field strength in millivolts per meter and dBu (also known as dBµV/m), based on ground conductivity, earth dielectric and several other input constants. It also displays the distance to the radio horizon and the signal path loss in dB, along with several more technical parameters. The resulting output of Field Strength Calculator One should be accurate in most cases to a couple of percent in the longwave and mediumwave bands. It compares favorably to ITU program GRWAVE and currently available FCC Ground Wave Conductivity graphs.

The original Field Strength Calculator One article was published on RADIO-TIMETRAVELLER in December, 2012.

For further information on how field strength is calculated see the Field Strength 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 FieldStrengthCalculatorOne.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.

Click image to enlarge.