V-Soft Communications Propagation & FCC Allocation Software Broadcast/RF

Professional Broadcast Engineering Software

V-Soft Communications Propagation & FCC Allocation Software Broadcast/RF



With Expanded LPFM Features
Click here for FM Allocations Software Introduction and demonstration Videos
Now with the 2020 US Census
Feature Rich!
(New Features List)

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FMCommander combines the resource tools of contour-to-contour and FCC separations studies with instantaneous interactive maps. You can find new ways to upgrade stations or to move transmitter sites under short space.  The program’s contour-to-contour search procedure is designed to be used for non-commercial or commercial FM station allocation studies, boosters, translator studies and low power FM.

This professional level computer program offers a mapping engine that uses the same polygon mapping database as our Probe and AM-Pro programs.  FMCommander produces detailed atlas-like FCC coverage maps with contour overlap and FCC minimum separations.  With drag and drop editing and labeling, the user can assign colors to labels, use automatic text boxing, add arrows, and do multiple undo.

An antenna pattern editor automatically designs directional antenna patterns and it users drag and drop pattern field values.

FMCommander contains a handy profiler tool that will quickly produce a terrain profile graph between any two points clicked on the map.

When using the minimum separations screen, you can model the 70 dBu principal city service contour (or other contours of choice) at any point, simply clicking by the mouse. For a YouTube video about FMCommander’s minimum separations study click here.

FMCommander automatically calculates the population within a station’s service contour. The program comes with the 2020 block level, U.S., census population files

All mapping layers, such as county lines, political divisions, city names, lakes, rivers, AM towers and FM zone boundaries are included in the price of the program. Additional optional overlays include population scatter-grams, FCC tower database plotting that includes the FCC registration numbers, airports and railroads.

The following example is a contour-to-contour ‘interference’ screen showing that there is 3.2 km of incoming contour overlap to KUNY from KZSE, Rochester. (Years ago, this overlap was waived by the FCC.)

FMCommander SeparationsFMCommander provides fully customizable screens, map backgrounds, font selections and colors. (Click here to see the Main Screen using a dark background with multi-colored text fonts.)

The coverage map below is a “graphics only” capture from the program’s “Find Information” screen.

FMCommander MapThe example below, FMCommander shows a standard FM minimum spacing map using the FCC rules in section 73.207 and 73.215.FMCommander MapThe Separations Mapping screen is interactive.  If you click a given location with your mouse, the program will recalculate the study using the coordinates of your point as the reference station’s location. The minimum spacing circles are plotted at each relevant transmitter location and they define areas where another transmitter ‘cannot’ be located on a given channel.  The map above shows a relatively large area-to-locate in the lower half of Cape Cod making a drop-in channel possible. The minimum-separation-circles can also be filled with a color which makes the drop-in location pop out to the eye of the user.

For ‘contour-to-contour’ studies, FMCommander’s text displays and print-outs show the amount of prohibited contour overlap or clear space in two, easy to read, columns labeled “In” for incoming overlap and “Out” for the overlap the reference station may cause to other stations. The amount of Contour Overlap is represented by the distance between the appropriate interference contours and protected contours. (A map of the interference and protected contours is shown below.) Lack of contour overlap, received or caused, can be confirmed when the display shows no negative figures (overlaps) in the “In”, incoming column and no negative figures in the “Out” column. Negative distances, colored in red, indicate the intrusion of an interference contour over a protected contour of another station.

When placed in the “detailed overlap” mode, FMCommander automatically checks 180 degrees of arc of the interference and protected contours of the reference station.  If overlap is found ‘along any azimuth’, the call letters of the affected station will turn red in the listing and the greatest amount of contour overlap will be shown in the table.

FMCommander MapIn the example above, KUNY has a 3.2 km incoming overlap with KZSE. The map screen above maps out the actual overlap.  Click here to see a complete allocation map study for KUNY, created with one click of the “Allocation” icon.

FMCommander interfaces transparently with V-Soft Communication’s FCC based, 30-arc-second, or 30-meter high ‘rez’ digital terrain databases.  For maximum agreement, these are the actual databases in daily use at the FCC Media Branch. Other terrain elevation databases that can be used by the program include the V-Soft U.S.G.S. 3 arc-second, the National Elevation Datum (NED) 3 second or 30 meter terrain elevation databases, the V-Soft cloud-corrected, shuttle, 3-arc-second Radar Topography Mission database and the GLOBE 30-arc-second terrain database. The program quickly calculates the maximum power allowable in any direction. The effect of terrain attenuation and directional antenna is automatically applied.

FMCommander displays the station’s operating parameters when you click on the call letters (either from the “Main Screen” table or the station list on the “Find Station Information Screen.”)  You can resize this screen or any of the FMCommander map screen windows by dragging a corner.

FMCommander’s powerful, interactive antenna pattern editor lets you change the fields values along various azimuths by dragging and dropping a pattern point from the pattern screen. All patterns can be saved to file for future use or sent to the printer.  If FMCommander sees a station in the FCC database that uses a directional antenna, it will apply that pattern to its contours.

FMCommander prevents you from making a mistake, such as producing a station that exceeds the maximum distance service contour for its class.  An example of one of the helpful pop-ups is shown below:


An extensive help-screen pops up to remind you of the operating instructions as well as provide tables for, maximum power and antenna heights for classes. These tables also provide such information as the maximum distances of allowable protected service contours for all classes and, the minimum distance allowed for section 73.215 short-spacing between classes.

If you are working with a translator, either fill-in or non-fill-in, FMCommander has some special routines that will tell you whether your power on a given radial azimuth is over the maximum according to the rules. For the non-fill-in translator studies, a pop-up reports the azimuth of the bad radials and what the maximum power should be. The program always knows which zone the translator is in.

In addition to contour-to-contour interference checks for non-commercial educational FM studies, FMCommander features an array of convenient routines to determine if interference is caused to full-service channel-six TV, as spelled out in Sec 73.525 of the Commission’s rules. The program will map the channel-six interference area and the protected grade B contour of channel-six TV station. As a part of this process, FMCommander searches the television database for channel-six stations within the cut-off distance. The protected grade B (and grade A) contour for all such TV-6 stations is automatically calculated as is the allowable signal of the FM station at such contours.  The program will determine maximum power when the FM station is co-located with a channel-six television station. For a video on a few of the ‘Find Information Mapping Screen’s’ features, click here.

FMCommander features an automatic “tracking” routine for searching for open channels. Simply place the program it in the “Seek” mode and let it do the searching for you.

The “C0 downgrade” feature will automatically downgrade all class C stations with an HAAT below 450 meters to the C0 class. This allows the user to find drop-ins and upgrades that require C0 downgrades to fit. All stations capable of being downgraded to C0 are suitably labeled with an underline of the call signs or the light blue color separation circle for maps.

At the click of your mouse, FMCommander will perform a “Protected Zones” report.

FMCommander Protected Zones ReportFMCommander’s separations tables uses the FCC’s revised I.F. separations, which include the channel 253 to channel-six TV relationship. The program automatically uses the latest Canadian treaty separations and relevant Canadian protected contour values. Minimum separations from the 1994 Mexican treaty, as revised in 1997, using international class classifications, are applied when there is a relationship with Mexico.

The program uses the same FCC database that is in major use at the FCC for all our V-Soft programs. FMCommander’s clear, straight-forward printouts feature the parameters of the station being checked, (reference station) printed in the heading. The 60, 57 or 54 dBu protected contour distances are predicted from the Commission’s F(50-50) table, while the 40, 54, and the 100 dBu interference contours are derived from the Commission’s F(50-10) table. All contours are in kilometers and are predicted using the actual FCC TVFMINT FORTRAN algorithm as published in FCC report No. RS 76-01 by Gary C. Kalagian, so the numbers you get will match with what Commission engineers see when an application form is reviewed. In addition to the columns showing measures of incoming and outgoing contour overlap interference, FMCommander’s printouts feature the radiated power, antenna HAAT & COR AMSL, distance to, azimuth to, reverse bearing from and geographic coordinates of each pertinent station. Also included is the exact distance of the database station’s protected and interference signal contours. The print-outs include information on whether the station operates as an old rule directional or new rule Sec.73.215 directional. The print-outs also list information on antenna polarization, beam tilt, licensee ownership, file and facility numbers and cut-off dates.

Click below for a PDF file example of FMCommander’s various printouts.

Contour-to-contour printout (PDF)

Standard spacings printout (with comments, PDF)

Standard spacings printout (Long form, PDF)

Spacings Printout with graphic (PDF)

Standard spacings preclusion printout. (PDF)

The integrated database screen (Station Filer) allows the user to easily access, change or correct the FCC’s database information. Multiple key searches of the full FCC database searches can be performed allowing the user to direct the collected list to screen, to a printer or to a text file. The “Filter” can be used to select those stations that match the query criteria within a user’s set distance. For a screen listing, the user may click any of the stations listed on screen to see the entire record.  Click the “Station Filer” link (above) to see the Station Filer screen. If a station has a directional antenna pattern, the “Pattern” button will be visible.  Clicking this button will bring up an azimuth pattern display plotting the pattern along 36 or 360 points with any ‘extra’ pattern points that may be included.  The extra pattern points will also be shown in the display’s tabular field value listing.

FMCommander has an optional Internet Mapping Module, that allows synchronization and interactivity with a number of internet map sites, including Google Earth on which the program can plot a station’s coverage or ‘area-to-locate’ map.

The new WatchDog™ option has been completely updated. This module allows the user to prepare a list of addressees and stations’ call signs to be used in automated studies. Full channel-studies containing Sec. 73.207 separations reports and Sec. 73.509 contour-to-contour reports, for each station on the list, can be sent through automatic email attachments. he entire list of emails can be sent automatically on a recurring basis without user intervention. The screen shots, seen below, show the module’s main and setup screens. The program is opened by a menu item on the FMCommander Mainscreen.


FMCommander was created by senior engineering consultant Doug Vernier.  The newest release adds many new and powerful features.  V-Soft Communication’s programs are widely used by technical consultants and broadcast engineers throughout the U.S.  The program is now packaged with the official 2020 group block US Census population data and FCC’s most recent FM database, which includes channel-five, six and LPTV television station data.

Our telephone and email technical support program provides support for FMCommander and all the other V-Soft Communications programs. Users in the support program can receive regular access to database and program updates as they happen. Fresh database downloads are available every day.

For more on FMCommander please give us a call at 319-266-8402 or contact us online.

For a price quote or more information on any of V-Soft Communications' software products please contact us by email or call (319) 266-8402 or (800) 743-3684.

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