Electronic Filing
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MB E-Filing Site
These FCC/MB forms MUST be electronically filed:
FCC Forms 301, 301-CA, 302-CA, 302-FM, 302-DTV, 302-TV, 303-S, 314,
315, 316, 318, 319, 323, 323-E, 337, 340, 346, 347, 349,
350, 381
EEO Forms 395-A and 395-B have been suspended by
Commission Order FCC 01-34.
CDBS Users Guide or call (202)-418-2662
CDBS System Status
Call Sign Reservations & Authorizations
for broadcast
station call signs
Antenna Structure Registration via ULS
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Easy, one-stop access to all online U.S. Federal Government resources
www.USA.gov
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AMwave
Wavelength Calculations to 30 MHz
A Fortran POST CGI example
This program receives an input frequency (up to 30000 kHz = 30
MHz) and calculates the corresponding wavelength of that signal.
Amplitude Modulation (AM) is generally used for transmissions
below 30000 kHz (or 30 MHz). Below 30000 kHz may be found the
Citizen's Band radio service, shortwave international
broadcasters, AM radio band broadcasts, amateur radio bands,
radionavigation beacons, and longwave broadcasting (the last only in Europe).
The source code for this program (HTML and Fortran CGI) is available for
download. AMwave uses the POST method to receive data, reading the
input string from standard input (STDIN). To retrieve the STDIN, we
use a READ statement (usually on unit 5 for STDIN) containing an END statement,
which executes once the end of the input string has been reached.
The STDIN information is saved into a character string which is
subsequently parsed to retrieve the name=value data pairs sent by the form.
FORTRAN:
- In this example,
the HTML output is established by the statements
write(6,55)
55 Format("Content-type: text/html"//)
This code must be placed before any HTML statements are written
to output. (Yes, you can change the Format statement number.)
The two // are VERY IMPORTANT! Also, note the placement of the "
quotation marks. Compare to the corrsponding C language statement
printf("Content-type: text/html\n\n");
- For HTML OUTPUT, the HTML tags are contained inside
Format statements, as shown in the example Fortran code.
BE SURE to have the usual HTML ending tags, or you may not see
any HTML output or receive an execution error code.
- Carefully watch use of ' and " in Format statements:
it's too easy to miss one ' or " or add too many.
- When generating output, statements must be no longer
than the 72 character limit in Fortran 77. Another Format
statement or a continuation character in Column 6 may be
used for longer statements.
- A CGI can output a new HTML form, or call a CGI.
The Fortran program can also incorporate subroutines, called in
the usual manner, although none are needed for this example.
- Fortran carriage control characters are unneeded when
generating HTML output. Use the HTML tags to perform this function.
However, to keep the browsers' source code view tidy, you can include
returns at the end of HTML lines:
write(6,111)
111 format(" HTML text here! " /)
- The program has not been optimized. There certainly
are better ways to do some of the tasks or changes
which could be made to reduce the code,
but it's not necessary for this simple example. Please note that no
Fortran or CGI library functions were used in the preparation or
execution of this example. The program was designed as a
stand-alone CGI.
- A GET method CGI example (COLORIT)
and a combined GET/POST example (Doppler-Shift)
are also available for your review.
Dale Bickel
Senior Electronics Engineer
Audio Division, Media Bureau
Original page February 1999; revised March 25, 2002
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