Radio station
A radio station is a site configured for
broadcasting sound. Traditionally,
radio stations have broadcast through the air via radio waves, a form of
electromagnetic radiation, but today many
stations broadcast via cable, local
wire networks, or the Internet
as well or instead of atmospheric broadcasting.
Often stations are linked in radio networks.
Radio stations are of a number of types. The best
known are the AM and FM
stations, both commercial and "public", or nonprofit.
Many other types of radio stations exist. These
include:
- base stations for
police, fire and ambulance networks
- military base
stations
- dispatch base
stations for taxis, trucks, and couriers
- emergency broadcast
systems
1. Download the free RealProducer and free RealPlayer from
RealAudio.
Note that both of these products have free
and commercial versions. The free
versions are completely adequate. You may have to hunt around
on the
RealAudio pages for links to the free
versions. But hunt around; they are
there.
2. In addition to these, you will need the
following:
* Pentium-based PC with 10 Mb of hard drive
space;
* a sound card that
is installed – that is, that can take sound in as well as
sound out. All sound cards come with installation
disks or CD, but usually it
isn’t necessary to install them simply to listen to sound
through the speakers.
* a good quality
cassette tape recorder – the best quality you can get – both
for making a high-quality audio cassette of your lecture
and for "inputting" the
audio into your sound card. Therefore, it should have a
"sound out" jack (often
called AUX ) or an earphone jack.
* a cable – usually
with 1/8 or "mini" jacks on either end – for transferring the
audio from your cassette recorder (analog) to the computer
through its sound
card (digital).
3. When recording the sound on the cassette,
be sure to get the highest
quality sound you possibly can get. There is some loss of
sound quality in
converting from the cassette tape (analog) to the .RM format (digital).
A
lecture that is audible in cassette format may not be
audible when digitized
unless it is a high-quality recording to begin with.
1. Connect the "sound out" of the
cassette recorder to the "sound in" (often
labelled MIC for "microphone) jack in your sound card,
with your cable.
2. After installing RealProducer,
open it. Press "cancel" when the New
Session screen comes up, and go to the main
screen.
3. Choose File – Recording Wizards – Record
from Media Device (your tape
recorder is the "media device").
4. Check the "Capture Audio" box
only. Press "Next".
5. Fill in Title, Author, Copyright,
Description, and Key Words appropriately for
your lecture. Press "Next."
6. For "File Type" press
"Single Rate for Web Servers". This is the smallest
size file you can create. This is important, as the
smaller the file, the less
information must be passed over the Internet connection, and so
the more
fluently the file streams.
With decent audio, this and the rest of the
settings create a file that is fine for
lectures. Press "Next".
7. For "Target Audience" check the
box marked 28.8 Kb modem. Again, this
creates the smallest size file, and it is adequate with
decent audio input. Many
students access the Internet only through a 28.8 Kb modem
from home.
Press "Next".
8. For "Audio Format", check the
box for "Voice Only." Again, this is
adequate
for lectures, and creates the smallest possible file. Press "Next".
9. For "Output File" and
"File Name", browse to the directory on your hard
drive where you want the .RM file to be created. The
Default is to your
desktop; it’s best to create it to a directory. Press "Next".
10. "Prepare To
Record" summarizes all your settings and gives you a chance
to back up and change any which are incorrect. If all
is OK, press "Finish".
11. When you are ready, set your tape
recorder to "Play" and press "Start" on
RealProducer. After about a second, you will begin to digitize the
file.
If you do not see any movement (yellow and
red bars) in the "Audio Level"
meter, your audio is not being received by the computer. I
have found this
occurs when the jack is loose, the tape recorder defective,
or – usually –
when the computer’s sound card has not bee properly
installed to receive
Sound In.
12. If all goes well, press "Stop"
on RealProducer when your lecture has
finished. RealProducer will take a
few seconds to produce your .rm file.
1. Upload your RealMedia
(.rm) file to a web server using FTP.
2. If more than one student at a time will
have to listen to the file, ask your
server administrator to install the RealMedia
extensions on your server. This
will make your server a "RealServer".
Now it will be able to stream your file to
many listeners at once, and each of them can be at a
different point in the file.
The older versions of RealMedia
files had the RA extension.. It was possible
to create a link to these files simply by putting the
name of the file as
filename.ra at the end of a normal HTTP link. .RA files could
also be easily
copied, just like HTML, GIF or JPG files.
Current RealMedia
files are .RM files. To link to them, you must create a
"pointer"
file. This makes it impossible to copy the file without special
software, and so is more secure.
Here is how to link to an .RM file, the kind
you will be making:
1. Create a pnm link to a file with a RAM
extension (.ram).
For example, I have a short .rm file called "Achebeanalysis.rm".
It is a
recording of me analyzing a paragraph from Chinua
Achebe’s novel Things
Fall Apart. I have uploaded this RealMedia
file to a RealMedia server named
edtech1.montclair.edu, and put it in my subdirectory, /furrg The full path to the
file, therefore, is:
edtech1.montclair.edu/furrg/Achebeanalysis.rm
The "pointer" file
looks like this:
pnm://edtech3.montclair.edu/furrg/Achebeanalysis.rm
Save this and call it Achebeanalysis.ram
2. Upload this to any web server. I have put
it on my regular web space, at
chss.montclair.edu/english/furr/media
So the full path to this .ram file is
chss.montclair.edu/english/furr/Achebeanalysis.ram
3. Create a link on any regular web page –
say, on the Homework page for
my "World Literature" course – just as you
would a regular HTML file, like this
http://chss.montclair.edu/english/furr/Achebeanalysis.ram
Now, when a student clicks on the link to
the .ram file, that student’s browser
will:
a. access the .ram file;
b. read it;
c. be directed to the .rm
file, on another server;
d. automatically call up RealPlayer, which the student
must have previously
installed; and
e. download the "buffer", or first few
seconds of the file, and automatically
begin to play the file over RealPlayer.
Audio Level may be adjusted three ways:
1. RealPlayer itself has a slide audio control.
2. If played through the computer’s
speakers, the speakers themselves will
have a volume control;
3. Windows 95/98 have
a volume control, in the form of a small yellow
"speaker"
icon on the working tray (right side of the Windows taskbar).
(If this icon is not visible, go to
Start-Settings-Control Panel-Multimedia-
Settings-Multimedia
Properties-Audio-Playback, and check the box marked
"Show volume control on the
taskbar").
There are many Streaming Audio lectures and
other recordings already freely
available for linking to or even for downloading, on the web,
and more all the
time. The best way to locate them is to use one of a
number of specialized
Search Engines. Here are some of them:
1. "Snap.com". You can use this
right from RealPlayer. Go to the "View"
pulldown menu and make sure "Search" is checked. A
text form window is
displayed into which you can type keywords for the kinds of
files you want.
This will connect your web browser to the
search facility at
http://real.snap.com. You can also just go
directly to real.snap.com in the first
place.
2. RealAudio has a guide to Streaming Audio
and Video files at
3. The Altavista
search engine has an Audio and Video Search facility. Click
on the "Images, Audio/Video" tab on the home
page,
Other search engines also have facilities
for searching for Streaming Audio.
These are the ones I have found most helpful