Technical Requirements for LPFM Station Operations and
Guide to Filling Out FCC Form 318 Section V: Engineering Specifications
Prepared in an effort at
helping the "non-technical" among us in understanding the LPFM application
[Technical Requirements for LPFM Operation]
[How much will it Cost?]
[All About Antennas]
[Navigating through the FCC Application Process]
Technical Requirements for LPFM Station Operation
A word about
Obviously, the height of the location that you build
your transmitter on is important. If you have a choice, get the antenna
up as high as possible. It should be noted that while not optimal,
perfectly adequate coverage can be gotten from a twenty or thirty foot
antenna located on a residential rooftop, all other things being equal.
Depending on the antenna you choose, It can look less obtrusive than
even a standard TV reception aerial.
Also keep in mind: While it is best and cheapest to
have your studio and transmitter at the same site, nothing needs to be
at the transmitter site except for the transmitter, electric power, the
antenna, and some sort of receiver for broadcast audio- either via
telephone lines or by radio link.
This will add to your costs, but we are currently
researching options that are as cheap as $500-$1000 for accomplishing
this goal. This way, your studio can be at the most convenient location,
and your transmitter can be a relatively unobtrusive appliance in
Your average hundred
watt transmitter is a little bigger than a breadbox, and can be stuck on
a shelf near a regular electrical outlet.
While the FCC hopes that LPFM stations will have relatively
simple operations, nonetheless the Commission is requiring LPFM stations to meet
most of the same legal and technical requirements that all educational,
noncommercial FM stations must meet. Most of these operating requirements are
simple and inexpensive, but they include having to participate in the EAS
(Emergency Alert System) by installing special equipment, and keeping such
records and logs as the FCC might require to ensure that your transmitter is
operating properly without causing interference. [For detailed up-to-date
operating requirements of non-commercial public radio stations, contact the
National Federation of Community Broadcasters.]
There are three main technical elements that are needed to
operate a radio station:
• A physical place to hang an FM antenna.
• A place to install a transmitter.
• A location for your broadcast studio.
To apply for an LPFM license, you MUST have a location to
install your antenna and transmitter. You do not need a studio location to fill
in the application. But eventually you will need a studio site before you go on
The antenna and the transmitter are your broadcast
transmitting elements. This is where your signal
originates and goes out into the airwaves. These two pieces of equipment are
usually (but not always) installed in proximity to each other. For LPFM, the FCC
requires that your transmitter and antenna be located within 10 miles of where
your organization functions.
An FM antenna is similar to a television antenna that
you might put on a roof to improve TV reception. It can be installed on a mast
or pole secured to the roof of a building, on a freestanding tower, or on some
other structure that elevates it above the ground. This can be anywhere from 100
to 1000 feet or higher, if it is on a hill or mountain.
The signal reaches the radiating
elements of the antenna through a special cable that is connected to the
transmitter. The cable leaves the transmitter and must be long enough to reach
the antenna, feeding the broadcast signal.
The transmitter is generally located in a closet or room on or
near the roof, somewhere else in the same building as the antenna, or in a shack
or building on the ground under the tower.
The antenna does not need its own power.
It gets its power from the transmission signal and is designed to be outside.
The transmitter needs electricity and must be inside,
protected from the weather.
Both your antenna and your transmitter must be ětunedî to the
frequency you are assigned by the FCC, so that the signal is broadcast on the
correct channel and only that channel. When you purchase your transmitter, you
will tell the manufacturer your frequency and it will arrive pre-tuned or with
instructions on how to tune it. LPFM antennas are broadband, and will be able to
transmit from any frequency you are assigned. The manufacturer will tell you if
it needs to be pre-tuned.
The programs you broadcast originate from a control room, also
called a broadcast studio. This is the place where the microphones, CD players,
cassette machines, and other equipment is located so people can produce live and
recorded radio programs. Most commercial and many non-commercial public radio
stations have several control rooms and studios, where they can record, edit,
mix and broadcast programs all at the same time. But a radio studio does not
need to be either expensive or complicated to sound good and be easy to use.
You do not need an FCC license or
any permissions to build and run a radio production studio.
You do not need any kind of special room.
The studio can be in its own dedicated room, in a closet, or even in a corner of
a room that is used for other purposes. The main condition is that it be quiet
enough that the room noise does not overly distract from your radio broadcast,
or be too confusing to listeners.
Consumer quality equipment, such as CD players and cassette
decks, is adequate for most broadcast uses that you might have.
However, if you intend to learn or teach more advanced radio
skills or production techniques, or use some equipment very heavily, you might
want to invest in professional quality equipment which is more expensive but
designed for long-term durability.
To be heard on the radio, the programs that you originate in
your studio must travel to the transmitter in one way or another, by cable, or
through the air. Try to locate your studio as close to the transmitter as
possible. If you can, put the studios in a room nearby where the transmitter
is located. Then, connecting the equipment in your studio to your transmitter
might only need some cables.
If this is not possible, try to put your studio in the same
building as the transmitter. Often, studios are located on one floor of a
building and the transmitter is on the roof. The cable between them is run
through an elevator shaft, stairway, or other conduit that connects them.
You might have to locate your studio in another building or
some other place distant from the transmitter. In this instance, you will
need an STL Studio to Transmitter Link that will connect your program signal
to the transmitter in a reliable way.
There are several ways to set up an STL. One of the simplest
is to get a land line to provide a dedicated connection between your studio and
your transmitter. This is arranged through a phone service provider and is
similar to getting a regular dial-up phone line, but with better quality. There
are also other technical solutions, such as using a microwave link, which
requires a different kind of license from the FCC. The most cost-effective and
reliable method for your station will depend on the particular circumstance and
location of your facilities. [You will probably need an engineer to help set up
When these three elements - antenna, transmitter, and studio
-- are hooked up and turned on, you're on the air!!!
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How Much Will It Cost?
The technical costs for an LPFM station fall into three
categories. In each area, there are great variables, but you can use these as
general guidelines for costs.
the Engineering Section of the Application
This is a relatively simple form to fill out, but it requires
being able to answer a number of specific technical questions required by the
FCC. This Guide will help you, but if you decide you cannot or do not want do
this on your own, we recommend that you hire a qualified broadcast engineer to
fill out this section of the application. Engineers will already know the basic
rules for geographic and frequency separation and have the software on hand.
If you hire an engineer, he/she does not have to be local.
They do not have to visit you to fill out the application, as long as you
provide them with accurate information. The same technical rules apply across
the country, and they can run the computer program no matter where you or they
live. However, if your location has special conditions, or if you need an
exhibit or additional technical work, be prepared to pay more.
Transmitter and Antenna
By itself, an LPFM 100 transmitter will cost $3,500 -
6,500, and an antenna will be $1,000 - 2,500. In addition, you will need
coaxial cable to connect them, some related monitoring equipment, and mounting
hardware. You might need a rack or other furniture for your transmitter, and
there are always unanticipated costs that are be required out of pocket.
All the equipment is produced by different manufacturers, and
you can purchase each piece individually. But equipment dealers will be
putting together transmission packages so you can order everything you need for
your transmitter and antenna at the same time. Based on such variables as
how far away your transmitter is from your antenna, and if you will be
broadcasting in monaural or stereo, you should expect a complete
transmitter/antenna package to cost $5,000 - $15,000. In most cases, buying a
complete transmitter/antenna package individualized for your location will be
the most cost effective way to get what you need.
Broadcast Studio Equipment
Unlike transmission facilities, there is huge variety in what
you may want to put in your studio. You can put together studios with
consumer-grade equipment that is purchased or donated, or standard professional
quality equipment that costs thousands of dollars.
It is likely that the most expensive single item you will
need to purchase is a mixing console, the piece of
equipment that allows you to mix microphones, CD players, and other music and
recorded sources together to go out over the air. A simple mixer can cost $350 -
$2,500 new. Everything else - microphones, CD and cassette players, headphones,
etc.-- can range wildly in price. If you are buying everything new, a modest
package might cost as little as $2,500. The price goes up from there. You will
pay more if you want all digital equipment, or plan to invest in a digital audio
workstation (DAW) for program production, which is a computer-based editing
Here again, there will be a range of packages available from
equipment dealers who will want to sell you stuff you wonít really need. You can
hire an engineer to help you with this, but since most of it is regular audio
equipment, you can get help from a friendly local musician, sound technician,
audiophile or radio producer who knows audio recording and would be pleased to
advise you about putting together an appropriate complement of studio equipment.
Hiring Broadcast Engineers
It is likely that at some point during your station
construction, you will need a broadcast engineer to assist you
with an on-site installation or facilities problem, such as transmitter testing
or installing an STL. You might want to make friends with one of the engineers
who work for the local commercial or public broadcast station. (Often engineers
will work for several stations at the same time.) Most of them will work on an
hourly basis for specific projects or emergencies, or on a contract basis for a
longer term project. Many of them might be willing to advise you as a volunteer,
or charge you only nominal fees.
You can also look for free or inexpensive help from other
local technical folks - amateur (ham) radio operators, musicians, producers,
computer technicians - people with technical expertise in related fields who can
provide the technical assistance you need. It isn't necessary that they be an
actual broadcast engineer to be skilled and knowledgeable about equipment
If you have an especially difficult technical problem, you
may have to bring in an outside "expert" from a professional engineering firm.
Be prepared to pay full non-commercial rates for such service, but don't
hesitate to negotiate.
There are engineering firms that will offer to set up your
station on a "turnkey" basis. That is, for a single fee, they will do all the
work and handle EVERYTHING, from filling out and submitting the application, to
ordering and installing the transmitter and building the whole studio. The
costs for such services are generally high. Because most LPFM stations will be
technically simple to construct, hiring a turnkey operator is probably not cost
effective. However, if you want to consider a turnkey operator, get several
bids. Use the cost guidelines outlined above for hardware, and add costs for
labor and overhead to provide a rough estimate of what the bid should cost. Be
sure the bids are within reasonable range.
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All About Antennas
[location is key][Mounting
the antenna][Find your coordinates]
Finding a Good
Antenna Location is the Key
To win a new LPFM license, your application will have to meet
both geographic and frequency separation rules. Determining your success depends
on where your antenna will be geographically located.
The rules determining if a new station will be licensed are
based on the existing allocations the FCC uses to grant FM licenses.
The place on the dial is called the frequency (i.e. 93.5 FM) but the FCC also
calls it a Channel - each frequency has an equivalent channel number. [The FCC
has a chart with the parallel frequency and channel assignments for the FM
Because FM radio has been in operation for decades, the FCC
has a well-established set of rules governing frequency allocation (though this
will radically change with digital broadcasting.). With LPFM they are changing
these rules somewhat, but most of them still apply. The rules are based on
protecting the signals of existing stations, so that new stations can only go on
the air if they do not create any interference to stations already on the air.
Basically, this means that the FCC draws an imaginary
geographic circle around every existing broadcast antenna, AND a protected space
between each FM frequency already assigned on the dial. Then they will try to
fit your station into the spaces between these separations. This is actually a
complex calculation that must take into account several interrelated factors,
including geographic location of the antenna, its height above average terrain
(because FM is line-of-sight, the higher an antenna, the further its signal will
reach) and the power of the signal (anywhere between 1-100 watts.)
Based on your proposed antenna location, the FCC will
determine if there is an available frequency. The new
stations will be licensed to operate anywhere they fit in the FM band, not only
in the portion of the band dedicated for noncommercial public radio use, and
will be assigned frequency allocations separated from existing stations by at
least two channels (first and second adjacent channels).
You Put Your Antenna?
This is the most important part of Section V, because it will
determine if your proposed station can be awarded a frequency on the FM dial.
FM signals travel in line-of-sight, which means that the
higher the antenna is off the ground, the further the signal will travel.
Any physical obstruction in its way will stop the signal. FM antennas are
relatively small and light-weight, and can easily be attached to a wide variety
of supporting structures without any special reinforcement, such as telephone
poles, metal or wooden masts, water towers, elevated roof-top structures, and
existing towers. So be flexible in looking for a good location. The FCC requires
that your antenna be located within 10 miles of your offices or campus.
Try to find the highest location possible for your antenna,
such as a spot above other buildings, on top of a hill, or some other place
where the signal will not readily hit a geographic feature or large solid
object. This might be a pole on the roof of your own building, the roof of a
higher building nearby, or some other tall structure in the vicinity. You can
also use an existing tower, either one on a roof top, or freestanding on the
LPFM antennas are small and lightweight,
much like a TV antenna that one puts on a roof to improve reception. They do not
need a large supporting structure or special reinforcement to hold them up, and
they will have little wind load. You can mount them on a mast or something
similar to get elevation.
If you do not own or control the location where you want to
mount the antenna, offer to put up a pole or small tower to elevate your
antenna. In some cases, you should be prepared to offer compensation or pay
Along with the antenna site, you must secure a place nearby
for your transmitter. A 100 watt FM transmitter is not
very large or heavy - the box is roughly the size of a desk top computer. It can
sit on a shelf or table, or be installed in a rack. The location must have
electricity, but does not demand any special power requirements, and it must be
inside protected from the weather. Be prepared to pay the electric bill.
Finding your Antenna
Coordinates and Broadcast Channel
You will need to
contact LPFMRadio.com in order to accomplish these most difficult feats. Yes,
you are supposed to be able to do this on your own but, it has been our
experience that, of the few who do manage to get a viable application on file,
very few work as well as expected and, of those few, even fewer are ever
actually constructed simply because the applicant usually makes some fatal flaws
within the application and cannot correct them. You get ONE CHANCE at getting
this right. Is it really worth risking the future of your radio station to save
a few dollars at this point?
If there is a frequency
available at your proposed antenna location-congratulations!
Now, LPFMRadio.com can get to work preparing an application to be submitted on
your behalf when the FCC opens a filing window!
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