-3dB Gain is NOT bad, here is why...
Posted: 06/06/2017
Many customers are afraid to buy an FM antenna that has a negative gain. They seem to feel that they are losing power. Nothing could be further from the truth! In this article, I will use our PCP1 circularly polarized FM antenna as an example. The PCP1 has an antenna gain of -3dB. So that means that you are losing half of your power, right? This is not a true statement, here's why... When the gain of an antenna is measured, it is only measured in one polarization plane, not both. What this means is that the gain is only measured in either the vertical OR horizontal plane. The PCP1 is a circularly polarized antenna, so there are both vertical and horizontal elements on the antenna, consequently, there are both vertical and horizontal components to the signal radiating from the antenna. In true circular polarization, half of your signal is in the vertical plane while the other half is in the horizontal plane. So 50% of your power is in the vertical plane and 50% of your power is in the horizontal plane. ALL OF YOUR POWER (100%) IS STILL THERE! You don't lose anything! When looking at the gain figure for ANY antenna, we have to remember that there is no magic effect that the antenna can have to either amplify or destroy your RF power. It's simply a matter of how the power is distributed or radiated from the antenna. Likewise, when an antenna has a positive gain of +3dB, your power is not really doubled. Rather the antenna is simply re-distributing power from one area and placing it in another giving the illusion of increased power. Let's look at it this way; imagine if you had a special pair of glasses that would allow you to "see" RF power coming off of your antenna. If you stood back far enough away from your antenna, and your antenna had a power gain of 0dB (meaning it had no gain or loss) the signal would be round, like the shape of a huge beach ball. Now let's say that we add +3dB gain to the same antenna, it would be like you took your hands and put one on top of the beach ball and the other on the bottom of the beach ball and applied a little pressure. The ball would be "squashed" a little bit so that it would be flatter on the top and bottom, but the outer edge of the ball would "bulge" out and become larger. In this same way, an antenna with gain "pushes" the signal out around the outer edge while pulling it in from the top and bottom. No extra power is created. Rather the exact same amount of power is coming off of the antenna, but being distributed differently. This is why having a circular antenna such as the PCP1 is actually better than having a vertical only antenna that has a positive gain. The reason for this is because the listener's receiving antenna can come in all shapes and sizes (vertical and/or horizontal types). When you are broadcasting on FM, it is best to send your signal using an antenna that has the same format or polarization as the listener's receiving antenna. Since receiving antennas are available in vertical (like a stick antenna on older automobiles) or horizontal (like the 300-ohm twin-lead antennas on most home stereo systems and/or window antennas on cars), it is best to transmit in circular polarization (both horizontal and vertical polarization). In this way, the broadcaster has both bases covered when it comes to matching up his transmit signal with that of his potential listener. This is why almost ALL professional FM broadcast stations are using an antenna with circular polarization and not vertical only polarization. Since the FCC only measures the power in one plane (vertical or horizontal) you are able to actually put twice as much power into a circular antenna (such as our PCP or CIRPA antenna) than you can put into a vertical only antenna. By putting twice the power into the antenna, you are effectively putting twice the power into the air, which gives you much better coverage than any "vertical only" antenna could ever provide. |
Posted: 08/17/2017
If you own a BW Broadcast original TX series FM Transmitter or V2 FM transmitter and need to have it repaired, Progressive Concepts can repair it for you.
Simply call Progressive Concepts to obtain an RMA number. It's that easy!
Once we...
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Posted: 06/06/2017
We are often asked "How far will my 100 watt transmitter go?".
This question does not have a simple answer. WHY? Because there are so many factors that will determine how far your transmitter will go that there is no single answer to...
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Posted: 06/06/2017
Overtime, pressure grew for a solution to allow community organizations the power to broadcast their message locally over the radio. As a result, the FCC began granting licenses to non-profit organizations that allows them the right to broadcast FM...
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Posted: 06/06/2017
Periodically, the FCC opens the door for new applicants to take a shot at getting a license to run their own station. These applications are only available for non-profit and community organizations. For more detailed information on when and how you...
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Posted: 06/06/2017
FCC licenses for LPFM stations are only granted for “non-commercial-educational” use. This means that although you can’t sell advertising airtime directly, you can accept contributions from businesses and incorporate their name...
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Posted: 06/06/2017
If you’ve already reviewed the application process, your next step would be fundraising. Fundraising is a great way to gauge community interest and spread the word about the future of your station. Not to mention, it’s essential for...
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Posted: 06/06/2017
The leading one-stop resource for obtaining equipment, as well as assistance with setting up a professional broadcasting studio, is Progressive Concepts. Progressive Concepts offers complete equipment packages containing everything you need to start...
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Posted: 03/29/2017
The Numark MP103USB CD Player is perfect for use in Radio Broadcasting. The MP103USB has all the features needed by todays demanding radio DJ's. Furthermore, the MP103USB is rugged in design so that it lasts under the rigors of constant use.
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Posted: 08/11/2016
Formula to figure ERP of an FM Antenna
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Posted: 09/28/2015
Those who have an interest in operating a low power FM or LPFM radio station, either on behalf of a company, institution, or for personal use, are often intimidated by the prospect of assembling all of the necessary equipment and sending sound...
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Posted: 08/27/2015
Whether you are a radio broadcasting hobbyist, or a full time disc jockey/talk show host, nothing is more crucial than your radio transmitter. Other components found within this industry such an amplifier, oscillator, modulator, power supply,...
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Posted: 07/21/2015
If you’re like many people, when you think of the difference between AM and FM radio, you might say, “Well, AM is mostly talk radio and FM is mostly music.” While this is somewhat true (there are exceptions with both),...
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Posted: 05/15/2015
Imagine being able to send out music and thoughts through energy, electrons and radio waves. An FM antenna does just that. Antennas are sometimes called an aerial. You see antennas every single day of your life. They are built into our cell...
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Posted: 04/08/2015
Why would someone want to host their own LPFM or low power FM radio show? The answer is simple. Hosting an LPFM low power radio show is a wonderful way to promote a business, a cause, or to inform those in your community about a...
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Posted: 03/16/2015
Emergency Messaging systems were once very expensive, but they have become much more affordable in recent years. They offer many benefits to radio stations, and now, more than ever, DASDEC systems are affordable for even the smallest radio...
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Posted: 02/19/2015
Every sound engineer has had to deal with telephone lines at one time or another. Linking the phone conversation to an audio system when taking calls at a radio studio can be accomplished via telephone hybrids such as the JK Audio AutoHybrid....
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Posted: 01/20/2015
In previous posts, we’ve outlined the equipment you need to get your low power FM radio station up and running. But before you start purchasing the different pieces of your broadcast puzzle, you should first understand the function of each...
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Posted: 12/22/2014
After you’ve assembled the necessary equipment to broadcast your signal through the airwaves, you can begin to pick and choose certain items that will enhance your broadcast. The most important component to ensure that your voice carries well...
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Posted: 11/20/2014
Out of all the equipment needed for radio broadcasting, there is no piece more important than the FM radio broadcast transmitter or FM Transmitter. Sure, the microphone picks up your voice, the audio processor makes it sound better, and the...
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Posted: 10/21/2014
So you’ve been dreaming about running your own radio station, and you have a good idea of what you will broadcast, but how do you know exactly what equipment you’ll need? While there are endless bells and whistles you can purchase...
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Posted: 10/08/2014
Are you passionate about radio and dream of one day running your own station? Well, your dream is not a distant reality. There are a lot of resources available to help you get started, and the equipment required is more accessible than...
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