I have posted this on another forum, but wanted to try here as well. I have a problem with an FM Transmitter at a baseball stadium. It is a Ramsey FM 30 and I am using it to broadcast in the stadium, the feed going out over the internet. My problem is that it is a large facility for high school. Seats about 1500, it it has aluminum bleachers. The bleachers are covered and it is an alumunum or metal roof of some type. The press box is skinned in an aluminum or metal siding as well. In the press box, I can hear the transmission great. (the transmitter is located in the same room). If I step out of the press box, nothing but static. I moved the transmitter outside the press box, nothing but static. Any suggestions? My guess is that all of the metal is causing me issues.
I have posted this on another forum, but wanted to try here as well. I have a problem with an FM Transmitter at a baseball stadium. It is a Ramsey FM 30 and I am using it to broadcast in the stadium, the feed going out over the internet. My problem is that it is a large facility for high school. Seats about 1500, it it has aluminum bleachers. The bleachers are covered and it is an alumunum or metal roof of some type. The press box is skinned in an aluminum or metal siding as well. In the press box, I can hear the transmission great. (the transmitter is located in the same room). If I step out of the press box, nothing but static. I moved the transmitter outside the press box, nothing but static. Any suggestions? My guess is that all of the metal is causing me issues.
Terry
What kind of antenna are you using? I can't imagine the metal having a negative effect if your antenna is outside. If you know your transmitter is working I would attach an easy-to-assemble quarter wave ground antenna to your transmitter and put the antenna on top of the press box.
Using the whip antenna included with the transmitter. I am thinking the same thing that a better antenna would help get the coverage I need.
Metal objects within a wavelength or two of the antenna could be reflecting your signal away from your audience, or otherwise creating tuning or matching problems. The structure shouldn't present a problem in general, but nearby metal objects might inadvertantly form an undesirable antennal element. At 100 MHz, a wavelength is approximately 10 feet long (9.84 something, to be exact: 11811/F(MHz) = wavelength in inches).
The point is that anything metal that is 1/4 wavelength (2.46 feet) 1/2 wavelength (around 5 feet) 5/8 wavelength (6.15 feet) one wavelength (9.84 feet) or any combination of these, is going to interact with your antenna in what will likely be an undesirable way.
Others might have more exact information, but off hand I'd say you're going to want to locate your antenna 35 to 50 feet away from any portion of the metal structure in order to be certain you're free of parasitic influences. This might mean locating your transmitter and antenna high and in the clear, and then running audio and power out to the transmitter via a long cable.
I have a FM-30B and have no problem getting several city blocks at "full" power (~35 milliwatts). It occurs to me you may not have gone through the setup menu and check all the setup parameters. If you have, now might be the time to recheck them.
Also, if the transmitter was left on for any extended period of time without an antenna the output semiconductor could have fried. GAL5's are known for their ability to take alot of abuse.
Also, go back to the manual and notice the suggested length for the antenna at a specific frequency. You can adjust the length of the "rat-tail" bnc connector antenna to be closer to the appropriate length.
And finally, make sure there isn't another signal on the air competing with the frequency you are trying to use. If a FM translator in the vicinity would be within the second adjacent channel, it could desense the front end of the receivers in the stadium.
Just some things to consider.
Marshall Johnson, Sr.
Rhema Radio - The Word In Worship
http://www.rhemaradio.org
It's really important to remember that most of the low power FM transmitters we use have often have less than ideal buffer amp sections to keep costs down. That means that the setup routine should usually be revisited each time you move, change or reset just about anything 🙂