- November 14, 2005 at 3:09 am #6449RayParticipant
Total posts : 1
Need help for Live Nativity and radio
I am looking for lots of help. I have spent the past 5 hours looking at how my church can broadcast information to visitors that drive through our parking lot to view a live nativity scene. I llearned almost nothing other than its a lot more complex than I thought.
I envision broadcasting a gospel message, a description of the sights, some safety points and a salvation message to the visitors. We expect at least 1000 cars over two nights. Each visitor drives through our lot to view the scene.
Our driveway and lawn is about 200 feet and cars get backed up about 1/4 mile at the peak. I understand that the max coverage w/o a license is about 200 feet.
I have many questions. We would be broadcasting for a few hours on two days so obviously cost needs to be minimum. I don’t think any members have radio experience so we have to have minimal set up requirements.
Do we use FM, AM?
Do we have antenna near road to get farther coverage?
Do we use CD and have everything recorded or do we also have live mike?
Do we borrow equipment from someone ? Who would be likely to have it? I wondered about realtors. Any other thoughts?
What equipment do you suggest?
All comments will be helpful, thanks in advance.November 14, 2005 at 5:44 am #12779jbprptcoGuest
Total posts : 45366
I’ll jump in here where angels fear to tread, sort of the blind leading the blind. Given your short time to do it and a non technical staff, I think you hit the nail on the head if you can find a realitor in your area who has one of the packaged AM transmitters used by them on a single property to sell that property. FM broadcasting is legally limited to a short distance as you’ve found out. AM allows more leeway in that you’re limited by the amount of power and length of the antenna and not the distance you can transmit. The maximum antenna length legally on AM is just under 10 ft, the power 1/10 of a watt. Now you don’t have to remember these figures if you can borrow a unit from a realitor, just wanted to clear up your idea of stringing a long antenna. Your reaching a quarter of a mile is somewhat impractical with one of these units, however the realitor’s units usually have within some recording device upon which to record your message so that would simplify things, and I believe they have a 10 ft wire antenna with which you can experiment, ie, various placements of the transmitter and wire for maximum range. Those of us who get into this hobby of low power AM broadcasting and work for a mile or two of range spend much time building somewhat complicated antennas and wiring transmitter kits. JimBNovember 15, 2005 at 9:43 am #12780radio8zGuest
Total posts : 45366
Just want to add a little to what has been said. You mentioned that your goal is to cover a parking lot.
I think you should look at a Part 15 FM transmitter. There are kits available for about $100. If you already have the audio source it is just a matter of plugging the audio in and you’re on the air. Check out other posts here or Google it. I don’t know of any assembled units, so if you go with a kit, you will have to find someone to complete the assembly for you. If your congregation has no one who can do this, contact a local amateur radio club. Maybe someone there can help you.
The suggestion about AM is good, but AM requires careful consideration of the antenna to get a decent range. The cost for an AM kit and an FM kit are similar and for what you described, I would go FM.
Hope this helps.November 15, 2005 at 10:17 am #12781radio8zGuest
Total posts : 45366
Hello again Ray,
I just reread your post and I realized that I didn’t address all you questions.
Regarding the program source, there are two levels to consider. One is what is called “line level”. This is what you get out of a CD player or computer or stereo line output system. The other is a “mic level” which is what comes out of a microphone. All the transmitters I know of use the line level which is much more voltage than a mic level. So, if you need to use a microphone, you will need a microphone preamplifier to convert the mic level to the line level. Many folks use a mixer which accepts both signals and sends the output at line level to a transmitter.
You are correct that the usual FM part15 range is about 200 feet, but car radios are very sensitive. I have a part 15 FM transmitter and using a 19 inch antenna in my basement, I can hear my signal about .2 miles distant.
I am afraid that the only way that you are going to know what range you can get is by trying it. Some claim more than I and some claim less.
If what I wrote sounds complicated, that is because it is, but it can be done. Once you get your program to the line level, transmitting it is easy.November 18, 2005 at 4:12 am #12782EbachervilleGuest
Total posts : 45366
Part 15 FM should cover your parking lot, there are broadcasters at burning man type events that use the legal watage and use a nice antenna and they get over your 200 foot mark with no problem..
If you whant to cover all the area including the cars lined up on the road.. I would go AM.. and you will probably need to build a antenna ect.. or buy one from antenna guy…
All in all your looking at anywhere from 400 to 800 dollars.. and some assembly…
Now if you have the cash look at the rangmaster units.. $1000 and a antenna mast from radio shac and your set.. I would think of this as a project that would be used more than once a year consider broadcasting in AM all year round. Consider it a way to increase your organizations congrigation.. people that may not go to church but live in a mle or so can tune into the sermons by radio.
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