The other thing to consider is that while a Talking House, as an example, may have a range of 1/2 mile or more, that would be only if you were listening on a car radio, which is very sensitive. If you're going to be listening on a portable or hand held radio, range will generally be much less, as they're designed to listen to only the strongest stations - in fact, I've generally found that the biggest problem with those cheap receivers is signal bleedover from the strong stations, completely obliterating the weak Part 15 signal beside them (these radios tend to have very poor selectivity).
That's why it will be very important to get the transmitter, with its antenna, up as high as possible to reduce obstructions to the signal. If you can place the transmitter antenna out in the open on the parade route, so much the better. Finally, pick a frequency, if you can, which is well away from any strong stations in your area (and as RFB suggested, pick a frequency that is high, again if possible, but below 1610Khz).
Range is almost always determined by the quality of the listening receiver, and I suspect that most people will listen with low quality radios.
Wow! Great suggestions. Thanks to all. I don't think bleedover will be much of a problem. The nearest radio station is 50 miles, then 100 mi. then 150 and so on. And I think for the most part those are FM.
I'll present the ideas you've given here at our next meeting. I'm pretty sure we'll go with the talking house option for this year. I can present the options for upgraded systems and if there's somebody with the expertise to run with it, let 'em run. Possibly a student at the high school might like to give it a go.
I know I'll be busy cookin beans and washing dishes for this event. My wife and I just completed an EMT course for our volunteer fire and rescue unit over in Portal, AZ which is across the valley. Rodeo has it's own fire dept. but ambulance is out of Portal. So, personally I'm getting overextended to take on too many more projects. Hopefully I can get the ball rolling on the suggestions you guys have offered and someone will step forward to carry it forward.
I'm going to post some links to local blogs with lots of photos. Some will have photos of yesterdays St. Paddy's parade in Portal, AZ. If you want to poke around you can find photos of last years 4th of July. The first link is an awesome site, from Bruce Thompson. He's a geoligist/photographer/ultralight pilot and his site is endless I think. Enjoy, Joe
http://bloggingfromthebootheel.blogspot.com/
http://www.portalrodeo.com/
http://chiricahuaskyislandrodeo.blogspot.com/
I use a Talking House V5. I can't speak for others, but I know I got a good one. I also have another one ... I put the 10' wire antenna on it and stuffed it into the crack on the inside of an upstairs arched window, so half the antenna curves in a semi-circle. With the rest of the house more or less in the way, I could still hear it with good clarity 300 yards away, mostly down hill ... if that helps ... YMMV.
Remember, AM radio reception can have interference from a variety of sources, but it should still work for your purposes. Even a good portable radio, like a Sangean or a Sony 7600 should also work.
For my $$ the TH is a heckuvva good deal in a Certified Part 15 transmitter.
Thanks Ken,
Appreciate the input. I think we'll give it a go.
Joe
Hi Joe,
You say you need a transmitter for July 4th and only have a $100 budget? Well http://www.talkinghouse.com has a sale going on right now for $95 bucks! Check it out. Failing that I'm sure you have some Realtor buddies in town who are equally interested in helping out for your 4th of July parade. They can also get some free advertising. Ask them can you borrow a TALKING HOUSE transmitter for the event (they probably have a few in stock). Tell them you'll take good care of it and allow them to put a small blurb at the end of the loop about their Realty business. The Realtor knows how to hook it up too. The instructions are on the website and its very plug-n-play.
SpookySr
Hi Joe,
Here is another idea which is cheaper: 
Notice you will need the TriSquare FHSS (frequency hopping spread spectrum) walkie-talkies (W/T). They are highly secure and use digital audio. No one can hi-jack, interfere, jam, or even receive these units. You will hold one for your master feed. The others are plugged into locked-on PA systems or megaphones placed along the route in buildings, homes, or telephone poles. They may need a person to watch over each one (i.e. prevent theft, tampering, replace batteries, adjust sound, etc).
They can be placed several thousands of feet along route. You may only need 2-or-3 units to have 100% coverage. You may already have PAs, bull-horns, guitar amps, etc. The W/T's only cost $18 bucks without recharging unit on http://Amazon.com. You can just use 4 AA alkaline batteries.
You will need to go to Radio Shack to get an adapter cable from sub-miniature plug for the W/T to miniature or headphone plug into the amplifier. You'll need someone to adjust placement of units to avoid echo effect that PA systems cause against buildings, walls, and street surface. Makes it harder for people to understand what's being said with too many echoes. You can speak to them through the system during setup (i.e. "OK Harry a little more to the left...").
SpookySR
"They can be placed several thousands of feet along route."
Great alternative idea Spooky. Problem is however, several thousand feet along the route would take you WELL outside of the community boundaries in both directions!
Might want to take a look at google maps for Rodeo New Mexico. With that small size, a single TH unit would cover the entire community if put right in the center!
Having radios and amps and speakers along the route would be no different from running wires to speakers along that same route, things could get damaged, stolen, or someone not paying attention walk right into one or under one or over one and hurt themselves and bada bing...lawsuit.
If someone breaks a nail trying to tune their radio to the parade signal, the worst to happen there is a little bit of cursing at their own radio and no one is liable.
Besides that...have you any IDEA how hot it gets in southern New Mexico in July??!!! Heh....1.5 volt batteries would flake out in 5 minutes in that heat down there..not to mention warp those nice little plastic cases on those radios! Ahh..put them all under those little umbrellas to shade them..till someone decides to pluck one cuz it's cute and no one is looking.
Too much risk I think with scattering speakers and wires and amps and such. If your gonna go that far, might as well put a permanent setup of outdoor speaker horns that sound tinny and pierce the hearing and create sound wave echos bouncing off the buildings etc. There will always be someone or someone's next to one of those speaker horns and they won't appreciate they can't turn down the volume because it's blaring directly at their heads!
With the TH transmitter approach, everyone has control of the volume, everyone will get a much warmer smoother and more natural sound, and no potential liability to the community, parade organizers or anyone else.
RFB
"Our little parade and pulled pork dinner & dance afterward are our fundraising event that supports the community center and a scholarship fund for local graduates."
Sounds like a great time for all! I miss those large cook outs and gatherings. Nothing like that here except the small BBQ's at the park no one uses except the birds!
It would be a long drive from Casper Wy. to Rodeo NM., but never say never...there is still a plan to go visit family this summer in Alamo and the trip is planned around the end of June anyway...could make a quick side trip and see how things are going..maybe help a little if needed. If things look good for that, keep tabs on your thread here and I will let you know if I will be in that area on the 4th!
RFB
Once the transmitter is in place and the announcer turns on the mic to cover the parade, we are now talking about "producing the program" that people will hear over their radios.
The people attending the parade along the route will already be able to hear the portion of the parade nearest to them, so the radio will need to deliver a "bonus" or "additional" feature on top of the parade.
I suggest, for one idea, calling people up to the mic and talking to them so they will be "on the radio." That will make the broadcast an event in itself, added to the fun of the parade. People will be watching the parade on one hand and trying to find "the guy with the mic" so they can be "on the air."
Some people listening on the radio might get too close and cause squealing feedback, so be ready to remind people to "turn the radio down".
All this should be recorded onto a harddrive so that recordings of "The Parade" can be downloaded and enjoyed by the people in the future.
Thanks Fellas,
Appreciate all the help and suggestions. In the interest of keeping it simple and as low tech as possible, I'm still with the Talking House unit. We do usually have an announcer that introduces the next entry, grand marshall, etc. And in years past, if you were within 50 ft. of the announcer you could actually hear him. Since most everybody drives their AM receiver to the parade and parks it along the parade route, this year they will be able to hear what's going on down the line and join in with the playing of the National Anthem. I like this easy solution.
It does get a little warm here. Usually pushing 100 around that time, but if you can find a shady spot, 100 is nice! Unfortunately, there aren't many shady spots. And 100 degrees in the blazing sun should be kept to a minimum.
RFB, come on down. It really is a special celebration for this little community. And you described it perfectly. By 9:00 the dance is goin full bore, so bring your boot scootin boogey. The more the merrier and we can use all the help we can get!
Correction: I said pulled pork earlier. That was wrong. This is beef country, we cook it in the ground overnight and we pull it like pork the next morning.
Thanks again, Joe
Hey All, I got the TH5 and gave it the preliminary test. It works. I ran another little test the other day hooked up to our little PA and CD player and had limited success. We have a litte Realistic (Radio Shack) 40W PA. It has a line in connection for the CD player but no line out other than a headphone jack for monitoring the mix and output. With a phono-1/8" I get nothing, it cuts out the signal going to the TH5. So I tried headphones with a stereo phono jack and the headphones worked fine. So, I tried a stereo phono jack-1/8" stereo jack and that still cut out the signal to the TH5, but when I pulled the phono jack part way out, I got a pretty good transmission to my truck radio, a little fuzzy/distorted but hopefully that can be cleaned up. So, I'm guessing all I need for the TH5 is an unpowered signal out from the PA, which I don't have and the headphone out is a powered signal that kinda/sorta works when I pull that stereo phono jack part way out. Any suggestions how I can utilize that headphone jack as my line out to the TH5? I'll be setting up for real at next month's organizng meeting to give everybody involved a demonstration. I think I'll use an 8' or 10' step ladder with the TH5 unit near the top, then strap a pole to the side of the ladder so that I can extend the antenna another 10' above the ladder which should give me 15 to 20' of height for the antenna. I'm including a link to the owner's manual for the PA, and I just noticed there's a mix/bus connection on the back which might be the unpowered connection I'm looking for. Although, reading the instructions for how to use that connection, I'm not sure that would work either. Oh well, if at first you don't succeed........... http://support.radioshack.com/support_audio/doc73/73142.pdf Thanks for the help fellas. Joe
Sounds like the TH jack is mono (I believe it is), and you're using a stereo plug. Try getting a stereo to mono adapter.
The TH/iAM audio input must take a line level signal as it has a pre amp internally (agc). It also does not react too well to stereo plugs even though the input is a 1/8 stereo jack.
Plugging in a source such as an iPod player or other isolated audio source let's the input jack work correctly. But when tying in from audio sources with a common ground, the audio either mutes or is distorted. The solution for that is to use a 1:1 isolation transformer, or a ground loop isolator, either of which can be obtained from radio shack. The ground loop isolator is best as there is no need to assemble, just plug and play.
Put the ground loop isolator between the mix buss output of the PA and the input of the TH. Should be fine.
RFB
"The THite>/iAM audio input must take a line level signal as it has a pre amp internally (agc). It also does not react too well to stereo plugs even though the input is a 1/8 stereo jack."
?? ... I've never encountered this problem from a computer, neither desktop nor laptop using a PS-Charger, on two separate TH5's
Ya must've got hold of a bad unit.
"I've never encountered this problem from a computer, neither desktop nor laptop using a PS-Charger, on two separate TH5's"
Actually the unit I got was brand new fresh out of the box. What happens is using isolated sources, such as that of an iPod or laptop or desktop, the stock audio input will work fine, however try to connect up a mixer console or connect an output from a processor and that audio will either hum like a bucker or null out a lot of the audio going in, exactly what the OP is experiencing.
It is the way the input plug is configured. It is not a standard stereo 1/8 mini port, though it can be, but that is determined by how the jack is connected itself along with it's internal blade switch configuration.
I studied the foil pattern on the TH and iAM units at the input jack and it appears that when a stereo plug is put into it, one of the channels is shunted out completely (ring) right to ground (sleve) and the other (tip) is left alone. Now when a mono 1/8 mini plug is used, everything is fine because the mic plug is a mono 1/8 mini plug and does not have the 2nd channel (ring) to get shorted out.
Since iPods and laptops and even desktop computers have isolated in's and out's usually plugging in these things doesn't affect the input, however your still loosing one channel due to the jack's "jacked up" way of being configured and mounted and soldered on the unit's board.
That's why most have simply bypassed that nonsense and take direct unbalanced audio into the primary audio input to the modulator's op amp.
This is easily done. Looking inside, right next to the already installed audio input jack is a blank space on the PC board where a standard mono plug goes. Drill a hole for a chassis mount plug like an RCA or mono 1/8 jack. Connect it to the solder pads and then un-plug the 3 wire plug leading from the input selector switch on the back of the unit to the PC board. You now will have direct audio going to the modulator op amp and even the internal monitor speaker and volume control will still function as the other half of the op amp used to modulate the finals is also the same amp that drives the internal monitor speaker.
Enjoy!
RFB