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Rolling Your Own Wireless Communications System?
nuggetman asks: "My high school, like most others, has a theater program. One critical element of the show is the tech crew - the group of people behind the scenes who keep it all running. Communication between the stage manager (myself) and crew members (as well as between crew members) is critical. For this job right now, we're using standard hand-held walkie-talkies. They get the job done, but they're susceptible to dead batteries, incompatibility between VOX headsets, and interference from janitors, the office, hall monitors, and even the local McDonald's. We've been wanting to invest in a theater-communication system, but they can run extremely expensive. Is there any hardware out there that could use a standard PC (Linux or Windows) and some wireless headsets to roll your own communication system that could cover a long enough range (say the theater which is the size of a gym plus a decent range outside it) at a low enough cost? Our school just installed 802.11b/g throughout the hallways, so we could tap into that if necessary and add our own router near the stage if we had to."
1) Set up a private Counter Strike Server somewhere on the school LAN.
2) Get a laptop (with an 802.11g card in it, of course) and backpack for each crewmember.
3) Every crew member joins the game on their laptop, sets the laptop to never suspend, throws it in their backpack, and uses headsets to communicate with their team members!
Other than the sound of an explosion every three minutes or so, and the occasional "Terrorists Win!" all your communications problems are solved!
libertarianswag.com
Use yelling. Everyone comes equiped with all the right hardware. No sweat.
... which was admittedly about 18 years ago, we were happy to have the very latest technology... microphones and headphones (well, it was on a school-sized budget :-)
To be honest, I'd be surprised if WiFi would help you very much - it'd have to be a VoIP network, which isn't an obvious use of WiFi (the range is too short - most people would simply shout!)
Bluetooth might be an option, but they're basically clever walkie-talkies. Buy some rechargeable batteries and carry them. Sometimes the "clever" solution is the low-tech one...
Simon.
Physicists get Hadrons!
Some of my friends and I make up the A/V crew at my school, and I came up with an ingenious solution yet to be implemented: a zipline. The A/V booth is about 20 feet higher than the stage and a good 75 feet away, and we decided that a zipline would be the best way to get down to the stage to tell somebody something important.
I guess if you need to tell somebody something who's level with you then you'd have to invest in some model rocket engines or something.
The Human Cow - bringing you scrumtrelescence since 1995
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I'm sure there are probably a lot of problems with interference, but shouldn't it be possible to just get better walkie-talkies? Computers have their own problems too, and I'd imagine that any device you are using to communicate will have dead battery problems (unless you want to have 20 ft cords running all over the place).
Makes you wonder how in the hell Shakespear ever got by without a Slashdot subscription.
Sheesh. It's high school, dude.
"If you want to improve, be content to be thought foolish and stupid." - Epictetus
And you can build a great communication system. It's easy to do, even my 5 year old nephew can do it.
a few pairs of decent quality digital walkie talkies (im assuming u are using analog at present) would probably be a simpler, if not cheaper solution in the long-run.
Sounds like a battery-management issue more than something requiring a complex software solution.
Linux: Free if your time is worthless.
Skype is still a free VOIP solution. I think the problem would most likely be wireless headsets with good enough range though... I hope this helps!
Just buy a few ClearCom headsets. If wireless costs too much for you, get the old-style models and some lengths of XLR cable. Why waste time with all this computer stuff? It just complicates things. Use the simplest solution.
Why not buy some new handheld walki-talkies that have built in encryption (digital), wouldn't that be cheaper/easier than any computer network?
All you need is some tin cans and some stri-
Wait, does string count as "wireless?"
aaah yes stage crew.. I remember when I did that for my high school. WE did the lights and sound for the plays. Our equipment was rather old and our intercom systems went out every now and then as well.... usually at key times in performances of course. Our intercoms were a headset type setup that was hard wired to the walls to a unit up in the booth. The ehadset connected to a little waist box as well with a call button and volume controls. Not sure on the model or brand but it was _mostly_ reliable. We always had problems with wireless mics as well... As for the headsets, there was a large box on stage... size of a golf cart approximatly... we called it the reactor. Anytime you'd go near it with a headset... bzzzzzzzzz you'd be cut off completely and the box would start buzzing almost. I probably have cancer or something now from being by it so much :o\
Even a stopped clock gives the right time twice a day.
I'm confused, what would the PC accomplish? You can't possibly consider trying to do a VOIP solution for a highschool theator. You may know how it works but when you graduate no one else will. Save the cash and buy clearcom or telex. They're really not that expensive once you consider just how long they last. I've seen clearcom systems that have been installed for atleast 15 years, and telex for even longer. Instead of posting this to slashdot, write up a proposal to send to your school board or even student council.
Ah, to be an audio/visual nerd again.
Research shows that 67% of those who use the term "research shows", are just making shit up.
No, this is just silly. A laptop is going to be far more expensive than some high-quality two-way radios from Motorola or the like. Even if you already had the laptop, there's nothing that allows you to easily tap into VOIP via independent headsets. I'm not sure why regular, quality two-way radios (at $40 for a pair with rechargeable batteries) isn't good enough for this simple application?
Get the commerical GRMS radios like that use at Target and Wal-Mart. You know the things you see the managers using.
Everyone is deriding the topic poster, but perhaps he's going to /. high school... It would be interesting to hear someone's cost effective solution for home brewed VOIP.
Part of the hardcore faithful who believed in Apple long before it was cool again to do so
Well it sounds to me like your just trying to transmit voices not anything that demands real high quality audio. Of course, you don't wanna mis-interpret someone. And you state that "they're susceptible to dead batteries" but obviously any wireless solution is going to be susceptable to running out of juice.
It would certainly be POSSIBLE to hook up some old cheap computers, stick them in the stage area, the lighting area, etc, and hook up some wireless headsets to them. Then just run some voice software like speak-freely (available for windows or unix) or something...
But i've just gotta say... I think this sounds a little too complicated if all you need to do is talk in the same building. Why not invest in some GOOD but inexpensive radios. There are tons of options out there.
replacing it with NEW Folger's Crystals! (lets see if they notice the difference)
Look what happened to the mars rover. Computer crash and communication is lost. Stick to walkie-talkies.
While you could probably roll your own system with a lot of work, you are better off going with a real Clearcom system for theater use. They do both wired (cheaper, but it's really all you need for high school) and wireless (quite expensive). eBay often has some used eqipment you can buy as well. These systems are what are actually used in the field, and in many schools as well and are quite less likely to fail than a home-grown solution (rebooting the communications computer in the middle of a show so the SM can talk to a board-op is a very very bad idea). It may seem easier to put together a free system than buying the Real Thing, but by the time you purchase wireless eqipment and setup a custom system you have spent more in time and money than you would with a real system.
$800 for a CS-222 ClearCom 2 Channel Main Station is a lot of money, so another thing you may want to try are Motorola TalkAbout radios with headsets (not in VOX mode though, you don't want that in a theatre since you want to avoid unintentional chatter on the comms system). They tend to have fairly good range in my experience and if you take the time to pick out clear channels there isn't an issue with interference).
Use the money and buy more rechargeable batteries for the Walkie Talkies. Using batteries as an excuse to go VoIP, which also uses batteries, doesn't make sense.
If interference is the real issue, look into low frequency radios with a 5 watt range.
Sounds like someone wants a project.
Convince a local cell provider to donate phones and air time.
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They Are Vermin Feeding On Each Other's Feces.
I Hate \.
"Sawbuck?" Was that the 1860's?
Your best bet for cost and effectiveness is to get nicer walkie-talkies. At $40/pair Motorola FRS/GMRS radios have 22 channels, and a 2-mile range, plus you can get headset/microphones to go with em. I own a couple pairs and they're durable as hell (you shouldn't drop them in a lake, but mine came back to life anyway) and have 12+ continuous hrs on a couple AAs. Plus now you can multichannel your crew - Ch 1 is Lights/sound Ch 2 is backstage crew.... ~J >-- I'm not a pessimist, I'm a realist. It's not my fault that life sucks so much. --
-- I'm not a pessimist, I'm a realist. It's not my fault that life sucks so much. --
You can find information on rolling your own wireless communications system here and here.
Note that the subject line wasn't "Good Info".
How does encryption solve any of the problems in this article?
I work with a lot of presentations and lectures and I'm dying to know if there is any consumer or prosumer level digital microphone systems out there? Everything that you can find both at cheap ass Radio Shack and even high end audio stores is varying degrees of wireless. 900Mhz or 2.4Ghz just like cordless phones. Some through the word "digital" around but are still susceptible to interference and static.
What I'm dreaming of is something that is purely digital, from the device the speaker wears all the way to the speaker. I envision something like a Bluetooth wireless microphone similar to the bluetooth headsets that some cellular phones use. This bluetooth microphone would relay to either a box in the speaker's pocket or inside the lecturn. This box would then use CAT-5 or 802.11 to transmit the stream as a WAV or MP3 so that it could be played on a SlimMP3 or Shuttle connected directly to the speaker system. In theory the speaker could roam freely and speak clearly and sound crystal clear.
Is there anythign like this? One place that I work for is about 100 feet from high power lines. The resulting RF interference renders even the most expensive $600-800 wireless microphone solutions worthless. Wired microphone even have a problem, even with grounding wires you still pick up pops clicks and hums over fifty feet.
So, how about it? There are plenty of devices that can take an audio stream off a network and output a sound wave? How about a device that can record the sound wave and output an audio stream?
FYI - consumer or prosumer means less than four digits...I'm sure studios and recording studios have plenty of expensive options available.
-JoeShmoe
.
-- I wonder which will go down in history as the bigger failure: the War on Drugs or the War on Filesharing
You're a high school kid with walkie-talkies that can be used in pranks on McDonalds customers, janitors, and hall monitors, and you want to get rid of them?
The U.S. education system must be going downhill fast.
For something this "critical", you need technology that won't fail, but will also work in the kind of vast distances you're talking about. I suggest tin cans and string. Of course, you'll have to make sure nobody in the audience brought scissors, but with all the hi-tech anit-terrorism stuff they throw in schools these days, surely nobody can get in with sharp objects.
Been there, both in HS and college. Is there a particular reason it has to be a wireless system? We used wired ClearCom systems at both. Sometimes the cord was anoying, but usually it was not a problem, and it eliminates the VOX, noise, dead spots, etc. problems. A quick search found thisc h has some packages by Production Intercom that arn't too bad price wise, and you can probably find used equipment out there for less (eBay had some real ClearCom gear last time I looked)
http://springtree.net/pi/econocom.html
whi
The problems you cite are universal for portable communications systems. Batteries going dead, bad headsets etc. The key is planning and maintenance. If it is critical to the show then make darn sure the batteries are charged before the show starts and if one doesn't last the entire show then dispose of it. (Nicads and nickel-metal hydride need to be disposed of properly, Radio Shack does this for free) Keep a couple of spare radios ready to go and charge some extra batteries as well.
The better route to go is to get a license for your own radio channel and use higher end radios like police and firemen do. Schools often have a business band license for buses or maintenance that you could use on the off hours, this keeps other people off your frequency. The radios cost more but you are paying for reliability.
Don't whine that you don't have the money, get a system designed by your local radio (Motorola) dealer and then start getting the money through grants and donations. I get solicited all the time for free stuff and sometimes the dealers can hook you up with a corporation that is changing systems out and looking for a place to donate the old (but good) equipment too.
The main thing is plan ahead, and plan for things not going perfectly.
Ok, i'll roll up the network in one, but I'm sure as hell not sparking it.
today is spelling optional day.
Seriously, you know NexTel lives for these kinds of situations. Get a bunch of NexTels with ample walkie-talkie minutes and then get some headsets. Put the phones on your belt and then either use voice activated talk mode, or the old push-button style. Frankly, I hate half-duplex stuff but it's what you are already used to. The advantage is that you can roam anywhere (not just the gym) and have instant communication. It shouldn't be all that pricey either. They have pay-as-you-go prepaid plans. The school could get a prepaid plan whenever there was a production and then when it was over, collect the phones and leave them in a drawer until they were needed.
Rather than NexTel, I would recommend getting Cingular or Verizon and then signing up for a plan with unlimited Mobile-to-Mobile minutes. Then get headset and now you have a full-duplex system. I don't know Verizon, but Cingular phones can conference up to six other lines, which is probably enough for a stage crew. And you can all hear and talk to each other. Not sure if there is a prepaid or pay-as-you-go option.
But anyway, look cellular. I think it's probably the best option for the money, no need to cobble something together that may not be reliable. Cell phone networks rarely go down...if your homebrew solution blows up on curtain night your ass is grass unless your solution also has an "understudy" ready to go.
-JoeShmoe
.
-- I wonder which will go down in history as the bigger failure: the War on Drugs or the War on Filesharing
You can use FRS frequencies with FCC-approved FRS walkie talkies.
/not/ license free.
To use any GMRS-exclusive frequencies, you MUST purchase a license from the FCC and use the appropriate call sign and operating procedures.
GMRS radios are
Jim
try teamspeak, it can be used instead of VoIP, and each team/crew can have their own private channel...
try it out: http://www.teamspeak.org
Investing forum
If by walkie talkies you mean the standard 49 mhz AM kind, I can understand why you have problems. Go with an FM UHF solution. It will be much clearer and you'll be able to communicate over longer distances.
To solve the interference problem you could use FRS or GMRS radios with CTCSS. As long as you pick a tone no one else in the area is using, you should not hear interference even from others using the same frequency.
If you go with GMRS, someone will have to get a GMRS license. This is easy to do (no test to take, just pay the FCC), and I think you only have to have one license for an organization. You can then set up a temporary GMRS repeater in your auditorium that will ensure everyone can communicate with everyone else. The advantage of GMRS is that it can use frequencies that your garden variety FRS walkie talkies can't use, so you will get less interference from kids, etc.
The only problems with the above are that if anyone wants to use the same channels and CTCSS encoding as you, there is nothing to stop them.
I'll bet there is more than one large church in your town, and each one has wireless gear that they use for services sunday morning, and no other time. Just talk to them in advance and borrow their gear. Most would be more than willing if you ask correctly. (and take care of the equipment)
Note that there is an art to asking. Best is to have someone in the production (actor, teacher, think outside of tech crew) ask. I'm not sure about much else because as a tech guy I don't know how to ask.
Basically, it mimics a standard phone line, and any telephone device you plug in can communicate with the others. You can run long cables and use splitters [nearly] to your heart's content. For about $30-$50 per station (hundreds less than a real, however superior, Clear-Com system), you can purchase corded or cordless headset telephones which work nearly as well.
If you do that, be sure to get phones with mute capability; and if you go cordless, be sure to check on battery life and try to get phones that don't beep too loudly. You might even need to disassemble the cordless phone and disable the internal beeper to make it silent.
Two things that are really nice about true Clear-Com systems is that (1) they can be operated silently (i.e., without beeping), and (2) their mute/talk controls can be operated by feel alone -- you don't need to look at a mute LED to determine whether or not you're muted. Those features are hard to come by on unmodified corded and cordless phones.
In general, a theater intercom system needs to be absolutely reliable, and should also be full-duplex (which walkie-talkies are not, but telephones are). I'd shy away from creating a custom wireless soultion with unproven technology -- it will take much more time to develop and won't be as reliable. If anything goes wrong during a show, or if reception isn't good enough, you've got big trouble.
get cellphones that have unlimited sprint to sprint calls. makes sure you get decent signal in the auditorium. get the smallest plan available in your area.
"Dogs and cats, living together...it's mass hysteria!"
Honestly, this is worse than a dupe.
In my experience all professional theaters use telex or clear com systems. Wired ones are quite expensive, and prefered as you can get headsets powered from the jack. However, both also make wireless systems that use FM and have quite good quality and range. The wireless systems are not nearly as cheap as walkie talkies, but they are far cheaper than wired systems and will last for years. It may be worth the time and effort to get some approved, or do a fund raiser.
Cisco sells wireless VoIP handsets.
First let me say that there's a lot of good ideas on here with alternative solutions, walkie talkies and whatnot. However, although it was almost a decade ago, I remember what it was like to be in technical theater. Specifically I remember it was great because as a sophomore I could frequently give backrubs to the hottest senior drama cuties. This provided a lot of opportunities for social development that would have been difficult to come by as a loner geek who spent the bulk of his social life on the other end of a 300 buad hayes smart modem (Yeah, I know only about ten years ago, but I was poor too).
:-)
So anyways rock on man.
Like I said before, I remember what it was like, and it wasn't just about getting the job done as simple as possible. Sometimes it was getting the job done in a really cool way, going over the top, and showing off. I mean, compared to the drama students on the stage, how often does the tech guy get to do that. The techie has a job that if they're doing it right they're not noticed at all. So I can understand your desire to go for the cool solution.
If I were you, and operating under the above assumptions, I would get my hands on a few IPAQs. They got some decent battery life, good integration with 802.11b, and if I remember properly usb so you can connect a handset. They're relativelylight weight, and you can get some older ones relatively cheap. We're probably talking a semster worth of bake sales, but hey, it's for a good cuase. Plus you can install an IM client on it to do text as well as voice for broadcast directives froma central source. You've got your choice of operating systems to run on it. So if I were you, and wanted cool geek look at what I can do points, that's what I would do.
Of course, also remember, you can go to any Fry's Electronics, or even Walgreens and pick up about 15 FRS radios that have a range of about a mile, and what 14 channels to choose from for less than 200 bucks. Not a whole lot can go wrong with them, and the tech ability to use them is negligable. I used to play with a live action gaming group (*cringe*) that made extensive use of them. It worked out pretty well, although you will run in to a lot of useless chatter. This solution would probably be just as cool and impressive. It also has the added bonus that people will want their own unit, so you only have to manage a deparmental pool of temp units for those who can't or won't get their own, plus the additional bennefit of probably creating a weird sort of wireless underground at your school.
But remember, don't forget to offer the backrubs
HaXXXor.com - Naked Chicks Teach You How To Ha
Old high school I went to (North Peace in Fort St John) had a moderately succesful theater going for a few years.
Took the profits from one of the tours and bought pro theater grade wireless. No idea where to find info on the system they used but it worked (and still works) for them.
Good luck! There's always a way...
The whole point of having -wireless- communication is so that you can have your people mobile, and still able to communicate. A wired system does you no good if you're on the grid 40' above the stage, and something breaks elsewhere. This, apparently, happens often.
The prevailing "standard" (if you want to call it that) is that ClearCom systems are used mainly in fixed locations, like your theater. Telex/RTS (my personal favorite) are used more in remote production trucks and broadcast facilities. I have always found that the RTS is the more versitle and adaptable of the two major players.
I would suggest that you check out each of these two websites and look at their lower-end products.
http://www.clearcom.com/ & http://www.telex.com/
They are still high-quality systems that will give you years of great service, but at a lower price than their full-blown premium systems. Once you find something that fits into your budget, check out eBay to see if they have any pieces, parts, or systems available.
There are also some great inexpensive no-brand-name systems available out there. You may want to check out Broadcasters General Store or Markertek to see what they may have. Their links are http://www.bgsfl.com/ and http://www.markertek.com/.
Good luck!
The number 1 problem of working in a cubicle - 23 power cords, 1 outlet...
CB Radio, used by walkie talkies, is a cheap and reliable system that should work well for this purpose. Depending on the actual devices used, you can get pretty good range. I had a 3-channel handheld unit 15 years ago that could easily transmit and receive for up to 5 miles.
I believe there are about 40 different CB channels that you can use. This would allow you to switch to a different channel if you get interference or pick up unwanted conversations on one particular channel. Some channels are reserved for certain uses (Channel 9 or 11 is emergency use only, Channel 14 is the one most commonly used for single-channel walkie talkies).
Browse through Radio Shack or some similar electronics store to find one with the features (# channels, range, size) you need. I doubt that the cost would be anywhere near as much as some of the previously mentioned higher-tech solutions.
Forget about Wifi PDAs. Since Wifi is an always-on data connection, it's inefficient with power. Battery life sucks and you can't get headsets for them. Most have headphone jacks but no microphone jacks.
Still, if you want to try it XTEN makes a SIP softphone for PocketPC. There's probably ones for Palm OS too.
Use cordless phones. My mother is a theater teacher and my dad runs tech. We use a pbx like unit that lets us connect many phones together and we use a mixture of corded and cordless phones to get the job done. It dosn't get much more inexpensive. Ohh and my advice... the computer stuff always gets banged up when other people use it.. so try to stay away from anything that breaks easy.
You're making this too damn complicated. I just bought walkie-talkies that have a 5 mile range, low power usage, and 24 different channels. They work great. Pick a channel that nobody else is using. Simple.
Don't buy anything. Work on sharing the football team's headsets. They probably have a bigger budget than your theatre department anyways. This should work out as long as you never have a performance during a game, which you should never do anyways!!
If they don't have one, perhaps its a good time to talk about splitting the cost of one.
I would have to say that your best option would be to invest in the system
Think about it
1) The computer crashes.
2) PortabilityWill you be able to use this everywhere? You probably aren't going to take computers with you if you travel for competitions, and if you do that takes up your setup time.
3) Lag, you need real time conferencing behind the stage and can't wait even for a second of lag time if something goes wrong.
4) InterferenceMost people in the audience probably have a cell phone which operates very close to the 802.11b standard of 2.4ghz. You would quite possibly lose signal in that event, and even if just for a momment, you would have to wait till it was over, reconnect the Wifi signal, and restart the voice program.
Wouldn't it suck if suddenly the system went down? You would have no time to troubleshoot. I was in my high school theatre team and we used a system from Telex. It was awesome. Didn't matter how much noise was around you cause you could hear the voices with no problem and no lag. Just flip on the power unit and plug in. Could even connect multiple units together for cases when you didn't want cables everywhere. We never had a single instance of failure. Do yourself a favor and buy a real system.
I actually really like the wired clear com. There are no batterys to buy, and no interfearance.
The audio quality is as good as anything out there, the system is full duplex, so you can talk over each other. It uses standard xlr cable, so if you have a house snake you can just run it along that.
Try to get a used system, the equipment lasts forever.
My only warning about clearcom is to make shure that you don't have any short's in you cables, they can bring down the whold system. Also be cautious running it along with electrical cables, they can induce hum.
We use clear com during all our major preformances. We back it up with gmrs, wihch is another option, think of gmrs as being super walike talkies, the big benifit of gmrs is that you are assigned your own channel by the fcc, and the range is a few miles.
The wired clear com is still the standard in the entertainment industry, gmrs is also popular for non preformance comunication, but almost evryone I know of uses wired clear com for preformance.
Get the most basic clear com unit you can find, and a few headsets, you can expand to more headsets when you need, they'll be available just about forever.
Well art is art isn't it, but then again water is water; and east is east; and west is west; and if you take cranberries
You should look into getting ham radio licenses for all your techs, and getting amateur radios. For non-commercial use (high school theater certainly qualifies), those would be perfect. The lowest level license is very easy to get -- simple exam, no morse code. You can buy a book ("Now You're Talking"), and if you read it, you'll ace the test. All the possible questions on the exam are also on-line (www.arrl.org). I cannot overemphasize how easy it is -- I learned what I needed for it in elementary school (higher-level exams are hard).
That gives you access to HF frequencies, which don't go very far, which for use in theatre is very good (no interference). To clarify, "not very far" means your town, as opposed to hitting stations in Australia and Japan. You may also be able to talk to the local ham community, and get a block of bandwidth for yourselves (there are protocols for doing this in the ham community, and it shouldn't be difficult). The FCC has laws about non-interference, and everyone on the waves is licensed, so you can expect people to respect this.
Using 802.11 would be both very expensive, unreliable, and cumbursome in comparison. Ham equipment will also last forever -- 802.11 already has a, b, and g, and will presumably have new standards coming out every so often. Every several years, all your equipment will become obsolete. There also aren't very well established standards for sending audio over TCP/IP. What you use now may not exist in a couple years.
SSB and FM, in contrast, have been here for close to a century, and aren't going away anytime soon.
You'll also have large numbers of potential suppliers for your equipment, open standards, and all that good stuff. This gives you access to amazing resources if you want to do anything more fancy (repeaters, etc.). You have access to a big block of bandiwidth, so you can switch channels if you want to have an individual conversation with someone. In addition, the equipment is general-purpose. You can use it for anything you'd use an amateur radio for, and other people's amateur radios can interface to you. You also have a very large community of technically inclined people on the waves who would be willing to support you (kinda like GNU/Linux, back in '94 or '95, before there was a mass of people). Hams are (a) friendly (b) helpful (c) constantly complaining about the lack of new blood. They also generally know a heck of a lot (the highest-level license basically requires you to know how to design a radio from scratch).
I cannot think of many other communications standards that offer all of this. To some extent, CB, but then you're vulnerable to pricks interfering on purpose (if your school is at all like mine was). Then again, if you're school is more civilized, or the dumb people are even dumber, this might not be a problem....
The only annoyance is that, when you transmit, you need to broadcast your callsign every so often (a series of up to 7 characters; for instance KB7DQQ).
I definitely wouldn't go for anything digital -- until the standards are better established, you'd find yourself with obsolete equipment very soon.
Having worked as a professional lighting designer/director for more than a decade (after starting in high school theatre) the answer is *NOT* to involve computers.
k scable.html~content )
For fixed positions, (left wing, right wing, green room, lighting sound booths etc.) use *WIRED ANALOG HEADSETS* like those from Chaos Audio (defunct I believe but still widely used) and Clear Comm.
Buy 'em used if you must but get proper a system but do NOT involve computers. You need this system to be reliable and simple. Lives are at stake. Yes really. As a stage hand you are the first line responders to real emergencies and theatrical events have a way of attracting real emergencies (venues that serve booze even more so).
General purpose computers *SUCK* for special purpose applications and suck and blow (at the same time!) for realtime special purpose applications.
(Credit is due for the homage made to: http://www.deadtroll.com/index2.html?/video/ossuc
1)DSP...first off, I can think of a few acronyms that fit, but I'm assuming you mean "digital signal processor" and I have no idea just what exactly you mean to do with one.
2)RF modulators? Like, uh, the things you use to plug RCA (composite) video+audio input to RF (coax, RG6) output? WTF?
3)12ga wire. Ok...I can see how this would have application in a communications system. Except of course for the fact that 12ga is FUCKING HUGE and that I have NEVER IN MY FUCKING LIFE seen anyone use anything bigger than about 20ga for communications purposes. Especially digital communications purposes.
Basically, I think you are full of shit. Really, really, really full of shit. Like, if you were a Native American, they would call you "Walking Eagle" because you are far too full of shit to fly. I mean, like, right before that guy comes in the truck to pump the shit out of the handi-jon...yeah, you're the handi-jon. Full to the brim. Of shit.
Obviously, you thought it would make you sound cool if you threw a couple of things that sort of sound like they might apply in a two sentence "look how smart I am cause I already did this" post. Of course, you ignored the fact that this system clearly needs to be wireless. And you ignored the golden rule of slashdot...somebody's almost always around with the bullshit detector.
Oh, and that 12ga wire thing. Heehee. Jackass.
But I'm really, really interested in hearing you prove me wrong. Preferably by explaining just how in the hell this collection of shit is expected to fulfill the stated goal.
Given a choice between free speech and free beer, most people will take the beer.
wifi is way too unreliable. if i were you i would not tap into that. it's a waste of time and money. get a wired, used headset system from ClearCom. tried and true method and used almost everywhere.
----
djzooky.com
I Like Cheese.
Way to feed the troll...
Jackass !
Im not here now... Im out KILLING pepperoni
Because the "parameter of the original question", while technically interesting perhaps, and geekily cool, would be the wrong solution for the problem.
A PC-based solution will cost more and be less flexible, and be more complex, than any simple FRS/GMRS/MURS solution. Not only will there be a very high technical support requirement (e.g., what happens when the PC croaks and you need to install the same software on a new one -- is the guy who designed it still available to help, and can the hardware do what it needs to?) but it will require custom hardware configurations and software. FRS/GMRS is a COTS (commercial off-the-shelf) solution. If you break one radio, you go to the local RS or online to Outpost.com, or any of a hundred other sites, and buy a replacement. Cheap.
Part of designing a system is to look at the problem, not just assume that the answer needs to be kewl and rad. Sometimes the right answer is the old, obsolete-looking one.
There are a few manufactueres of household cordless phones that allow phone to phone communication. Basically you can use the hand set as a walkie-talkie to communicate to any other handset that is one the same base.
SMS could be useful during a performence, and just having the crew on speed dial would be easy enough, the only problem i can see would be adressing all the techs at once.
"Sic Semper Tyrannosaurus Rex."
If you're already experiencing interference from the local McDs then it sounds like you're already using FRS radios, but did you realize they offer FRS radios with security channels? That should solve the interference problem.
Best part about FRS: they're extremely cheap. Walmart has several brands for less than $10 each.
If battery life is a problem I'd recommend getting FRS radios that use as many batteries as possible. 4 AA would obviously last the longest, with 3 AA followed by 4 AAA.
If that's not enough then get FRS radios that accept a power input, then get a compatible plug at Radio Shack and run a wire to a battery pack belt with enough D batteries to provide enough voltage. D batteries offer quadruple the power (mAh) of AA batteries, so you'll get tremendous battery life. 10 hrs from 4 AA? Try 2 days from 4 D.
I'd also recommend you contact the police and fire departments for suggestions. They're restricted to a budget (admittedly much larger) and usually get great rates on radios. Perhaps the school and join them in a group buy? Worst that can happen is they'll laugh and hang up, can't hurt to ask, right?
my karma will be here long after I'm gone
I don't have kids yet, but I'm sure when I tell them, "Back in my day, to get on the internet we had to use wires!" they won't believe me.
:)
As for 802.11... oh man I would have never passed highschool if I had a laptop and a wireless connection there... However I prob wouldn't have sluffed so much to go play L.O.R.D.
"When will this FP stuff stop?" "After the great growing..." "The great growing?" "Yea, when people grow up."
A cupple motorola P100's will work just fine, they put out 5 watts on high wich will go about one mile. Also they are capiable of running PL decode so you can eleminate interference on your channel.
You can pick them up for about 50 to 100 on ebay, or on rec.radio.swap, most of the time with a rapid charger, and a speaker mike. The standard battery is about 1100 mA/h which will last 8-10 hours fully charged. Sure they weigh about a pound, but you can throw them at the wall all day and they will still work! I have droped one from a 50 foot tower, and while the plastic case and battrey was broken, the radio still worked.
The only problem you may have is programing them, as you need a special cable called a RIB box to interface the computer with them. Polaris radio can set you up for about 100 bux, which is not all that bad.
I'm assuming that you people in the USA dont have a band allocated to the FRS?
Here in Canada, we have something called (you guessed it) FRS. Stands for Family Radio Service. The handsets run for around 25-40 bux canadian. You can usually get them in a pair for 50 dollars. They put out a half watt on vhf(get about a mile of range), and operate in a band allocated ONLY to the frs. There are..14 channels?
Hm, some quick googling turns up the fact that you DO have frs down there. Other than intermod, there isnt really much interference on the band. If you are using normal walkie-talkies, try some FRS radios. If the channel you are on has interference..switch to one of the others.
Here is the bandplan from the fcc.
Here are the radios at Best buy.
It's easier to fight for one's principles than to live up to them.
Lots of people have mentioned that Clear-Com makes a wireless unit. I have found better luck (with range and the battery time) with the HME (http://www.hme.com/) and Telex (http://www.telex.com/telexMain/) wireless units.
An added bonus is that it will interface with your existing theatre Clear-Com system! So for positions like sound, lights, and front of house who aren't moving much, they can just be using the existing system and you aren't spending money on batteries and unit maintenence. The stage manager, teacher, or general technical director can be on wireless headsets.
check with rental houses to see if they can sell you their older unit, or if they have any leads on where you can find a discounted unit. Lots of sales places will demo wireless units to prospective buyers, and sell the unit at a discounted price when the new model comes out.
I found this link over at
e com/telepho ne_intercom.html
"Use old phones as an intercom"
http://www.epanorama.net/documents/tel
The third circuit was hacked^H^H^H^H^H^Hthrown-together for a theater intercom and using two or more phones. Looks good, looks easy. I don't think it can to the ringing though. And I might use an old computer power-supply for the 12V.
"The more you sweat on EARTH, the less you bleed in SPACE."
I didn't read all of the threads so I apologize in advance if someone already mentioned this. Look into WVoIP. It uses very similar technology as the VoIP systems but you can use wireless headsets. Search Google News for WVoIP. I think that this technology could be useful, considering your current WAN in the school. It uses the same network. Typically on a large scale though it is on it's own network so that the traffic doesn't kill the servers. -Scott
Mwahaha....and did I make you burn _three_ modpoints on me?
/.
Yep.
The drop from "excellent" to "good" karma was worth it.
Anyhow, it sure was fun....heehee. Was it good for you? Sounds like it.
Right on....you came to troll, I came to flame...nothing like Friday night
Still, you gotta respect the cumstain on nova gag.
Given a choice between free speech and free beer, most people will take the beer.
Doh!
Stupid plaintext post.
Perhaps I should stop (drinking || posting)
Given a choice between free speech and free beer, most people will take the beer.
Considering ClearComm vs. Telex, I would go with Telex. It is compatible with ClearComm (unbalanced), but more importantly, it is balanced, so you will have less noise in the system. Also, the standard connectors are balanced 3-pin XLR, meaning they are compatible with balanced audio cables (However, I would buy a separate set of cables for intercomm use, and make them a different color, like blue - Clark Wire & Cable. This makes it easier to identify which cables are audio and which are intercomm and also ensures you won't use a beat-up intercomm cable for audio!). Also, Telex beltpacks are more rugged (metal, not plastic), and they look better! Look at Full Compass for intercomm hardware. They have good prices. Hope some of this is useful.
FreeHeel
This is really quite silly.. Trying to fit a square peg in a round hole if you ask me. Hardware Costs (size, weight, and battery life), software implementation, bandwidth, interferance and QoS limitations would make me think twice about utilizing 802.11 for a "simple" walkie-talkie.
How about using a technology everyone already has? Like.. a CELL PHONE..
Hell Nextel even has the "Walkie Talkie" feature.
Well, asside from the "My high school, like most others, has a Theater program (Which I assure you is not the case) AND the fact that you're invovled in said program. I will offer some help.... I think CISCO is releasing some kinda VoIP phone which runs on 802.11b/g handsets. They were like 200-500 bucks I think, but would do the job great I think.
First off, let me preface this by saying that i have worked building large-scale theater shows, and as a lighting designer for 7 years. I have worked on shows including the Lion King, Cher, Phanton of the Opera, Miss Saigon, Tim McGraw, the Pan American Games, as well as numerous regional and touring theater shows and outdoor festivals.
Quite literally the only thing these shows have in common is the need for clear, reliable crew communications. During setup/strike (installation/teardown), crews usually have portable radios (Motorola Walkie-talkies generally), so everyone can keep in touch without shouting or running around looking for each other. Essential for big shows, unnecessary but nice for small one. However, for all shows, only "Clearcom" communications are used.
Clearcom is a brand-name of wired "party-line" communications sets. It's used generically for other brand systems, like Telex, HME, etc. It's the same thing you see camera operators on TV shoots wearing. Everyone has a headset and beltpac, and can talk to one another on a common "channel". Everything is hard-wired, and everything works, all the time, every time. The systems is used for calling show cues, as well as any other necessary communication during showtime.
However, the "wired" issue becomes a problem for some people. While audio and lighting techs can often stay put (they sit behind a board), stagehand/stage managers have to be mobile, often on stage. Usually they need to be able to communicate in a high-noise environment, and it must work reliably.
The only way to do this is via a wireless clearcom system. Telex, HME, and Clearcom are the big three, and all of their systems are inter-operable. I personally like HME's RadioComm, but all systems have their own benefits. Simply put, these systems are expensive but necessary. For a school situation, you can probably get away with 2 wireless stations, and 4 wired. But you can't cheap out on this. You need great headsets, and equally good beltpacs to go with them. When you're midshow, and you can't hear your cue, you'll know why.
I hope this helps. I realize that you were looking for a cheap way around the problem, but there isn't one. You'll find that with 95% of things in theater, cheaping-out never works. You buy a crappy light, or sound equipment, or cleacom, and life sux but things go on. You cheap out on rigging or construction, and people die. It's as simple as that.
-Michael Roy
-Michael Roy Some people are like Slinkies. Not really useful, but you can't help smiling when you see one tumble down
My school always used Clear-com's. They're not incredibly cheap, but certainly better than a PC. You also don't need to go all out and get a real base station...the portable one does nicely. BenFranske is right that people need to be all over the place, but they don't always have to be connected. We had someone on each side of the stage, the people running the boards, and the stage manager all connected. The stations are wired together, but it shouldn't be hard to find someone to run the XLR for you, or you can just run it through your normal audio snake.
In my high school theatre we have a clear-com system that we use for general communication but there are times on our larger productions in which it simply will not do. To remedy this, a friend and I hacked together a system by which to patch our clear-com output into our assisted listening devices. After completing this, we could give our stage crew boxes which would allow them to hear anything that went on on headset. We have two wireless microphones (1 lav, 1 handheld) which we gave to important crew members and patched their output back into the clear-com system. This allowed them to have two-way wireless communication using our existing equipment. Aside from that, I have had mixed luck with FRS depending on the space (all used on small productions). Another idea, if you are wanting to have use computers for this solution would be to install terminals on the sides of the stage which would run a custom software solution that would display cue information upon receiving commands from the stage manager. (I almost built this last year.) Also, a simple IRC system would work as well if you wanted text-based messaging but other than that, I think that a dedicated communications system would do you good.
While I'm fairly sure that some variant or successor to 802.11* will be the norm for wireless phone handsets one day, I don't think now is a good time to solve that problem with it.
:v)
Soon there will be 802.11-enabled mobiles in common use and all those base stations will make an awesome ad hoc network, but until then I'd suggest PRS handsets and headsets with VOX to save power.
If anyone is interested, I've developed a concept for sharing browser caches over LANs to speed up the access of all members here.
Vik
I hope that was trying to be funny, as any set of kids walkie-talkies will work just as well and probably on the same frequency for much less. It sounds like they already have some crappy setup with similar quality, however, so this is a moot point anyway.
I am feeling fat and sassy
It is probably true... the political comments were what i was saying was off topic... not whether or not a particular person was good or bad.
The technical director at my college just switched us from a 15 year old clear com system starting to show its age to a set of Motorola talkabouts. All of us hate them and use the clear coms when he is not around since we prefer them for the headsets and the fact that we don't have to worry about batteries . Full duplex is also a great feature except when everyone is trying to shout each other down.
I work on my schools television station. Anything big like recording the school plays we usually do FRS radios. I've seen other setups use the unused 2-pairs of wire in the CAT5 network ports in the school as the local loop in a homebrew intercom system.
Use those Motorola radios that get like 1 mile range. They're like $50 for a pair plus $10 for some headsets to plug in. That's what most high school theaters use, cause they're cheap, work well and are simple to operate.
Get your school on a multiline phone plan with low minutes but unlimited push to talk...long distance walkie talkie that no one can look in on and you won't pick up anyone else's stuff...maybe you could do 4 phones for around $100 a month? That still might be too much, but with free or discounted equipment the initial cost shouldn't be too much, maybe around $600, with a monthly fee. Sprint, Verizon, and Nextel all offer unlimited PTT...(that is if phones would even work in your theatre)
Use the old phone trick. The parts are cheaply obtained, and not likely to get stolen. Plus, it works very well. The only downside is that you have to hold onto the handset. But there are solutions to that problem, as well.
there are 3 kinds of people:
* those who can count
* those who can't
get ham lisences for all of the tech crew, and as long as it is non profit i think that you should be able to do it. then radios will cost less and have more power.
Being a geek is a good thing. But it doesn't mean that you have to make things more complicated than they need to be.
You obviously need voice communication without (expensive) signalling. So analog voice will do just fine. Forget computer or networking based ideas, going there is only going to sidetrack you from your goal. Remember that this is about getting your theater group to communicate, not about playing with geek toys.
Someone here has already mentioned 49 MHz headsets. Radio Shack and Maxon are common brands and those should work great for you. But if you need something with a little less interference then......
FRS, or Family Radio Service is another option. The radios are fairly inexpensive and can be had for $30 each or so. They offer multiple channels and CTCSS tones (if you don't know what that means either RTFM or get back to me, it's worth your time to understand it). Those should give you the range you're looking for. You won't get interference from businesses there, that frequency band is for non-commercial use. And if you do find someone interfering then gather information and turn them in to the FCC and your interference problem is gone.
Beyond that you could go for commercial land mobile gear. It works like FRS but you have to license a channel. You do get a lot more power and range. The drawback is that the school will have to apply for a license and that takes time. You'll have to budget $300 on up for each radio with the accessories you'll want.
If it were me I would try FRS first, a trial run with a couple of borrowed radios.
. Quit playing Monopoly with Bill. Switch to one of many non-Microsoft products today.
mu_wtfo raises an excellent point regarding RF from wireless gear getting into equipment. 5 watts is enough to smoke a television -- literally. Accidently fried the soft power on a green room monitor with a 3 watt radio years ago. Even low output consumer wireless gear will present problems. For example, in the consumer space, GSM cellphones are especially problematic. They'll cause RFI headaches in nearly anything electronic. My video production organization needed to ban all RF emitting equipment from the production truck after GSM phones caused audio and video interferance during several live feeds.
they have great range, long battery life, and are private on whatever setup you have. Assuming you have less than about 6 people.
I tried for 5 years to come up with a clever sig...only to realize that I am not clever.
You may want to ask this question on the theatre-sound mailing list. This list has a broad and diverse membership, ranging from high school theater buffs (like you) to freelance reinforcement companies (like me) to the guys who actually build the hardware (like two of the techs at Cadac). Here's your link:
http://www.brooklyn.com/theatre-sound/
--Bennett Prescott
Former Lord Of Packets
Yup. You can get phones in the 900 MHz or 2400 MHz bands, so pick the one with less interference (and they're usually spread-spectrum, which is already a good start.) Just be careful about battery charging - my home Panasonics have really bad batteries for an otherwise nice 5-handset network.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
Channel-based systems are easy to tap. Spread-spectrum is much harder. (It'd be basically impossible, except that US eavesdropping laws limit the frequency-hopping rates to something the Feds can tap, but that's still beyond your average advanced hobbyist.)
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
Assuming that "Walkie Talkies" means the old AM CB kind, you should find that using more modern FRS, or preferably the more powerful GMRS (your school should have no problem getting the license), radios should solve your problem.n z5-htm
I use the motorola FRS radios every time I go anywhere outside the US, and my wife and I have no problem contacting each other in Hotels, malls, airports, etc.
Compare prices here: http://www.nextag.com/All~frs+gmrs+radioz0zB4zmai
I was wondering if anyone else has had the problem that I (personally) have had: if I have my headset on, and am at the sound board, I usually get RFI from the board, even with my hands hovering 6 inches over it. I'm not sure whether or not other people can hear it, and I can't test it because I am no longer part of the crew. However, I know that the interference was loud, and quite painful. As I didn't have my own copy of the script (I don't know what the stage managers were thinking...), I needed the headset desperately to hear my cues. As I was sound manager and we have a buggy system, I desperately need my hearing the best it can be to detect feedback before it is detected by the audience. You don't know how bad it is when I hear feedback now, after not having been on the show for over a year. I'm like a war veteran. Unfortunately, due to personal conflicts with the director of crew, I am no longer on the crew. He doesn't know what he's missing by not having me there. I'm serious. New guy, didn't have a clue what he was doing. He was arrogant, and acted like he knew what he was doing. I couldn't stand him, so I left. This was his first show and around my seventh. I knew exactly what I was doing, and he wouldn't listen to a thing I said. Unfortunate, considering I knew the wiring to the lights and sound, I knew the light board like the back of my hand having run it for several years, and I knew sound pretty well. Also, everyone that knew what was going on (ex sound-running-student and the old stage directors) all left, so I think that the manager is completely on his own. Sorry for the attached rant though.
SIG 666 - Signature stolen by the devil
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