Homemade wireless Telex.

[CSCTech]

Hey guys,

We were planning on getting a intercom system (be it telex, production intercom or clearcom) this year but I dont think it is going to happen, maybe next year. Or even middle of this season, not sure. But not the beggining I know, so I am going to ask the AV department if we can borrow their telex system for one of our shows. They use it during the schools few large events they record.

Its a really old system but works. It has a box that you plug power into, then ~6 cat 5 inputes which run to the beltpack, the beltpacks have headsets connected to them.

Now I am wondering, for the stage hands I think the wires would be a bit of a hassle, but I was thinking. If I were to get a wireless house phone-

And connect the output of that into the main box, have the wireless handset with its own power, get a headset for the wireless phone (I know some phones have these plugs.), hit the intercom button or call/on button on the handset and presto?

I am not sure if this would work or not, any ideas?

 

[amain07]

cheap and/or self build coms system

does any one know of a way of building a cheap comms system or even where to get one very cheap.

 

[derekleffew]

... Its a really old system but works. It has a box that you plug power into, then ~6 cat 5 inputes which run to the beltpack, the beltpacks have headsets connected to them. ...

If it's a "really old system" it can't be using CAT5 cable, as the RJ-45 connector hasn't been in use that long. Much more common, since the early 1970s, is to use 3pin XLR microphone cable between base station and belt packs.

... Now I am wondering, for the stage hands I think the wires would be a bit of a hassle, but I was thinking. If I were to get a wireless house phone-
I am not sure if this would work or not, any ideas?

Yes, wires are a hassle, but in many, many cases, less of a hassle than wireless. How many people need to go father than a 50' cable will reach? Perhaps the time will come when everyone on the crew will just be on a conference call on their cell phones to run a show, but I doubt I'll live that long. Clear-Com (and PI and Telex and others) has accustomed us to (relatively) inexpensive, reliable, full-duplex communication that has yet to be surpassed.

I expect that cordless phones could dial a landline, and then other stations could join in, but the number of stations would be limited. Teaching people to mute their mics when not speaking would be a necessity, just as it is with any icom system. See also Headset "etiquette" - ControlBooth.

 

[Footer]

A POTS (standard telephone network) and a telex/clearcom network work completely different from each other. You can not just plug in a telephone into a clearcom system and expect it to work. In fact, you will probably smoke the telephone.

 

[derekleffew]

True, but a Clear-Com AC-701 is only about $800.

Never used one; have no idea how/if it works.

 

[Stookeybrd]

Its a really old system but works. It has a box that you plug power into, then ~6 cat 5 inputes which run to the beltpack, the beltpacks have headsets connected to them.

Sounds like an old "4wire" system, which use a "phone cable" and either a RJ-25 or RJ-14/11 plug. Even though they use the same connectors, the wiring for power, audio and common are very different compared to phone lines. In fact be careful, you may short out the phone or the Telex system if you connect them together.

 

[CSCTech]

This is not a Clearcom system.

I know what clearcom and even new Telex system are look like and how they work but this is very different from those. I am not sure the date on this system, but it does use standard telephone cable, which I believe is Cat 5? Sorry if I am mistaken. The headsets are actual hardwired into the beltpack.

 

[Shillyer]

This is not a Clearcom system.

I know what clearcom and even new Telex system are look like and how they work but this is very different from those. I am not sure the date on this system, but it does use standard telephone cable, which I believe is Cat 5? Sorry if I am mistaken. The headsets are actual hardwired into the beltpack.

Cat-5 refers to Category Five cable, which is a twisted pair cable very commonly used for networking. The Cat-5 qualification however has nothing to do with connector type. RJ-45 connectors are usually put on the end on Cat-5 cable for ethernet/computer networking cables. Standard phone connectors are usually RJ11, RJ14, or RJ25 as Stookeybrd said.

While technically you can use Cat-5 cable to carry phone signals, it is most common for someone to refer to Cat-5 and expect it to have RJ-45 connectors (Ethernet cable). This, however, is not technically accurate as Cat-5 cable can be fit with many different connectors (Ethercon for example).

Feel free to correct me if I misspoke.

 

[Footer]

While technically you can use Cat-5 cable to carry phone signals, it is most common for someone to refer to Cat-5 and expect it to have RJ-45 connectors (Ethernet cable). This, however, is not technically accurate as Cat-5 cable can be fit with many different connectors (Ethercon for example).

.

Cat 5 cable with RJ45's is actually speced for 4 line phones. If you have ever wondered why a RJ45 connector is wired in w/O O w/G Bl w/Bl G w/BR BR has to do with how the old phone systems worked. The center pair was one line, the next outside pair was line 2, the orange pair was line 3, and the brown pair was line 4. RJ45 connectors were in use way before ethernet even existed. Modern office phones such as nortel, toshiba, etc use the center (blue) pair to communicate with the PBX. Ethernet over copper up to 100mbps only uses the orange and green pair to communicate to avoid sending ringing voltages down the line. Gigabit ethernet does use all 4 pairs. Many offices will just wire every jack with cat 5 so that they have the possibility of using a standard phone, computer, digital phone, or IP based phone all over one type of cable. The cost savings of running cat 3 over cat 5 is nothing compared to the labor. So... don't always expect a Cat 5 cable with RJ45's to carry ethernet....

 

[2mojo2]

To the Original Poster:

You can't afford what you want now, and there are insurmountable technical problems with connecting the stagecom system directly to wireless.

Here is how to do it on a shoestring for as long as you must>
Get a set of Motorola Talkabout units or similar very basic walkie talkies.
Get headsets to match.
Combined cost, if you shop hard, maybe $60 per stagehand on wireless.

NOW
one unit goes on an assistant stage manager.
the stage manger passes messages to the assistant, who communicates with all those stagehands on wireless.

the stage manager is on the wired stagecom loop, communicating as usual with SOUND, LIGHTS, ETC.

This plan allows you to leverage the available equipment at minimal cost, and avoids putting the stage manger on two communication loops at once.
You use the wireless loop only when needed, and the stage mangager is insulated from any cross-talk between the wireless units.

The walkie-talkies come in handy now and then for other purposes as well.
For example, light techs can use them so they don't have to shout from booth to house to cats.


I hope this helps you until you can buy a new system.

 

[CSCTech]

Thanks for the idea mojo,


I am only wondering if what I said would work, I would love to get a real system but it just isn't going to happen before the next show.
When I say Cat 5 I really don't know if it is. The wires connecting everything in this telex system are everyday telephone cable and connectors, I am not sure of what the name of the cabling is, but its the same as if you where plugging in your home phone to a household outlet.

If it wont work it wont work was just an idea. I know the owners of this system have bought a spool of the wire and made their own couple hundred foot extensions.

Thanks~

 

[Shillyer]

Cat 5 cable with RJ45's is actually speced for 4 line phones. If you have ever wondered why a RJ45 connector is wired in w/O O w/G Bl w/Bl G w/BR BR has to do with how the old phone systems worked. The center pair was one line, the next outside pair was line 2, the orange pair was line 3, and the brown pair was line 4. RJ45 connectors were in use way before ethernet even existed. Modern office phones such as nortel, toshiba, etc use the center (blue) pair to communicate with the PBX. Ethernet over copper up to 100mbps only uses the orange and green pair to communicate to avoid sending ringing voltages down the line. Gigabit ethernet does use all 4 pairs. Many offices will just wire every jack with cat 5 so that they have the possibility of using a standard phone, computer, digital phone, or IP based phone all over one type of cable. The cost savings of running cat 3 over cat 5 is nothing compared to the labor. So... don't always expect a Cat 5 cable with RJ45's to carry ethernet....

Thanks Kyle for putting it in clearer words than I,

I do understand that many corporate/industrial applications make use of RJ-45 for other purposes, including phone lines. I assumed when the OP mentioned "Telephone Cable" He was not referring to RJ-45 which is less common for home phone use. I was simply stating that while it is not technically correct many people may refer to it in that manner. The reference to ethernet was simply so someone reading would easily understand what a RJ-45 connector looked like.

Anyways more on topic, if you could even get the system wired and working correctly it sounds like a bad idea to me. Wireless coms are well developed and reliable, I feel even after spending a lot of hours creating this system you would not get the performance or reliability you would want to put in a live show situation. Many stagehands and theaters can survive without wireless headsets. Simply learning how to be mindful of your cable can do wonders. I would say spend the time and energy developing and implementing a reliable wired system, it is always easy to add wireless functionality if you have more capital to spend on it down the road.

 

[CSCTech]

Yes, like I said this was only a very cheap idea to hold us over until we can get a real system installed. I will see how the full wired system goes.
Also another reason I thought of this is because now I need a 200+ foot cable . In my theory the phone reciever would sit near the station in the booth.

Anyways, I am sure I can scrap together something be it walkie talkies, a borrowed Clear Com or the wired telex system. We have been running shows with no communication what so ever for years, anything helps!

Just out of curiosity, say I had $2000, what kind of ClearCom or Production Com system would that get me? With minimum 3 headsets and max we would ever use 5.

 

[museav]

Just out of curiosity, say I had $2000, what kind of ClearCom or Production Com system would that get me? With minimum 3 headsets and max we would ever use 5.

So a basic, single channel, party line system with power supply, 3-5 beltpacks, 3-5 headsets, cabling, connectors, etc. Probably something like this, econocom. You could wire up as many outlet locations as you want but would be limited to a maximum of 10 beltpacks in use at once, perhaps less if some of the runs are real long.

And just a detail, but "RJ-45", "RJ-11", etc. refer to the pin assignments or wiring, not the physical connectors. RJ-45 connections uses 8P connectors, typically 8P2C for telephone connections and 8P8C for Ethernet connections, while RJ-11 conncetions use 6P connectors. This seems nitpicking but it can be relevant in situations like this where it could be an 8P or 6P connector used but not for a RJ-11 or RJ-45 connection.

 

[Chris15]

And just a detail, but "RJ-45", "RJ-11", etc. refer to the pin assignments or wiring, not the physical connectors. RJ-45 connections uses 8P connectors, typically 8P2C for telephone connections and 8P8C for Ethernet connections, while RJ-11 conncetions use 6P connectors. This seems nitpicking but it can be relevant in situations like this where it could be an 8P or 6P connector used but not for a RJ-11 or RJ-45 connection.

Because things weren't already interesting enough, RJ11 to me is a 4P connector, as used for the cable between handset and telephone, and RJ12 is the 6P variety...

 

[CSCTech]

Interesting, I will be looking into the econo com then. They way the site makes it seems is you do those by custome orders?

As for wiring terminals I think I have that figured out, any connections needed within the booth can just go straight to the station, and then I am thinking use two empty channels on our snake, that would run the cable backstage to the where it is wired up to the amp rack and area mics, also, we have about 5 xlr outputs around the stage that where never wired, but are ran to the amp rack but stop. Who knows why..
Anyways was thinking if I could rewire one of the outputs near the snake to connect it to one of the ones on the other side of the stage then there you go. Hoping to not have to do more than that.

 

[CSCTech]

Heh, just found the ordering section of the site, and wow I had no idea that the most expensive package (1 station, 4 beltpacks 4 single muff headsets) is only $990.

 

[Chris15]

I would strongly suggest going for dual ear headsets over single eared. Single ears generally fatigue the wearer much more quickly because of the imbalanced loading and pressure on the head...

 

[museav]

I would strongly suggest going for dual ear headsets over single eared. Single ears generally fatigue the wearer much more quickly because of the imbalanced loading and pressure on the head...

The usual "it depends" from me on this. I agree with Chris's point but also like having an open ear to be able to hear what is going on and people yelling "Watch out!" when they aren't on comms or forget to push talk, especially in school and community theatre settings. You need to decide which makes the most sense for your use.

 

[CSCTech]

Interesting, I didn't think of that. But like museav said, I am afraid of the users not hearing other things, like the sound op is going to get a muffled version of his mix.