Can system recording

[lukewebs]

I am trying to record the can system we have onto a DVD to use again for educational purposes we have tryed plugging the end of the can run into a mixer but because the wires are sending signals the yellow signal light gets stuck on so do u have to have an adapter or what do u recommend

[Andrew C]

I'd start by learning to spell "You". You will find that you get better responses that way!

 

Then you need to work out which wire in the comms system is carrying audio, isolate it with a DI or equivalent and record that. I suspect you've been shoving 24V into the input of your recorder, and/or sticking 48V phantom into your comms system.

[mac.calder]

And make sure everyone on the loop knows the show is being recorded...

[cedd]

Most master stations have a line output on the back of them - have a look for one of them before you start buying adapters.

 

 

Depending on the wiring of your system, pins 2 and 3 are going to have 24v and also the call lamp voltage on them. This DC is normally sat "on top of" the audio. Getting plain old audio out of the system isn't as straightforward as just plugging in. You'll need a transformer between whichever pin has the audio on it (on our system it's the same pin as the call lamp) and the ground (pin 1 normally). Then on the secondary of the transformer you'll end up with audio.

 

Can I suggest not going plugging stuff like that into mixers ever again! If you don't know how it works, or what the effects will be, don't do it!

[scjb]

And make sure everyone on the loop knows the show is being recorded...

Just in case you didn't see it the first time...

[gareth]

And make sure everyone on the loop knows the show is being recorded...

Just in case you didn't see it the first time...

What they said. Recording people's conversations on cans without their express permission to do so (especially if you intend publishing the resulting recording in any way, for example as part of the soundtrack of a DVD) would be very ill-advised.

[mackerr]

Most master stations have a line output on the back of them - have a look for one of them before you start buying adapters.

 

 

Which ones?

 

You can find out how to get audio without voltage out of a comm system here. Most comm systems are unbalanced audio, on either pin 2 or pin 3 depending on system, and channel. There will also be voltage to power the remote packs on one or the other, or both pins 2 and 3. You need to strip off the voltage with a capacitor, and balance and isolate the audio with a transformer. There is a lot of comm info on the downloads page of that same site.

 

Mac

[cedd]

Most master stations have a line output on the back of them - have a look for one of them before you start buying adapters.

 

Which ones?

 

Mac

 

Every system that I've used to date has had one. That said, having just done a bit of googling now, it seems that the current big players tend to go for speaker outputs (which I guess won't re-broadcast the local mic for feedback reasons) or an announce output (which I guess will only broadcast the local mic and not the ring). I was a little surprised when I looked myself. Seems the kit I normally use (stonewood, some ancient system - the name of which escapes me, and metro) is a little non-standard.

Quite a few of the ones I've just been looking at have a multiway "link" socket on the back of them - for chaining a couple of systems together. I guesss that as the rings are kept isolated, there will be plain old audio sat on some of those pins - worth investigating.

 

It all depends on the Op's master station.

[mackerr]

Every system that I've used to date has had one.

 

Very few of the systems I have used have one. It is pretty common to have an SA out,or it may be called "Announce" out, but I can't think of any major partyline system that has a line level output of the comms audio. Since most of the systems support multichannel in some way there would have to be an additional way to select which channel comes out of that port, something I have not seen on any system I am familiar with.

 

RTS MCE series speaker stations have a speaker that is separate from the rest of the station, and connects with a TS speaker cable. It should be easy to derive balanced audio from this, but since they are a lousy 4ch station they are not that common outside of broadcast OB vans.

 

Using a dry out box, or and audio only box like the one I linked to previously is the way I have seen recordings of comms traffic done.

 

Mac

[cedd]

The OP looks to be at a college in the UK - I'd put money on the system being either ASL, Tecpro or Stonewood (was Metro).

 

I agree, if there isn't a line output then your suggestion of an audio only box is the right way to go, but the stonewood system definately has a line out, so no need for the expense. It's worth his while checking.

[osal]

I don't know 100% but im sure somebody else will tell me I'm wrong.

the 4-pin XLR for a head set will be wired 2 pins for mic and 2 pins for head phones.

so if u got a 4-pin XLR surely you could wire something up to that

 

HTH

 

tom

[mark_s]

From the datasheet:

Pin 1 Microphone screen

Pin 2 Microphone signal

Pin 3 Earphones common

Pin 4 Earphones signal

[dbuckley]

Although you can connect stuff directly to a cans 4 pin, you really dont want to as you'll disturb the earth arrangements of the intercomms, and suddenly you'll be knee deep in dimmer buzz.

 

If you want to use the headphones out for record, you can, just get a small audio isolation transformer (about a fiver!) and then you can record headset audio without any collateral damage.