Intercom Issues

[Mauser]

Recently we've been having issues with our intercom system, and among many problems, one of the biggest has to do with our wired packs.

We have a Telex system with the two channel wired packs, however, with probably over half the packs, whenever you hit the talk button it will change the channel that the pack is on instead of talking, any idea on what could have caused this or why it's happening?

 

[Mauser]

OK, I really hate to bump threads, but I've waited about a month and have 2800 views and no replies, does anybody know what could cause this, I really need these packs working by mid February, does anybody know?

 

[avkid]

Let's start from the beginning.
What models are the base station and packs?

Do they only do it when plugged into a certain cable or place in the system?
Have you shifted around the packs?

Has your cable been verified for correct termination?

 

[epimetheus]

To add to avkid's list:

Have you talked to someone at Telex? I don't know much about Telex, but I sat on the phone with the engineer who designed the Clearcom CS-222 main station while he walked me thru repairing mine. The manufacturer should be your first recourse with possible equipment failure. Who knows the product better than the people who built it?

 

[Mauser]

I'm not sure on the model, I'll check next time I get a chance.

It's not an issue with the cable, I've tried multiple packs on the same cable, and gotten some that work and some that don't, plus when daisy chaining them, one will not work, and then one further down the chain will work just fine.

 

[avkid]

Do you have the problem if only one cable is plugged into the base station?

 

[Chris15]

I've moved this post over to the Sound forum where comms issues normally get more attention.

Further to the other questions, how old and how abused is this system?

 

[kfox]

Take the base station (rack mount or otherwise) and unhook everything. Take it out of the rack (to eliminate something strange in the grounding, I've seen this be the problem). Place it on the bench and grab a few cables that you have checked the pin config on (verify 1-1, 2-2, 3-3 and NO "case" ground, ie: pin 1 also connected to the case of the plug). Now connect a beltpack or two and start testing. Eventually you should find:
A: that you add a cable that causes the problem
B: that you add a beltpack that causes the problem
C: that you reconnect the "house" wiring and THAT causes the problem
D: the problem exists with any cable/pack and therefore is in the base station itself

We had a problem with a ClearCom that existed for at least a year. We sent the base back twice and finally realized the problem was in the "house" wiring. We only figured this after taking the base with us on a road show and noticing the hum was gone. We tracked it down to one wall jack having the ground touching the metal gang box. This is why I suggested taking the unit out of the rack (if applicable).

Good luck! Let us know what you find. Telex is also used extensively in TV work, so you may also want to try a TV board for help. Or, as has been suggested, try Telex themselves. If they want you as a customer, they will at least try to help you. Otherwise, ClearCom makes a great system!

Best,

kfox

 

[Mauser]

kfox, I'll try that and get back to you, but the rack is pretty mobile, we move it around a couple times a year, and the problem occurs everywhere we use it.

 

[Morpheus]

kfox, I'll try that and get back to you, but the rack is pretty mobile, we move it around a couple times a year, and the problem occurs everywhere we use it.

Have you talked to the people at telex?

 

[museav]

The comment that they could daisy-chain beltpacks and have one not work but one further down the line work fine at least seems to indicate it is not a simple house wiring problem as one would expect that to affect anything connected.

A quick look at the Telex BP-2002 manual finds on Page 3 the statement "On the BP-2002, if no headset is connected, when the Talk button is pressed, the Talk button will have the same function as the Chan button.", perhaps that has something to do with it.

 

[Mauser]

That might be the issue, a lot of our headsets lately haven't been working, so that would make sense, if we happen to be testing it with a headset that doesn't work.

 

[Chris15]

Telex neglect to mention how they are detecting the absence of a headset, so we can only guess how they are "detecting" it. It's possible that this circuit is malfunctioning - these are microprocessor controlled after all or simply that it's behaving per spec with the broken headsets...

I would guess that the pack is either looking for mic or speaker impedance - so perhaps you can work it out based on what's wrong with each individual broken headset...

 

[Mauser]

Ok, this was the problem that we had, and we are now in the process of inventorying all out headsets, and fixing the broken ones.

Thanks everyone for the help, it saved me many hours of problem solving.