Adapter cable for twin channel Clear-Com

[samchurchill]

Hi,

I've got a Clear-Com RS-602 that I want to connect to a two single-channel TecPro systems and program audio.  (They're not actually TecPro, but they use that standard.)  I've built a breakout cable as per the diagram at 

(where it's far better drawn than my version!) but am getting some strange results.  When I plug in the 3-pin XLR for comms channel A into the TecPro system the other belt packs on the system lose power and the RS-602 doesn't seem to have any power.  This is before I plug in either channel B or the program audio.

Do I need to be making the cable in a different way?  As far as I can find from info online, the pin-out is the same on Clear-Com and TecPro single-channel systems, it's just the voltage which is slightly different, but I was hoping to get away with that.

The only other thing I can think of is that I had to use an off-the-shelf XLR gender bender at the last minute - could this have swapped pins 2 & 3?  Unfortunately it's at a venue that we only have access do during our weekly events, so I'm keen to try to solve it before next Sunday!

Any help or advice greatly appreciated!

[sunray]

41 minutes ago, samchurchill said:

Hi,

I've got a Clear-Com RS-602 that I want to connect to a two single-channel TecPro systems and program audio.  (They're not actually TecPro, but they use that standard.)  I've built a breakout cable as per the diagram at 

(where it's far better drawn than my version!) but am getting some strange results.  When I plug in the 3-pin XLR for comms channel A into the TecPro system the other belt packs on the system lose power and the RS-602 doesn't seem to have any power.  This is before I plug in either channel B or the program audio.

Do I need to be making the cable in a different way?  As far as I can find from info online, the pin-out is the same on Clear-Com and TecPro single-channel systems, it's just the voltage which is slightly different, but I was hoping to get away with that.

The only other thing I can think of is that I had to use an off-the-shelf XLR gender bender at the last minute - could this have swapped pins 2 & 3?  Unfortunately it's at a venue that we only have access do during our weekly events, so I'm keen to try to solve it before next Sunday!

Any help or advice greatly appreciated!

First off, be aware there are 2 different styles of 6pin XLR

 

If it's any help I've  made some of these and copied what I believe were commercial units:

Seems to be some variation on the top sketch: ie 2 male XLR3's, A&B busses flipped on 6 pin and a flip in the program audio. This was too far back to remember what the system & combination was.

Bottom appears to be 6pin infrastructure cabling to beltpacks.

 

For the same person at the same time but I have no idea why:

 

[James Remo]

https://clear-com.atlassian.net/wiki/spaces/SF/pages/158713454
 

I’ve had mixed results using a dual channel canford belt pack from two seperate canford psu’s, the line termination needs to be observed (for instance, if one 3 pin gets unplugged the belt pack goes unstable and you get squeals of feedback in the headset. If you build a termination circuit into an XLR you can - with varying degrees of success- run a dual circuit beltpack from a single psu)

The cable you have made will connect both psu’s +24v lines together at your headset. Canford produce a box to interface between two psu’s - https://www.canford.co.uk/TECPRO-COMMUNICATION-SYSTEM-System-Combiner - note they stress the importance of not joining two psu’s together. 

Edited May 16, 2023 by James Remo

[sunray]

8 hours ago, James Remo said:

https://clear-com.atlassian.net/wiki/spaces/SF/pages/158713454
 

I’ve had mixed results using a dual channel canford belt pack from two seperate canford psu’s, the line termination needs to be observed (for instance, if one 3 pin gets unplugged the belt pack goes unstable and you get squeals of feedback in the headset. If you build a termination circuit into an XLR you can - with varying degrees of success- run a dual circuit beltpack from a single psu)

The cable you have made will connect both psu’s +24v lines together at your headset. Canford produce a box to interface between two psu’s - https://www.canford.co.uk/TECPRO-COMMUNICATION-SYSTEM-System-Combiner - note they stress the importance of not joining two psu’s together. 

If this is aimed at me, I must reiterate this was from about 2016 and all I did was make additional cables by copying existing. I don't recall the purposes of each and the only one I have a note of is the bottom of first pic where it shows 'YC6 to packs' and assume used to plug packs with 3pin connectors into infrastructure wall box.

The guy would have come back to me if there was anything unexpected.

Edited May 16, 2023 by sunray
Oh dear that sounds critical but not meant to be. I do understand the issues of linking different power sources but I suspect it didn't apply to these.

[sunray]

20 hours ago, samchurchill said:

 

The only other thing I can think of is that I had to use an off-the-shelf XLR gender bender at the last minute - could this have swapped pins 2 & 3?  Unfortunately it's at a venue that we only have access do during our weekly events, so I'm keen to try to solve it before next Sunday!

Any help or advice greatly appreciated!

Just remembered I purchased some 3pin gender benders which looked just like 2 Neutrik connectors screwed together which had 1&2 reversed. I've also purchased mic cables wired the same way.

[Jivemaster]

As purely a random guess; the nominal "shield" pin may or may not be automatically connected to the body of the connector and this may (or not) be wanted in a "belt pack" application.

[sunray]

1 hour ago, Jivemaster said:

As purely a random guess; the nominal "shield" pin may or may not be automatically connected to the body of the connector and this may (or not) be wanted in a "belt pack" application.

I'll say allowing the shield (assuming it is the 0v line of the intercom) to become connected to any other ground or earth is usually not wanted. In fact it's very likely to create problems. Such a contact is more likely if using building infrastructure, especially if run withing earthed metal containment or multicore (stage) cables where other circuits could have a similar shield/body connexion.

[Jivemaster]

Any screened three pin XLR lead will have the description "microphone lead" especially if it's origin was China. Most times these leads have the screen connected to the metal body of the connectors.

Probably the OP could completely rebuild lots of their leads, carefully breaking any unintended connections to the connector chassis. Currently I can't find enough plastic bodied connectors to be useful, and the few that seem suitable have a metal tag or latch.

[sunray]

And I am just as guilty of using the generic term: 'microphone leads', just as the use of 'Hoover' or more usually these days 'Henry' or 'Henry Hoover' etc.

[samchurchill]

Thanks everyone. So, unless I’m missing something in your replies, it sounds like there’s no fundamental problem with the design of the breakout cable I’ve made, which is good news.

I’ve asked the venue’s technician who lent me the fender bender to test that it see whether it crossed pins 2+3 over.  I’m also going to retest all connections I’m my cable and replace the XLR male with female so the gender bender isn’t even needed.

It also sounds from James’s reply as if I shouldn’t connect it to both powered channels - luckily this was just a nice side benefit - it’ll almost always only be needed on a single channel, so will tackle that when we come to it.

[timsabre]

The diagram you linked to at the top was for connecting 2 single channel beltpacks to dual channel loop wiring which is the opposite of what you want to do.

To connect a dual channel beltpack to 2x single channel loops, which I think is what you are wanting, you need to take power (pin2) from only one of the single chan systems, otherwise you link the power supplies together and this will cause bother as you experienced.

You need to wire as Sunray's top picture (ignoring the 3rd XLR3 connector).

(If you need to get power from either of the single channel loops, you can use 1n4001 diodes to link the power together from the 2 loops)

[samchurchill]

Thanks, that makes sense, and is indeed what I’m wanting to do. However, the strange thing is that the test I did was only connecting it to one single-channel loop (i.e. I left the 2nd xlr unplugged), so is that not still a mystery? 

[samchurchill]

Well, the good news is that I’ve tested the cable again and found that a short had appeared on pins 1+2 between when I built it and when I first tried to use it. Having fixed it, I’m now hopeful that it’ll work when I am next at the venue.
 

On 5/17/2023 at 11:11 AM, timsabre said:

(If you need to get power from either of the single channel loops, you can use 1n4001 diodes to link the power together from the 2 loops)

This would actually be really handy, in case others start plugging it in - is it just a case of adding a diode on pin 2 of each of the XLRs connecting to the single-channel loops?

thanks again

[timsabre]

9 hours ago, samchurchill said:

This would actually be really handy, in case others start plugging it in - is it just a case of adding a diode on pin 2 of each of the XLRs connecting to the single-channel loops?

Yes... (will attempt drawing)

Loop 1 pin 2 -----|>|-------|
                            O -------- pin 2 to beltpack
Loop 2 pin 2 -----|>|-------|

 

[sunray]

Yes that looks good, here's the CC drawing with the extras added in orange