Inline Foot Switch for Clear-com headset

[James Sargent]

I had a LD come through on a tour with a foot switch for his headset, and decided to make one for myself.

My venue has an SB-704 Clear-Com base station and we use the RS- 601 belt-packs with CC-300 and 400 headsets.

Added a switch on the Mic Hot line on Pin 2 and combined the shield and Mic low on Pin 1 and direct pass thru on the speaker lines.

When I plug the switch on the SB-704 I get a high pitch tone when the talk is not engaged. When I turn the talk on it goes away, and the switch works as I wanted but there is still a little buzz on over the line with or without the switch on.

Where is the fault? I'm suspecting it's in the shield but how can I fix this.

Thanks
Jim

 

[RonHebbard]

I had a LD come through on a tour with a foot switch for his headset, and decided to make one for myself.

My venue has an SB-704 Clear-Com base station and we use the RS- 601 belt-packs with CC-300 and 400 headsets.

Added a switch on the Mic Hot line on Pin 2 and combined the shield and Mic low on Pin 1 and direct pass thru on the speaker lines.

When I plug the switch on the SB-704 I get a high pitch tone when the talk is not engaged. When I turn the talk on it goes away, and the switch works as I wanted but there is still a little buzz on over the line with or without the switch on.

Where is the fault? I'm suspecting it's in the shield but how can I fix this.

Thanks
Jim

@James Sargent You want to wire your switch to short the mic when you want it off, you DON'T want to open the circuit. I haven't Googled your headsets but I'm making the assumption you're using normal Clear Com headsets with unbalanced microphones, not anything fancy from the world of broadcast with balanced microphones. Continuing my assumption: If your headsets have standard Clear Com four contact connectors, you want to wire your switch so it shorts contact 2 to contact 1 when you want the mic off and removes the short when you want your mic on / able to speak. Questions? Fire away.
EDIT 1: Shorting the mic element won't hurt the dynamic mic and simultaneously shorting the mic input should give you a switch which operates silently and click free.
EDIT 2: A tidy way to accomplish your wiring would be to purchase an in-line XLR4 female / male barrel connector and drill and file a neat hole in the side of the barrel to receive the shielded cable leading out to your foot switch. This would make it easy to insert your remote switch with any pack or station and easy to remove and transport. I did a similar trick with an XLR-3 barrel connector so I could insert my Ward Beck extended range VU meter in any balanced XLR-3 cable from mic level to line level without having to worry about Phantom power when present. With the cable entry / exit hole chamfered and filed smooth, I was able to fold the cable 90 degrees flat against the side of the barrel connector and secure it with one or two Ty-Wraps.
Toodleoo!
Ron Hebbard.

 

[Chris15]

Might I recommend that a capacitor inline with the switch might be prudent.
Some beltpacks provide bias power for electret mics, and as a general rule one would try to avoid shorting a DC connection when not absolutely necessary...

 

[Aaron Becker]

I wish I would've come up with this idea so many years ago. Dang it. Watching this thread...

 

[RonHebbard]

Might I recommend that a capacitor inline with the switch might be prudent.
Some beltpacks provide bias power for electret mics, and as a general rule one would try to avoid shorting a DC connection when not absolutely necessary...

@Chris15 You MIGHT recommend a capacitor but if you look at how Clear Com mutes their own headset mics by rotating the boom over head, I doubt you'll find a capacitor included. I suspect you'll find they're simply dropping a short across the output of their dynamic mic.
Toodleoo!
Ron Hebbard.

 

[themuzicman]

I've always used a DPDT switch for this task -- one side of the switch passes Mic Hot and Mic GND to the headset, the other just shorts Mic Hot and Mic GND to itself.

If I'm feeling really fancy I'll bump the switch to a 4PDT and grab a 9V battery and a light that can be powered off the 9V and wire it in to give me visual feedback when I'm muted/unmuted.

 

[RonHebbard]

I've always used a DPDT switch for this task -- one side of the switch passes Mic Hot and Mic GND to the headset, the other just shorts Mic Hot and Mic GND to itself.

If I'm feeling really fancy I'll bump the switch to a 4PDT and grab a 9V battery and a light that can be powered off the 9V and wire it in to give me visual feedback when I'm muted/unmuted.

@themuzicman A 3PDT could do that and save the space and cost of a fourth pole or you could do it with your DPDT if you went with an LED which was lit when muted. Lit when live would increase battery life.
Toodleoo!
Ron Hebbard

 

[Aaron Becker]

I'm curious what everyone's thoughts on the momentary PTT vs maintained switch is? If I was going to leave my comms hot all the time, I probably wouldn't need the foot pedal. Also, what pedals are all of you using for these projects (product links suffice)?