Converting to ClearCom Headsets?

[doggmann]

Hi all!
So, I dug out an old hard-wired ClearCom base station (CS-222) and a couple belt packs (501s). All seems functional, but we don't have any headsets, ClearCom 4-pin F XLR. However, we've got quite a few other headsets that I'm attempting to convert to the 4-pin XLR.

I found a pinout from another post for ClearCom, and I'm able to trace the speaker hots and grounds, mic hots and grounds...and I've had a little success, except in the mics.

If I feed a program input into the base station, I can hear it in the base station headset as well as the beltpack headset, so I got the speakers in the headsets working it seems. I can hear clicking when I hit the call buttons on both the base station and belt pack, but I can't get anything out of the mics on the headsets.

The most surprising incident was when I made contact with the mic hot solder point, and the belt pack call button was locked, I suddenly was picking up radio stations on both headsets. I think I was acting as an antenna and feeding that into the mic hot.

Any hints? Is there a ground or phantom power fed from the base station or something else that I'm missing that I can't get anything from the mics on the headsets?

Thanks!

 

[eadler]

What was the original connector on them? How were they wired? How are they wired now?

There's a switch (or maybe a jumper) inside the beltpack for microphone type - do you have that set right?

 

[doggmann]

What was the original connector on them? How were they wired? How are they wired now?

There's a switch (or maybe a jumper) inside the beltpack for microphone type - do you have that set right?

The original was for Kenwood walkies.

One headset had no PTT button, so simply had the four wires, two for speaker, two for mic.
The other headset was an OTTO brand, with a PTT. I bypassed the button (always on), traced the hot and grounds on both ends and wired accordingly.

As for the beltpack mic type, my beltpack only has a high and low setting for the mic. I've tried, both, nothing.

thanks!

 

[teqniqal]

Have you looked at the Kenwood radio microphone circuit to see if it uses a bias voltage for an electret type mic? I found a few references to 8vDC for some Kenwood radio mics, so they may use an electret type capsule. If it does, then you need a way to get that DC voltage on the electret mics without blowing-up the ClearCom belt-pack mic preamp. It may be more trouble than it's worth. Headsets are cheap, just take care of them and sanitize them between uses (don't spread the hair, skin, and spittle spooge).

 

[doggmann]

Have you looked at the Kenwood radio microphone circuit to see if it uses a bias voltage for an electret type mic? I found a few references to 8vDC for some Kenwood radio mics, so they may use an electret type capsule. If it does, then you need a way to get that DC voltage on the electret mics without blowing-up the ClearCom belt-pack mic preamp. It may be more trouble than it's worth. Headsets are cheap, just take care of them and sanitize them between uses (don't spread the hair, skin, and spittle spooge).

Ah, but that's my issue - headsets are not cheap for ClearCom. $75-$250 a pop, and when 3 are needed it becomes a hurdle. Trying to just knock over that hurdle. What would I look for to see if it's using DC voltage?

 

[teqniqal]

Look at DataVideo: http://www.datavideo.com/us/product/HP-1 & http://www.datavideo.com/us/product/HP-2A for some reasonable priced headsets. Also look at: ProIntercom (http://prointercomllc.com/category/headsets-handsets/) -- this was formerly 'Technical Production' brand intercom -- the headsets are very comfortable.

As to the microphone bias voltage, if any, get a service manual or data sheet from Kenwood for the headset you have, or the radio it was designed to work with. Adding an external bias voltage system, if needed, will result in you having to add a battery holder / compartment and (continually forever) remind the user to turn-off (or remove) the battery each time they are finished using it (and to install / turn-on the battery each time they want to use it. -- No good deed goes unpunished.).

 

[jtweigandt]

If all else fails, and you need some comm on the cheap, Take a peek at the mumble threads.. I know it would be neat to use the stuff you have,
but you have to look at your time, and not throw good money after bad.

 

[eadler]

As for the beltpack mic type, my beltpack only has a high and low setting for the mic. I've tried, both, nothing.

That's the switch on the outside, is it not? There's a switch or jumper block inside for electret/dynamic and, iirc, some models have a carbon mic option. There are other options set inside that may make your beltpacks behave different than you expect as well. Check the switch/jumper details in your manual.

 

[DrPinto]

I noticed that you called the wires "hot and ground". They're more like "positive and negative". Just double checking your wiring...

Pin 1 is the mic negative (braided shield)
Pin 2 is the mic positive
Pin 3 is the speaker negative (braided shield or wire)
Pin 4 is the speaker positive

DO NOT mix up or connect the two shields together or jump pins 1 and 3.

Also DO NOT connect anything to the shell terminal of the plug. Only connect to pins 1 thru 4.

From the Clear-Com manual:
Mic Type --- Dynamic; 150 to 250 ohms impedance; -55 dB output level
Headphone --- Dynamic; 50 to 2000 ohms impedance

Hope this helps!

 

[EdSavoie]

We've got a clear com system of that generation.

The weakest part of the headsets is the connection to the microphone element, there is a good chance that either the solder, or the teeny-tiny single strand copper wires have been severed.

 

[tibfibber]

Since you're in the Bay Area. might be worth a trip down to Alameda, or at least a call directly to ClearCom. A good friend of mine recently dropped into the ClearCom offices with a collection of the original rs-100 beltpacks & headsets, and a plate of cookies. She ended up spending some time with the lead engineers, and left with more then she came in with (well, minus the cookies).

Admittedly, it was a slightly unorthodox way to get some tech support; but when I realized that ClearCom was literally down the street from us, and might be interested to see some of the original gear, still in use...

Clearcom

• tibfibber
• Apr 6, 2018

Americas and Asia-Pacific Headquarters
Clear-Com, LLC
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Alameda, California 94501
United States
Tel: +1.510.337.6600 or 1.800.462.HELP (4357)
Fax: +1.510.337.6699
Email: [email protected]

http://www.clearcom.com/contact/support-contacts