Beyer DT108 Headset/Mic On A GP300

[mrtor]

Hi All From Sunny Melbourne, Australia
I have a customer who uses Beyer DT108 Headset/Microphone combinations on their wired talkback system (a clearcom compatible job)

They now want to use these on their Gp300's with a little adapter cable.

Question is:

Beyer Headsets use a 200 ohm Dynamic Mic and they don't want to change the mics as they want to be able to swap from radio to wired talkback

Anyone got some sort of clever way to do this (I am assuming the Gp300's use an electret insert)

Any help appreciated
Mike

[mrtor]

Anyone ??

[Sam]

I did this with HT90's a few years back. I just took the cable from a speaker mic and put the mating headset connector on the end. We used to use DT108's for a while; I'll have to dig one out and give it a try.

We use an RTS (now Telex) system though, which is not compatible with Clearcom. RTS uses a 4-pin XLR connector, separate mic and speaker circuits and dynamic mics. If I remember right, Clearcom uses a 3-pin headset, and I don't know whether the HT90 uses a dynamic mic.

Have you just tried it to see if it works?

[mrtor]

If I remember right, Clearcom uses a 3-pin headset, and I don't know whether the HT90 uses a dynamic mic.

Have you just tried it to see if it works?

The clearcom uses a 4 pin cannon/xlr connector for the headsets.

No I have not tried it as I understand that the GP300 uses an Electret Mic where as the Beyers have a Dynamic...

Don't want to try just in case something goes "PUFF" and becomes expensive to fix.

From my memory of about 15 years ago when we had some HT90's we had to change the mic inserts to Electrets on our headsets... They worked well but for this application changing the insert is not an option, they have to remain cross compatible.

Cheers
Michael
from a suprisingly WET Melbourne, Australia

[PRR]

You'll need a small capacitor to block DC voltage (5V, 47uf is small and works well) as well as a resistor (about 500ohms, 1/8 watt). Take a speaker/mic cable and solder the cap and resister in series on the mic+ lead of the cable (white, I believe) and to pin 2 of the 4 pin male XLR. Both components should fit within the XLR shell.

You may have to use the GP300 software to adjust the mic gain on the radio to achieve the appropriate level.


And . . .

We use an RTS (now Telex) system though, which is not compatible with Clearcom. RTS uses a 4-pin XLR connector, separate mic and speaker circuits and dynamic mics. If I remember right, Clearcom uses a 3-pin headset, and I don't know whether the HT90 uses a dynamic mic.

Although system impedances are different, beltpack headset connectors are wired the same, whether it's four (mono ear feed) or five (dual ear feed) pin. Only the sex is different (male for CC, female for RTS).

Henry

[mrtor]

[quote="PRR"]You'll need a small capacitor to block DC voltage (5V, 47uf is small and works well) as well as a resistor (about 500ohms, 1/8 watt). Take a speaker/mic cable and solder the cap and resister in series on the mic+ lead of the cable (white, I believe) and to pin 2 of the 4 pin male XLR. Both components should fit within the XLR shell.

You may have to use the GP300 software to adjust the mic gain on the radio to achieve the appropriate level.


Thanks Henry, I was just about to give up hope on this thread ....

I will try this out and see how we fair. Thanks again
Michael

[mrtor]

[quote="PRR"]You'll need a small capacitor to block DC voltage (5V, 47uf is small and works well) as well as a resistor (about 500ohms, 1/8 watt). Take a speaker/mic cable and solder the cap and resister in series on the mic+ lead of the cable (white, I believe) and to pin 2 of the 4 pin male XLR. Both components should fit within the XLR shell.

You may have to use the GP300 software to adjust the mic gain on the radio to achieve the appropriate level.


Thanks Henry, I was just about to give up hope on this thread ....

I will try this out and see how we fair. Thanks again
Michael