Peltor and Trisquare Integration

I have been running into the problem of integrating my peltor headsets and my trisquare TSX100 radios. The peltors are a powered unit, and can be seen here:
http://www.peltor.com/peltor.com/comm_detail.cfm?prod_family=Service%20Intercom%20Hea&ind_prod_num=MT72H7A-40001

I have so far been able to have the trisquares recognize that the headsets are attached by having a resistor across the mic and ground wires and using the VOX feature on both the radios and headsets. I have tried a few different values and added in bypass caps with no luck so far. I has just wondering if anyone would have any suggestions on how to integrate the 2 units together. Thanks in advance.

Hmm, a powered intercom.

Are you trying to re-use your Peltor headset with the TriSquare radio, or use the radio to extend the range of the Peltor system without a wire?

I’d suggest if you’re just using it as a headset, try to get as much of the Peltor stuff out as you can. Don’t use the powered box (if this unit has one), try to make the headset as much of a ‘dumb’ device as you can.

Curious, what exactly have you gotten it to do and what hasn’t worked yet?

The peltor headset is a powered unit and uses a wired system. The amplification is in the earmuffs and I would prefer to keep it in its stock configuration.

I am trying to take the output of the peltor unit and have it transmitted over the trisquare radio. The radio uses a threshold of 7mV to activate it’s VOX. The peltor’s output is about 80-120mV. I tried using a basic voltage divider network but that did not work.

well the trisquare is probably operating a very simple setup, if it uses a standard 3-wire 2.5mm- mic+, spk+, and common ground. It’s looking for certain amounts of impedence/signal on both the mic and spk circuits, so you need to match that.

In comparison, from what I remember of those wired intercom headsets, the audio is handled much the same as a telephone- there is ONE audio circuit, not two (tx and rx). IE, Power+, Audio+, and Common Ground. Note that in your brochure it suggest the headsets can be made to work just by plugging them all into each other with splitters, this also suggests a one-circuit design. However it would help to know exactly what the jack of the Peltor has (2 wires? 3? 4?), what their impedences are, if you’ve identified them as TX/RX, etc.

I suggest you grab a cell phone headset (2.5mm jack), and test the impedence of both circuits. Chances are they’re the same for cell phones as the Trisquare radios, but I could be wrong- you could pick up a shoulder clip mic for trisquare to also figure out what it does for PTT.

Now on the radio interface, put audio isolation transformers on both the MIC and PTT circuits. If you’re keeping the guts of the headset, this is probably a good idea anyway. On the radio side, add resistors in series to add some impedence (if the transformers don’t give the right amount), then you have 4 wires which need connection to the headset.

This is the part I’d need more detail to really help with- if the headsets use one audio circuit, you’d need something similar to a telephone hybrid circuit (google it). That converts the 2-wire phone interface into a 4-wire one (1 tx pair, 1 rx pair)

hope that helps…