Batboard

Hello!

For quite some time now, I've been trying to get my nexus U94 PTT to work properly with my Saber. Took the remainders of my handmic (with the Saber connector) and used the same cable to rewire the PTT. What I've kind of figured out so far is that I need the PTT to work with around 1.25 V. To get the radio to recognize external devices the "opt sel" is to be connected to ground with either diodes or a 5 k ohm resistor. I tried the latter, but still no success! I get the audio to work with my headset but it still doesn't seem to bypass the internal speaker. Can't get the PTT keying to work either.

Any help (wiring diagram or such) on this subject would be most appreciated!


Cheers!

/Tom

There are several different voltages on the line for different functions. I know someone posted them a while back.

After much grief in trying to interface different headsets to my saber radio I finally broke down and tore into my Tactical Command Headset to see how they interfaced it. The key to everything is a little precision voltage regulator that is a LM285M-1.2. This is a SOIC device and I just wired 2 leads to each side of the chip. One side goes to the OP Sel pin and the other goes to ground to proivde the needed 1.25 volts on the op sel line to allow the remote accessory switch to occur. These regulators are available in a TO-92 format but found the smd one is best as it is small and was easy to solder some very small leads to to make the conneting in the mic connector or in the wires going into the headset. The page on batlabs talks about a zener diode to do this, which is in escence what this regulator kinda does. Once this is done the sabers and astro sabers will switch the audio to the external pins as needed. Just wire the mic to mic, ear to ear, PTT to the ptt to the right pins and away you go. I think the chips I got were from Jameco and were in stock at about 0.38 each so I got a few to play around with. I've interfaced my 35th headset for our guys here converting military combat headsets designed for the MBITRS to our sabers. They've worked great and hold up better than anything else we could find. I wish I had known about this chip earlier and it would have made interfacing these things alot easier.

firemedic wrote:After much grief in trying to interface different headsets to my saber radio I finally broke down and tore into my Tactical Command Headset to see how they interfaced it. The key to everything is a little precision voltage regulator that is a LM285M-1.2. This is a SOIC device and I just wired 2 leads to each side of the chip. One side goes to the OP Sel pin and the other goes to ground to proivde the needed 1.25 volts on the op sel line to allow the remote accessory switch to occur. These regulators are available in a TO-92 format but found the smd one is best as it is small and was easy to solder some very small leads to to make the conneting in the mic connector or in the wires going into the headset. The page on batlabs talks about a zener diode to do this, which is in escence what this regulator kinda does. Once this is done the sabers and astro sabers will switch the audio to the external pins as needed. Just wire the mic to mic, ear to ear, PTT to the ptt to the right pins and away you go. I think the chips I got were from Jameco and were in stock at about 0.38 each so I got a few to play around with. I've interfaced my 35th headset for our guys here converting military combat headsets designed for the MBITRS to our sabers. They've worked great and hold up better than anything else we could find. I wish I had known about this chip earlier and it would have made interfacing these things alot easier.

Hi!

Its been some time sins you posted this but I having the same problems. And don't quite get your explanation. When I look inside the monophone the send button is working trough the same pin (#7) that need 1.24V to change the radios modes. Your talking about "Just wire the mic to mic, ear to ear, PTT to the ptt to the right pins and away you go." Don you need to place the LM285M-1.2 parallel with the PTT button?

Do you have a wiring diagram of your successes? =)

Regards
Wille