I tried simply running the emitters in parallel, but it appears that theres not enough current from the UIRT itself to do so, so I need an external signal amplifier. Ideally something small thats powered by the internal 12V power supply of the machine.
A quick internet search resulted in this schematic, albeit for a different product:

I presume this would work with the USB-UIRT and Xantech emitters, but figured I'd check here first to see if anyone has any other suggestions.
Thanks much in advance!!