Help with IR repeater needed

I built my own IR repeated a number of years ago and found it in the bottom of my junk bin. It was based on the GP1U52X IR detector. See the attached schematic. Can I replace the GP1U52X with the stereo Y splitter and the 2 detectors I have that came with my Comcast digital cable adapters?. What factors are involved in being able to run multiple parallel detectors? Also since these detectors are plastic encased units with a stereo (3 conductor) plug on the end, how do I determnine which pin is Vcc, Ground and Signal? Do I risk damaging it if I use trial and error to connect it to my repeater? If I can't simply connect them through a Y splitter, any suggestions on a mod to the circuit to support 2 detectors? Any help or suggestions is greatly appreciated.

Infra red domestic remotes tend to use 40khz 'toneburst', and aplliances often have a monolithic receiver within, whereas upon a modulated 40khz transmission the receiver module gives a logic 1 or 0 output (there is an amplifier and 40khz tone decoder within the ir receiver module).
The module your project used is monolithic and gives a logic output, according to its datasheet.
I'd expect that the little 'blips' you get with some equipment also to have a monolithis receiver module, that being the case opne of these would probably work with your circuit.
Finding the connections for the blip might be a little tricky, make a little lead plug to socket, then break out the three connections, you'll be able to suss out which is power with a meter, and the data connection will give itself away with either a scope or logic probe while you point a remote at the blip and press a button, if you havent got either then connect a speaker via a 1k resistor to the connection you'll hear the codes.
You might just need a 1k pullup resistor to the positive supply.

can two of these be connected in parallel using a Y connector? Also, you mentioned figuring out which pin is power using a meter. How do you do that?