Wednesday, March 20, 2013

RAI Intercoms

As a result of some recent inquiries we've written up some new details regarding the capabilities of our flight simulation intercom units, including a couple of new diagrams that might be of some use also.

Our intercoms are not normally supplied with microphone and headphone sockets, but we are able to supply aviation microphone sockets, and stereo headphone sockets, and indeed we have recently supplied some special Helicopter Headset sockets because they have the mic and phones on the same plug.

Heli Sockets

All connections to our intercom boards is via screw terminals.

The microphone input circuitry is suitable for most microphones, and can even be readily configured for very low impedance microphones as used in some military and vintage headsets. (or Oxygen masks)

There are on-board adjustments for the gain of the microphone, and the level of the "side-tone" (so you can hear your own voice).  There are also volume adjustments for the audio signals coming from the PC, and because we can drive stereo headphones, you can hear cockpit / engine sounds coming from the correct location.  There is a master volume control fitted on a short cable to enable you to fit it into your panel as required.

There are several modes of operation for the intercoms, with two pairs of terminals which control the outgoing audio. These are logic levels only, so you can fit remote buttons and switches, because there is no audio signals on these wires.

1. One allows you to connect a 'Push to Talk' button so that the other pilot can hear you only while you hold the button down, or you can just put a small wire link between the two terminals and you can be heard all the time. (Open Microphone) 

2. The other pair of terminals allows you to connect an 'Enable' switch to enable or disable the audio going to the Flight Simulator PC. If you want audio to go the Flight Simulator PC all the time, just put a small wire link between the two terminals.

3. Another option is to connect the system so that you have an Open Microphone (as in 1 above) and then use a ‘Push to Talk’ button on the Enable terminals. The means that the pilots can hear each other all the time, but the push to talk button controls what goes out to the Flight Simulator PC. (e.g.  as a radio call etc.)

4. If you use a double pole push-button  (one pole connected to the ‘Push to Talk’ terminals, and the other pole connected to the ‘Enable’ terminals) you can effectively have a push to talk button so that the other pilot can only hear you whilst the button is depressed, and also your voice only goes out to the Flight Simulator PC while the button is held down.