I am trying to set up an intercom in a WWII tank. It is an extremely high noise environment and the system employed throat microphones to help with this.
There is no existing intercom but we do have some original headphones and microphones.
We have been using a portable Nav-Data aircraft intercom and it functions fine using standard aircraft headsets. To me, there is nothing uglier than a wonderful looking WWII tank rumbling by with the crew wearing modern aircraft headsets.
The problems we have been having are:
1. The noise in the driver's position is so loud that the microphone is feeding the noise back into the system. The driver needs both hands to steer the tank at all times so it needs to be vox.
2. The original headphones are 1000 Ohm per ear and I think the throat microphones are 300 Ohm. We can get either original equipment working or modern but not both at the same time. Obviously there is an impedance mismatch.
3. The Nav-Data has a couple of external connections for an mp3 player and a recorder. I would like to use that to hook up to a GMRS/FRS/HAM walkie-talkie to communicate with other vehicles. This sort of works but it is erratic.
Our goals are:
1. Be able to use the original headphones for the two exposed crewmen.
2. Be able to use original throat microphones or replace them with modern throat microphones designed for a GMRS radio.
3. Allow the radio operator and/or the commander (co-pilot/pilot) to switch over to the GMRS radio to communicate with event staff.
4. Allow music to be played over the intercom.
As I see it, I will need to build some impedance matching circuit boxes to insert at the various change-over spots. Each crew position has a plug in box that can hide the circuits and multiple types of connection points.
I have enough electronics knowledge to know that I am out of my depth. I have built some breadboard circuits but never made a proper circuit board.
Does anyone have any suggestions?
Neil
There is no existing intercom but we do have some original headphones and microphones.
We have been using a portable Nav-Data aircraft intercom and it functions fine using standard aircraft headsets. To me, there is nothing uglier than a wonderful looking WWII tank rumbling by with the crew wearing modern aircraft headsets.
The problems we have been having are:
1. The noise in the driver's position is so loud that the microphone is feeding the noise back into the system. The driver needs both hands to steer the tank at all times so it needs to be vox.
2. The original headphones are 1000 Ohm per ear and I think the throat microphones are 300 Ohm. We can get either original equipment working or modern but not both at the same time. Obviously there is an impedance mismatch.
3. The Nav-Data has a couple of external connections for an mp3 player and a recorder. I would like to use that to hook up to a GMRS/FRS/HAM walkie-talkie to communicate with other vehicles. This sort of works but it is erratic.
Our goals are:
1. Be able to use the original headphones for the two exposed crewmen.
2. Be able to use original throat microphones or replace them with modern throat microphones designed for a GMRS radio.
3. Allow the radio operator and/or the commander (co-pilot/pilot) to switch over to the GMRS radio to communicate with event staff.
4. Allow music to be played over the intercom.
As I see it, I will need to build some impedance matching circuit boxes to insert at the various change-over spots. Each crew position has a plug in box that can hide the circuits and multiple types of connection points.
I have enough electronics knowledge to know that I am out of my depth. I have built some breadboard circuits but never made a proper circuit board.
Does anyone have any suggestions?
Neil
