R
RST Engineering \(jw\)
- Jan 1, 1970
- 0
I am thinking about creating a new design for transceiving audio over a
range of a couple of meters. The criteria are as follows:
1. Up to four audio sources each of which must hear all of the other three
stations. (Headset-microphone-earphone) Although I'm not ruling out any
scheme, what I think would work is a "base station" that could be mounted
somewhere in the vehicle, receive up to four separate frequencies, and
retransmit the detected audio over a common transmit channel.
2. Fairly high electromagnetic intensity environment ... tens of watts of
RF at 120-140 MHz. at a meter or so range. Hundreds of peak power watts
(average 5 watts or so) at 1 GHz. also at a meter or so.
3. Entirely possible that in some instances the device will have to operate
in direct sunlight. I'd prefer not to use opto techniques.
4. Whatever the technology and power source, the device will have to be
worn on the head for several hours at a time. It may be possible to mount
the device on the chair the person is sitting on but I'd like to keep my
option open to mount the whole works inside the individual headset.
5. Moderately high noise environment made a little more liveable by the use
of noise-cancelling microphones.
6. If at all possible, I'd like something that will work in an amateur
radio band...the device will only be marketed with proof of amateur license.
2 meters might work, as would 220 or 440. 220 is so quiet that I'd really
like to operate in that band if possible.
I'm not so much looking at a design per se, but more a technology or
device(s) that I could research and see what is available and preferable.
Comments appreciated.
Jim
range of a couple of meters. The criteria are as follows:
1. Up to four audio sources each of which must hear all of the other three
stations. (Headset-microphone-earphone) Although I'm not ruling out any
scheme, what I think would work is a "base station" that could be mounted
somewhere in the vehicle, receive up to four separate frequencies, and
retransmit the detected audio over a common transmit channel.
2. Fairly high electromagnetic intensity environment ... tens of watts of
RF at 120-140 MHz. at a meter or so range. Hundreds of peak power watts
(average 5 watts or so) at 1 GHz. also at a meter or so.
3. Entirely possible that in some instances the device will have to operate
in direct sunlight. I'd prefer not to use opto techniques.
4. Whatever the technology and power source, the device will have to be
worn on the head for several hours at a time. It may be possible to mount
the device on the chair the person is sitting on but I'd like to keep my
option open to mount the whole works inside the individual headset.
5. Moderately high noise environment made a little more liveable by the use
of noise-cancelling microphones.
6. If at all possible, I'd like something that will work in an amateur
radio band...the device will only be marketed with proof of amateur license.
2 meters might work, as would 220 or 440. 220 is so quiet that I'd really
like to operate in that band if possible.
I'm not so much looking at a design per se, but more a technology or
device(s) that I could research and see what is available and preferable.
Comments appreciated.
Jim