Fixed Price: Less than $500
| Posted: Jun 19, 2015 | Ends: 6h, 7m |
My intent is to mimic this transmitter but improve on it a bit [obscured] /2009/06/command-transmitter-by-dave-martin.html?m=1 It would be nice to have band modules by that i mean in the schematic above the band is changed by L6 - L7 and C13-16 this would be nice to be able to just changer out a module for the and i want and then the crystal to get me on frequency the idea is in a emergency situation i want to be able to broadcast a audio file from a device into the transmitter via the shortwave band(s) this transmitter must have a low pass filter so any out of transmitted band harmonics are filtered out this filter must be modular and be swapable inline with the tx so when i change frequency i can change filters as well Transmitter must be capable of producing a minimum 25w output Transmitter must be build on a pcb (no bread board no dead bug no perfboard) This project includes you building a physical working prototype This project includes you designing the ...
Fixed Price: Not Sure
| Posted: Jun 15, 2015 | Ends: 11d, 4h |
I am looking for someone to do PCB layout for a startup company. The board should contain eight transimpedance amplifiers, that can operate with high gain (1e8), high bandwidth (2e5 Hz acceptable, but prefer going up to 1e6 Hz), with low noise. These amplifiers would be used for applying a fixed voltage, and measuring small currents (less than 10 nA). To get an idea, a similar, acceptable layout can be found at: [obscured] /datasheets/1599345.pdf (though this board is for 1 amplifier, and not 8. Specifically looking for a board configured in transimpedance configuration, measuring current and applying a fixed voltage). Also, there are likely to be better opAmp packages that can be mutually agreed upon. These circuits are for high precision applications, so low leakage currents, low voltage drift, and low noise are all required. If possible, would also like to keep the size of the board to that of an Arduino header. If this is not possible, two boards of the Arduino size w...