The only frequency related component in the schematic might be C4, but even that probably isn't too critical - it probably depends more on the transducer than anything. And yes, the output is AC coupled through C4, although I wouldn't be able to tell why without guessing (reduce capacitive loading/attenuate output signal, match transducer capacitance with transformer inductance to make a tank, dunno).
The shape of the label around TXP-AMP says that it's an output - it might either be a test point or it might be fed into some other part of the circuit. Maybe something else measures it so that they can calibrate the output power or something.
T1 jist indicates that it has a 12 to 235 ratio, and that the primary can have a dozen amps or so going through it (dunno how much resistance the primary winding would have). The transformer core itself will have to support ~200KHz signals, so it should probably be a powdered iron or ferrite core. You can probably wind it yourself if you want... Or use one of the transformers out of a computer switching power supply.
The shape of the label around TXP-AMP says that it's an output - it might either be a test point or it might be fed into some other part of the circuit. Maybe something else measures it so that they can calibrate the output power or something.
T1 jist indicates that it has a 12 to 235 ratio, and that the primary can have a dozen amps or so going through it (dunno how much resistance the primary winding would have). The transformer core itself will have to support ~200KHz signals, so it should probably be a powdered iron or ferrite core. You can probably wind it yourself if you want... Or use one of the transformers out of a computer switching power supply.