5:1 AC Step Down Transformer

lemming:
Just read that the coil needs to be 'read' at the same time so the above may be moot.

And that indeed, is the "trick".

Using a single-chip implementation of this sort of function prevent you from using "outboard" amplification in the separate transmit and receive paths.

And a "plain" op-amp is not the most suitable for these frequencies.

A mentioned before, you must assume the design is already optimised to obtain the best performance from the parts available and that no "simple" modification - if even practical - will drastically enhance its performance.