The resistor for the MSA0270 is calculated as
R = (Usupply - 5V) / Iamp
We desire to run the amplifier at 25mA current and plan to feed it with 12V, R must be (12V-5V)/25mA = 280 Ohm (or closest value).
The amplifier itself is built directly on a piece of single sided copper PCB into which I have cut a couple of incisions with the dremel drill and a router bit. Ideally, the board should be double sided and the dimensions of the stripline should be calculated according to the PCB material to achieve a precise 50 Ohm conductor. For this case, as the receiving loop anyway operates up to 7 MHz only, the dimensions of the stripline are uncritical.
The two capacitors are 100n ceramic types.