VU3SQM directional wattmeter build – #3

VU3SQM directional wattmeter build – #1 laid out the first steps in design review and build of a directional wattmeter.

The parts have arrived and construction commenced.

Above, the PCB populated with the SM parts and soldered. It was soldered in an IR reflow oven.

Unfortunately I could not buy the 127R and 24R resistors in the package size to suit the board, so I have had to use 0805 packages and hand solder bridges to them. The trimmer cap does not exactly suit the through hole board mounts.

Now to wind the transformers, fit them and header pins, test and box the coupler…

… more as it unfolds…