The first consideration was the directional coupler. I remembered I had built one for the ill fated W7IEV project so this was unpacked. The basic unit is rated at 100W and has -40dB coupling for both forward and reverse signals. I found the fixed 20dB BNC attenuators bought for the W7IEV project so that would give -60dB for both forward and reverse signals.
I also found the two AD8307 detector boards from the W7IEV project so all I needed was to mount the Teensy 2++ arduino style module on a carrier board and was ready to go.
I mounted the modules and an LCD in a 8"x6" x 3" Box. Probably would have gone in a smaller one but it was available. The software was installed from Lofturs Site and all worked smoothly.
The software does have the ability to produce an alarm signal when a preset SWR is exceeded. This could be used to Inhibit an amplifier. It is the phono connector on the back panel below.
|Front Panel View (KX3 into two 50 ohm dummy loads)|
|Inside view. Teensy is on the left then 2 detector modules|