I think I bit off more than I could chew by deciding to build a multiplying interferometer based on AD8302 amplitude phase comparator board from Amazon. I am very grateful to Julian Palmer from Rosliston Astronomy Group who came around last night and spend 2.5 hours sorting my attempt out!
The AD8302 board was itself not working and sonehow turned 5V input into 48V! Thankfully, I had accidently purchased a spare one, so we could replace it.
Also, virtually everything else I had done didn’t work including me soldering power wires onto wrong pins on bulkhead power connector!!!
He also bought an oscilloscope so we could test it.
Now, I need to try the new version in the field……