I made my amp/meter and interface last week, but haven't tested the PC side yet - had to deal with a failed power supply on the PC! So this is not a report on that unit, though I'll get around to it soon...
But I wanted to plug this thought in before everybody gets theirs made:
I know people often ask where to get metal project boxes... and I found an excellent source for free!
Having paid $27 or so for red burner laser diodes, I decided to use the boxes they came in - that is, the DVD burner housing! It's nearly perfect - roomy but compact, strong, stable... and if I wanted, it could be mounted in my computer (and use its power).
The front panel of the DVD unit is easily modified, being just ABS plastic. It was fairly simple to cut out holes for the dpm, coax connector, and gain adjustment; and a slot under the dpm for the zeroing pot - a slide unit. The PC interface connector and the AC power jack are mounted on the back.
I decided to go with plug-in power, not liking batteries for essentially stationary equipment. So there's a small transformer (from a wall-wart) with a very simple circuit to make the split-rail supply. The jack is from my dead PC supply, so it takes the standard computer-equipment line cords.
By the way, there is a
lot of good stuff in that DVD unit! makes the LD a real bargain with all those 'free' extras.
I'll post pics later... it isn't pretty though, I just kind of roughed it out - but I have a few more dvd housings to make a final version ;-)