Finished my meter (amp)

So just wanted to post a few pics of my finished meter.

I got the head a few months ago, a coherent 210, it outputs 1mV/W. It's a bit impractical so, the amplifier changes that signal to 1mV/mW.


Fun exciting black box! I'll add some info on the top later.


Thermopile and multimeter in a group photo. I zero the output on the meter, and it gives me min/max/avg too. <3 fluke.


Inside view. DIY RF shield.


DC-DC converter off two 14500 cells. (~8V up to 30V) And an extra filtering board with a 1uH inductor, 1mF cap, a few tantalums and ceramics.


View of the signal end of the box, the inputs and outputs. Using an RCA socket/plug to retain coaxial shielding.


And the circuit. Using a TI TLE2426 to split the rails, using a LTC1150 chopper amp as the main opamp in a non-inverting configuration. Vishay BC resistors and a bourns pot in the divider. Antiparallel diodes on the input to protect the opamp. the hot glue is only there for structural integrity


And a view of the underside, not that complex. It sits in the slots in the sides of the box, so the bottom of the board is near the RF shield.

So there it is. Feel free to ask questions.


aXit.

Very nice. Excellent job on the amp.

Oh, and I forgot to add. It works brilliantly!

No noise on the output, never hovers much more than 1mV away from a zeroed output.

I'm really happy with the turnout.

AXit that looks great! Enjoy your new meter +Rep for great work.