A-weighting filter for HP 8903B


2011-12-12 1:12 pm
Is anyone interested in obtaining an A-weighting plug-in filter for their HP 8903B?

I've searched around trying to find one for my own 8903B but have been unsuccessul. The service manual has the circuit diagram, so I have therefore built my own. I have slightly improved the performance of the original HP design by replacing the TL074 op-amp with an AD8513 and laying out the PCB for surface-mount components.

If other people out there are interested in getting hold of one of these filters, I could investigate manufacturing a batch of them. I've not worked out the cost yet, but I'm guessing that it will come in at around £100 / $150 / €120.