Neutron Filter, which Optoisolator?

[JonL]

Hi, can anyone recommend which optoisolator gives the best result in the GGG / RG Keene Neutron Filter? VTL5C3? CLM6000? NSL32? Do the 2 devices need to be matched for best results? Thanks for any advice!

[R.G.]

I believe small bear electronics stocks the original Hamamatsu part.

You can't use one of the centertapped parts, because the two LDR sections need to be separated.

Two of the VT/NS/CL/etc. parts will work OK. Ideally they should be matched, but matching is very much more difficult with LDRs, and previous builders have found that modest mismatches still give usable results.

[jdub]

Unfortunately, looks like Steve at Small Bear ran out of the Hamamatsu part, the P873-13.  I was looking for one of these a while back for a Mini-Qtron build; I ended up using a couple of VTL5C3s instead- pricey, but ended up working pretty well.  Since each is a single LDR & LED, I just wired the LED leads in series.  You can also try rolling your own...