Hello Stefan,

I have purchased some SFH250V's  and SFH757V's.

I assumed that the SFH250V is a photo transistor like the SFH350V,  however it is a photo diode and requires additional circuitry.

Thank you for the link to the LT6200.

Unfortunately RS does not sell to private persons in the Netherlands.

However Mouser does, and though they don't carry the LT6200 they sell as equivalent the AD690ID.

As it will take some time before I order again at Mouser, I will try to use a circuit with discrete parts first.

For a start I will use the mini-whip buffer amp.

Avego suggests a circuit with a AD8015, which is even more expensive than the LT6200!

I will let you know how it goes.

73,

Roelof Bakker, pa0rdt