Well the HP 66312A turned up here today.
Bummer: despite what ought to have been reasonable packaging by the seller, Parcelfarce managed to smash the shrouds on the terminals.
![](https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/?action=dlattach;attach=1154290;image)
I've given it a brief functional checkout and the basics all work. In doing so I discovered an interesting feature, the fan speed is directly proportional to the
measured output current (or perhaps power). It doesn't change after a thermal lag, it changes immediately the measured output current changes. Neat.
By the way, this is the heaviest 40W PSU I've ever encountered. In fact, I'd go for it being the heaviest PSU in terms of kg/W that I've ever encountered - excluding PSUs that only put out a 100 mW or so, where they're hitting the limits of how small/light you can practically make something that plugs into the mains.
Edit: Just calculated from the specifications: 4.54 W/kg.