Not really active cables but there has been at least 3 different mods on the attenuator part of the mic. The top portion with the cap. This mod eliminates the body and need for batteries. The mods have been called Franken Nak, Busman mod and more recently the JB mod. The mod would use either a phantom power module or the more recent Naiant PFA’s and your choice of cable length.
Unfortunately no one is doing the mod anymore so you would have to find a set in the yard. They do pop up a few times a year. Put an ISO out and I’m sure you will find them. I’ll try to post some pics of mine when I get a chance.