Back when these first hit the market I purchased a handful from a distributor just to experiment with later. Now after talking to Eric at Palomar they're telling me that these are a direct replacement for the 520 & 13n10's but couldn't provide a data sheet. I remember the original 2030's we would use companion parts that of course could be made with a couple of resistors and a diode. I guess where I'm going is, has anyone here used them and what results did you end up with? I know hard drive swears by them, but I have yet to see even the Palomar guys use the in their Magnum 1. (even though the original specs for that radio claimed to use them but used a 520 instead.)