EMP Rules, Unwired vs. Arsenal Grudge Match Options

[Daishi]

I was flipping through Unwired today and came across some rules for EMPs at the end of the Hacker's Handbook section. They say to make an opposed test between EMP rating vs. Device rating (possibly including Electronic Warfare as well). But the only EMP generators I've found are in Arsenal: The EMP Grenade and HERF Gun. Both of which say to use a flat Device Rating x 2 (3) test. Is there another EMP source that I've missed (one that has a rating), or is this just one of those rule SNAFUs?

[Udoshi]

Its probably a snafu, and likely a case of the devs not cross-referencing their material.

You may want to go by date of publication.

I think I prefer arsenal's way of handing emp; though, in that affected antenna get -3 signal, instead of unwired's kind of handwavey 'compare the tables and make something up'.