We could probably quite easily add support for an electronics effect to the SEXP, but it doesn't seem to be able to do it now.
That would be nice in the long run but, forgive me ignorant mortal for saying this, but this would take longer than I would like - esspecially considering it might require adding new parameters to the SEXP (and of course the unfortunate snowball effect, I just realized this would have in regard of other weapons flags like the leech effect)
Use weapon-create
Sounds good ... I'll have to test that, shouldn't be too hard to table a weapon with the requisite parameters and keep it spawning inside the ship I want to have the pulse originate from