so...
i shielded out both of the J's and discovered that my plucking hand thumb and finger making occasional contact with the pole pieces was causing mahoosive amounts of earth hum - so i contrived a heath robinson affair of lining the cavity with shielding tap AND using some shielding tape to touch the underside of the pole pieces and also then contact with the pickup cavity - result quiet as a mouse no hum - the whole affair is kept in contact by means of pressure exerted from a large wedge of high density foam under the full lenght of the pup
question is, should the pole pieces be grounded like this? it has stopped the hum so didnt really question it before but seems a bit contrived so guessing it might not be a thing ???
or should i have insulated them completely from the shielding tape in the cavity
luckily the other basses have covered pickups so no problem of sausage fingers contacting the pole pieces but the J's have exposed pole pieces - but then so does my sberg electra and thay doesnt seem to have any earth hum issues when touch the pole pieces
tia