You would not use diodes but you would need a two pole (two wafer) six position (probably rotary) switch. Each switch position selects one lug from each wafer, the chosen lugs are always one behind the other. Each position connects one pickup from each wafer (or one pickup from one wafer and no pickup from the other wafer).
I take it that both chosen pickups go to the same amplifier input in which case the common terminals of the two wafers are tied togehter to become the hot line (center conductor of the coax cable).
For example, the second pickup is used in both the second and third switch positions so you connect it (using a jumper wire) to the second and third lugs of one of the wafers.The first pickup is used in both the first and second positions so you connect it to the first and second lugs of the other wafer. This way no two pickups are connected to each other except during the switch positions where both pickups are to be used at the same time.
The disadvantages of crab apple trees. In summer, the apples are too sour to pick and eat. In winter the birds come and leave dropping all over the place.
Last edited by AllanJ; 06-05-2011 at 02:47 PM.